(Vol.65 No.10 2001)
Structure of Green Pigment Formed by the Reaction of Caffeic
Acid Esters
(or Chlorogenic acid) with a Primary Amino Compound
Goro YABUTA, Yukimichi KOIZUMI, Kazuko NAMIKI,1 Mitsuhiko HIDA,2 and Mitsuo
NAMIKI3
p.2121
Development of Free Radical Products during the Greening Reaction
of Caffeic Acid Esters (or Chlorogenic Acid) and a Primary Amino Compound
Mitsuo NAMIKI,1 Goro YABUTA, Yukimichi KOIZUMI, and Midori YANO2 p.2131
Effects of Rooibos Tea Extract on Antigen-specific Antibody Production
and Cytokine Generation in Vitro and in Vivo
Kazuyoshi KUNISHIRO, Akihiro TAI, and Itaru YAMAMOTO† p.2137
Regulation by Two CatR Proteins that Differ in Binding Affinity
to catB Promoters Expressing Two cat Gene Clusters
Atsushi TAKASHIMA,1 Shuichiro MURAKAMI,2 Shinji TAKENAKA,2 and Kenji AOKI2,†
p.2146
Influence of Adenine-induced Renal Failure on Tryptophan-niacin
Metabolism in Rats
Tsutomu FUKUWATARI,† Yuko MORIKAWA, Fumiko HAYAKAWA,
Etsuro SUGIMOTO, and Katsumi SHIBATA p.2154
Superoxide- and 1,1-Diphenyl-2-picrylhydrazyl Radical-scavenging Activities
of Soyasaponin β g Related to Gallic Acid
Yumiko YOSHIKI,1,＊ Takashi KAHARA,1 Kazuyoshi OKUBO,1 Terumi SAKABE,2
and Terumasa YAMASAKI2 p.2162
Orotic Acid Added to Casein, but not to Egg Protein, Soy Protein,
or Wheat Gluten Diets Increases 1,2-Diacylglycerol Levels and Lowers
Superoxide Dismutase Activities in Rat Liver
Yoritaka AOYAMA,† Mizuho WADA, and Masashi MORIFUJI p.2166
Phosphoglucose Isomerase from Bananas: Partial Characterization and
Relation to Main Changes in Carbohydrate Composition during Ripening
Beatriz Rosana CORDENUNSI, Jo<Oh><0227><Wa>ao Roberto Oliveira
do NASCIMENTO,
Renata Vieira da MOTA, and Franco Maria LAJOLO† p.2174
Supplemental Silk Protein, Sericin, Suppresses Colon Tumorigenesis
in 1,2-Dimethylhydrazine-Treated Mice by Reducing Oxidative Stress
and Cell Proliferation
Siqin ZHAORIGETU,＊ Masahiro SASAKI,＃ Hiromitsu WATANABE,＊＊ and Norihisa KATO＊
p.2181
Characterization of The Cellulose-Binding Ability of Geotrichum sp. M111
Cells and Its Application to Dehydration of The Distilled Waste
of Sweet Potato Shouchu
Hidefumi YOSHII,† Takeshi FURUTA, Miyuki IKEDA, Takatoki ITO,
Haruyuki IEFUJI,＊ and Pekka LINKO＊＊ p.2187
Chemistry of Zerumbone. 2. Regulation of Ring Bond Cleavage
and Unique Antibacterial Activities of Zerumbone Derivatives
Takashi KITAYAMA,1,† Kaneyoshi YAMAMOTO,1 Ryutaro UTSUMI,1 Masahiro TAKATANI,1
Richard K. HILL,2 Yasushi KAWAI,3 Seiji SAWADA,4 and Tadashi OKAMOTO1 p.2193
Increased Energy Metabolism and Suppressed Body Fat Accumulation
in Mice by a Low Concentration of Conjugated Linoleic Acid
Koichiro OHNUKI, Satoshi HARAMIZU, Kengo ISHIHARA, and Tohru FUSHIKI† p.2200
Modulation of Cytochrome P4501-mediated Bioactivation of Benzo<Oh>[<Wa>a<Oh>]<Wa>pyreneby
Volatile Allyl Sulfides in Human Hepatoma Cells
Hyang Sook CHUN,† Hyun Jung KIM, and Eun Hye CHOI p.2205
Purification and Characterization of a O-Methyltransferase Capable
of Methylating 2-Hydroxy-3-alkylpyrazine from Vitis vinifera
L. (cv. Cabernet Sauvignon)
Katsumi HASHIZUME,1,† Kazuyuki TOZAWA,1 Yoshikazu HIRAGA,2 and Isao ARAMAKI1
p.2213
Transfer of Soy Isoflavone into the Egg Yolk of Chickens
Sanshiroh SAITOH, Toshiro SATO, Hiroshi HARADA,＊,† and Toshichika TAKITA＊
p.2220
A Novel Membrane Protein Complex on the Endoplasmic Reticulum
and Early Golgi Compartments in the Yeast Saccharomyces cerevisiae††
Jung-Hwa CHO, Yoichi NODA, Hiroyuki ADACHI, and Koji YODA† p.2226
Catalytic Function of the Residues of Phenylalanine
and Tyrosine Conserved in Squalene-Hopene Cyclases
Tsutomu SATO and Tsutomu HOSHINO† p.2233
Cysteine Proteinase Gene Expression in the Endosperm
of Germinating Carrot Seeds
Chiyoko SAKUTA, Atsushi ODA, Minoru KONISHI, Seiyei YAMAKAWA,
Hiroshi KAMADA, and Shinobu SATOH p.2243
Analysis of Structural Components and Molecular Construction of Soybean
Soluble Polysaccharides by Stepwise Enzymatic Degradation
Akihiro NAKAMURA, Hitoshi FURUTA, Hirokazu MAEDA, Yasunori NAGAMATSU＊,
and Akihiro YOSHIMOTO＊ p.2249
Protein Engineering of Novel Proteinase Inhibitors and Their Effects
on the Growth of Spodoptera exigua Larvae
Hideko INANAGA,1 Daiki KOBAYASI,1 Yoshiaki KOUZUMA,1 Chisa AOKI-YASUNAGA,2
Kazuhiro IIYAMA,2 and Makoto KIMURA1,† p.2259
Glycolic Acid Production Using Ethylene Glycol-Oxidizing Microorganisms
Michihiko KATAOKA,† Mi<Oh><0225><Wa>e SASAKI, Aklani-Rose
G. D. HIDALGO,
Michiko NAKANO, and Sakayu SHIMIZU p.2265
Sorbicillinol, a Key Intermediate of Bisorbicillinoid Biosynthesis
in Trichoderma sp. USF-2690
Naoki ABE,† Osamu SUGIMOTO, Tadaharu ARAKAWA, Ken-ichi TANJI, and Akira HIROTA
p.2271
Note
Molecular Characterization of β-tubulin gene from Pleurotus sajor-caju
Beom-Gi KIM, Young-Bok YOO, Suk-Tae KWON,＊ and Yumi MAGAE＊＊ p.2280
Note
Effects of Seasoning and Heating Device on Mutagenicity
and Heterocyclic Amines in Cooked Beef
Yeun Suk GU,1,† In Soo KIM,2 Jae Hong PARK,1 Seung Han LEE,1 Douck Choun PARK,1
Dong Min YEUM,3 Cheong Il JI,1 Sang Ho KIM,1 Keiji WAKABAYASHI,4 and Seon Bong
KIM1
p.2284
Note
Dehydroascorbic Acid Reduction in Several Tissues
and Cultured Hepatocytes of the Chicken
Keisuke SASAKI,＊,† Yasunari KITAGUCHI,＊＊ Kengo KOGA,＊＊ Rei NARITA,＊＊
Tatsuki FUKUDA,＊＊ and Yosuke AOYAGI＊＊ p.2288
Note
Comparison of Three Signals for Secretory Expression
of Recombinant Human Midkine in Pichia pastoris
Akira MURASUGI† and Yumiko TOHMA-AIBA p.2291
Note
Anti-stress and Anti-fatigue Effects of Fermented Rice Bran
Kyung Mi KIM,1 Kwang Won YU,2 Duk Ho KANG,3 Jong Ho KOH,4
Bum Shik HONG,5 and Hyung Joo SUH6,† p.2294
Note
The Long Terminal Repeat (LTR) Sequence of marY1, a Retroelement
from the Ectomycorrhizal Homobasidiomycete Tricholoma matsutake,
is Highly Conserved in Various Higher Fungi
Hitoshi MURATA, Yasumasa MIYAZAKI, and Katsuhiko BABASAKI p.2297
Note
marY2N, a LINE-Like Non-Long Terminal Repeat (Non-LTR) Retroelement
from the Ectomycorrhizal Homobasidiomycete Tricholoma matsutake
Hitoshi MURATA,1 Yasumasa MIYAZAKI,1 and Akiyoshi YAMADA2 p.2301
Note
Antibacterial Agents that Inhibit Histidine Protein Kinase YycG
of Bacillus subtilis
Kaneyoshi YAMAMOTO,1 Takashi KITAYAMA,1 Shu MINAGAWA,1 Takafumi WATANABE,1
Seiji SAWADA,2 Tadashi OKAMOTO,1 and Ryutaro UTSUMI1† p.2306
Note
Isolation and Identification of Antheridiogens in the Ferns, Lygodium microphyllum
and Lygodium reticulatum
Masami KURUMATANI,1,2 Ken YAGI,1 Takashi MURATA,3,† Meguru TEZUKA,2
Lewis N. MANDER,4 Makoto NISHIYAMA,1 and Hisakazu YAMANE1,†† p.2311
Note
Structural Elucidation and Synthesis of 3-Hydroxybenzene-1,2-dicarbaldehyde
from Astigmatid Mites†
Tomoyo SAKATA and Yasumasa KUWAHARA†† p.2315
Note
Hypoglycemic Effect of a Hot-water Extract from Defatted Sesame
(Sesamum indicum L.) Seed on the Blood Glucose Level
in Genetically Diabetic KK-Ay Mice
Hisanao TAKEUCHI,† Lau Yan MOOI, Yoko INAGAKI, and Puming HE p.2318
Note
Chemical Synthesis and Biological Activity of The Gelatinase Biosynthesis-
Activating Pheromone of Enterococcus faecalis and Its Analogs
Jiro NAKAYAMA,†,†† Yong CAO, Takaaki HORII, Shohei SAKUDA, and Hiromichi NAGASAWA
p.2322
Note
Lactobacillus casei NY1301 Increases the Adhesion of Lactobacillus gasseri
NY0509 to Human Intestinal Caco-2 Cells
Yukimasa AZUMA and Manabu SATO p.2326
Note
Isolation and Some Characterization of an Acidic Polysaccharide
with Anti-calcification Activity from Coccoliths of a Marine Alga,
Pleurochrysis carterae
Noriaki OZAKI, Shohei SAKUDA, and Hiromichi NAGASAWA† p.2330
Note
Screening for Phenoloxidases from Edible Mushrooms
Kohei MORISAKI,1 Tsutomu FUSHIMI,2 Satoshi KANEKO,2 Isao KUSAKABE,1
and Hideyuki KOBAYASHI2† p.2334
Note
Apoptosis induced by Picolinic Acid-related Compounds in HL-60 Cells
Shin OGATA, Kazuko INOUE, Keiko IWATA, Katsuzumi OKUMURA, and Hiroshi TAGUCHI†
p.2337
Note
No Factors Except for the Hap Complex increase the Taka-amylase A Gene
Expression by Binding to the CCAAT Sequence in the Promoter Region
Masashi KATO,† Fumiko NARUSE, Tetsuo KOBAYASHI, and Norihiro TSUKAGOSHI p.2340
Note
Characterization of Nucleoside Diphosphate Kinase
from Moderately Halophilic Eubacteria
Yasushi YONEZAWA, Hiroko TOKUNAGA, Matsujiro ISHIBASHI, and Masao TOKUNAGA†
p.2343
Note
Genetic Analysis of the His-to-Asp Phosphorelay Implicated
in Mitotic Cell Cycle Control: Involvement of Histidine-Kinase Genes
of Schizosaccharomyces pombe
Keisuke AOYAMA, Hirofumi AIBA,† and Takeshi MIZUNO p.2347
Note
Purification and Some Properties of an Inhibitor for a Yeast Pleiotropic
Drug Resistant Pump from Kitasatospora sp. E-420
Anoja WANIGASEKERA, Kazumi HIRAGA,† Nobuyuki HAMANAKA,＊ and Kohei ODA p.2353
Note
Antimutagenic Activity against Trp-P-1 of the Edible Thai Plant,
Oroxylum indicum Vent.
Kazuhiko NAKAHARA,† Mayumi ONISHI-KAMEYAMA,1 Hiroshi ONO,1
Mitsuru YOSHIDA,1 and Gassinee TRAKOONTIVAKORN2 p.2358
Note
Appearance of Poor-fermenting Variants in Brewing Yeast Culture
Hiromi YAMAGISHI,1 Toshifumi YUUKI,1 Noboru KAGAMI,1 Yukitomo YOKOGAWA,1
Kazunori SHIBATA,1 Masayo MINEMURA,2 and Yoshikazu OHYA2 p.2361
Note
Characterization of the RcsC→YojN→RcsB Phosphorelay Signaling
Pathway Involved in Capsular Synthesis in Escherichia coli
Mian Hua CHEN, Shin-ichiro TAKEDA, Hisami YAMADA, Yuko ISHII,
Takafumi YAMASHINO, and Takeshi MIZUNO† p.2364
-1-
Structure of Green Pigment Formed by the Reaction of Caffeic Acid Esters
(or Chlorogenic acid) with a Primary Amino Compound
Goro YABUTA, Yukimichi KOIZUMI, Kazuko NAMIKI,1 Mitsuhiko HIDA,2 and Mitsuo NAMIKI3
Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture,
1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
1Sugiyama Jogakuen University, (Current address: 2-175 Yashirodai, Meitou-ku, Nagoya 465-0092, Japan)
2Tokyo Metropolitan University, (Current address: 7-2-12 Minamikoiwa, Edogawa-ku, Tokyo 133-0056, Japan)
3Nagoya University, (Current address: 2-175 Yashirodai, Meitou-ku, Nagoya 465-0092, Japan)
Received April 26, 2000; Accepted June 20, 2001
A marked greening observed in some foods such as sweet potato, burdock, and others during food processing was shown to be due to green pigment formation by the condensation reaction of two molecules of chlorogenic acid or caffeic acid ester with one molecule of a primary amino compound under aeration in alkaline solution. Reduction of the green pigment by ascorbic acid or NaBH4 gave a yellow product, which readily turn green and then blue in air. The reduced and acetylated product of the green pigment was identified to be a novel trihydroxy benzacridine derivative, and the yellowish ethanol solution of this product immediately turned green upon addition of butyl amine or diluted alkali. Therefore, the green pigment was assumed to be an oxidized quinone type product of trihydroxy benzacridine. This identification of the structure was supported by the correspondence of the measured absorption spectra with those calculated by the molecular orbital method. A possible charge transfer complex between products of different oxidation steps in green solution was proposed.
Key words: green pigment; chlorogenic acid; caffeic acid ester; amino compound; benzacridine derivative
-2-
Development of Free Radical Products during the Greening Reaction
of Caffeic Acid Esters (or Chlorogenic Acid) and a Primary Amino Compound
Mitsuo NAMIKI,1 Goro YABUTA, Yukimichi KOIZUMI, and Midori YANO2
Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture,
1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
1Nagoya University (Current address: 2-175 Yashirodai, Meitou-ku, Nagoya 465-0092, Japan)
2Teikyo College 6-31-1 Honnmachi, Sibuya-Ku, Tokyo 151-0071, Japan
Received April 26, 2000; Accepted June 20, 2001
ESR spectra were measured directly on a marked greening reaction mixture of Et-caffeate and a primary amino compound in alkali solution under aeration. A clear hyperfine structure was commonly detected early in the greening reaction with different amino compounds. Its hyperfine spectrum split into seven peaks was analyzed and found to be due to the oxidized free radical product of the Et-caffeate using an authentic sample system.
Another type of hyperfine ESR spectrum was observed later in the reaction, and was altered with different amino compounds. The hyperfine structure for n-butylamine split into12 lines. The latter type of free radical products were assumed to be a semiquinone type radical compound of the trihydroxy benzacridine derivative, which was identified as the principal structure of the green and yellow pigments formed by this greening reaction system. A formation mechanism of the green pigment and related products involving these free radical products is proposed.
Key words: green pigment; caffeic acid ester; amino compound; ESR; free radical
-3-
Effects of Rooibos Tea Extract on Antigen-specific Antibody Production
and Cytokine Generation in Vitro and in Vivo
Kazuyoshi KUNISHIRO, Akihiro TAI, and Itaru YAMAMOTO†
Department of Immunochemistry, Faculty of Pharmaceutical Sciences, Okayama University,
Tsusima-naka 1-1-1, Okayama 700-8530, Japan
Received November 20, 2000; Accepted June 8, 2001
Rooibos tea contains a large amount of flavonoids and acts as a potent antioxidant. In this study, we examined the effects of Rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo. The primary in vitro anti-ovalbumin (anti-OVA) or sheep red blood cell (SRBC) antibody production in murine splenocytes was markedly stimulated by the addition of the tea extract at concentrations of 1--100 μg/ml. On the other hand, a nonspecific antibody response elicited with lipopolysaccharide (LPS) in purified splenic B-cells was not modified by the extract. Rooibos tea extract caused an increase in the generation of interleukin 2 (IL-2) both in OVA- and anti-CD3-primed splenocytes at concentrations ranging from 10 μg/ml to 1000 μg/ml. In contrast, this tea extract suppressed the generation of interleukin 4 (IL-4) in OVA-primed splenocytes. Moreover, the reduction of OVA-induced antibody production in serum of the cyclosporin A (CyA) -treated rats can be significantly restored and the IL-2 generation in murine splenocytes was stimulated, following oral administrations of Rooibos tea extract. Thus, our findings suggested that Rooibos tea extract may facilitate the antigen-specific antibody production through selective augmentation of IL-2 generation both in vitro and in vivo. Collectively, Rooibos tea intake may be of value in prophylaxis of the diseases involving a severe defect in Th1 immune response such as cancer, allergy, AIDS, and other infections.
Key words: Rooibos tea; antibody production; IL-2 generation; murine splenocytes
-4-
Regulation by Two CatR Proteins that Differ in Binding Affinity
to catB Promoters Expressing Two cat Gene Clusters
Atsushi TAKASHIMA,1 Shuichiro MURAKAMI,2 Shinji TAKENAKA,2 and Kenji AOKI2,†
Division of Bioscience, The Graduate School of Science and Technology1 and Laboratory
of Applied Microbiology, Department of Biofunctional Chemistry, Faculty of Agriculture2,
Kobe University, Rokko, Kobe 657-8501, Japan
Received December 4, 2000; Accepted February 19, 2001
We isolated the two LysR-type regulatory proteins CatR1 and CatR2, which regulate the expression of cat1 and cat2 gene clusters, respectively, required for catechol degradation in the bacterium Frateuria sp. ANA-18. In a gel mobility shift assay using CatR1 and the DNA fragment containing the catB1 promoter region, the formation of two complexes, complex 1-1 (C1-1) and complex 1-2 (C1-2), was observed in the presence of cis,cis-muconate. On the other hand, CatR2 and the DNA fragment containing the catB2 promoter region formed only complex 2-2 (C2-2) at a lower concentration of cis,cis-muconate than that at which C1-1 and C1-2 were formed. As the concentration of cis,cis-muconate decreased, the production of the muconate cycloisomerase isozyme MC II encoded by catB2 decreased as well as that of MC I encoded by catB1. However, the amount of MC II synthesized was larger than that of MC I at low concentrations. On the basis of these results, we concluded that the catB2 promoter was activated at low concentrations of cis,cis-muconate.
Key words: CatR; catB; cis,cis-muconate; muconate cycloisomerase; aniline-assimilating bacterium
-5-
Influence of Adenine-induced Renal Failure on Tryptophan-niacin
Metabolism in Rats
Tsutomu FUKUWATARI,† Yuko MORIKAWA, Fumiko HAYAKAWA,
Etsuro SUGIMOTO, and Katsumi SHIBATA
Course of Food Science and Nutrition, Department of Life Style Studies, School of Human Cultures,
The University of Shiga Prefecture, Hikone, Shiga 522-8533, Japan
Received January 24, 2001; Accepted May 30, 2001
To discover the role of the kidney in tryptophan degradation, especially tryptophan to niacin, rat kidneys were injured by feeding a diet containing a large amount of adenine. The kidney contains very high activity of aminocarboxymuconate-semialdehyde decarboxylase (ACMSD), which leads tryptophan into the glutaric acid pathway and then the TCA cycle, but not to the niacin pathway. On the other hand, kidneys contain significant activity of quinolinate phosphoribosyltransferase (QPRT), which leads tryptophan into the niacin pathway. The ACMSD activity in kidneys were significantly lower in the adenine group than in the control group, while the QPRT activity was almost the same, however, the formations of niacin and its compounds such as N1-methylnicotinamide and its pyridones did not increase, and therefore, the conversion ratio of tryptophan to niacin was lower in the adenine group than in the control group. The contents of NAD and NADP in liver, kidney, and blood were also lower in the adenine group. The decreased levels of niacin and the related compounds were consistent with the changes in the enzyme activities involved in the tryptophan-niacin metabolism in liver. It was concluded from these results that the conversion of tryptophan to niacin is due to only the liver enzymes and that the role of the kidney would be extremely low.
Key words: renal deficiency; tryptophan metabolism; nicotinamide; conversion ratio of tryptophan to niacin; aminocarboxymuconate-semialdehyde decarboxylase
-6-
Superoxide- and 1,1-Diphenyl-2-picrylhydrazyl Radical-scavenging Activities
of Soyasaponin β g Related to Gallic Acid
Yumiko YOSHIKI,1,＊ Takashi KAHARA,1 Kazuyoshi OKUBO,1 Terumi SAKABE,2
and Terumasa YAMASAKI2
1Department of Environmental Bioremediation, Graduate School of Agriculture, Tohoku University,
1-1 Tsutsumidori Amamiyamachi, Aobaku, Sendai, Miyagi 981-8555, Japan
2Fundamental Technology Center, Asahi Chemical Ind. Co. Ltd., 2-1 Samejima, Fuji, Shizuoka 416-0934,
Japan
Received February 7, 2001; Accepted June 11, 2001
Soyasaponin β g at 1 mM had 8％ scavenging activity for O<Oh>_<Wa>{2}＾{<Oh>-<Wa>}, and 25 μM β g scavenged 20.9％ for the DPPH radical (IC<Oh>_<Wa>{50}: 63.8 μM). In the soyasaponin β g-gallic acid system, synerigistic effects were observed at a low level of gallic acid concentration. The spin density distribution calculated by the MNDO/AM1 method showed unpaired electron localization on the carbons at C-4 and C-6, and on the ketone group at C-4 of the DDMP moiety. Furthermore, for soyasaponin β g, the MNDO/AM1 method gave an ionization potential of 8.38 eV, electron affinity of 1.16 eV and Mulliken electronegativity of 4.77 eV. Based on this evidence, the synergistic antiradical effects of the soyasaponin β g-gallic acid system are assumed to involve two-electron reduction from gallic acid.
Key words: superoxide; 1,1-diphenyl-2-picrylhydrazyl radical; soyasaponin β g; triterpenoid; Leguminosae
-7-
Orotic Acid Added to Casein, but not to Egg Protein, Soy Protein,
or Wheat Gluten Diets Increases 1,2-Diacylglycerol Levels and Lowers
Superoxide Dismutase Activities in Rat Liver
Yoritaka AOYAMA,† Mizuho WADA, and Masashi MORIFUJI
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University,
Nishi-9, Kita-9, Kita-ku, Sapporo 060-8589, Japan
Received February 13, 2001; Accepted June 22, 2001
Effects of the dietary addition of orotic acid to a diet containing casein as a sole protein source on lipid levels in the liver and serum, activities of antioxidant enzymes in the liver, and some enzyme activities in serum, were compared with other diets containing egg protein, soy protein, or wheat gluten, respectively.
1. The contents in the liver of each lipid were increased by the addition of orotic acid as compared with those values without it. The orotic acid added to the casein diet caused accumulation of more liver total lipids, triacylglycerol, 1,2-diacylglycerol, and phospholipids than those fed three other diets.
2. The addition of orotic acid to the casein, but not to the other three diets, lowered the activities of liver superoxide dismutase and increased the activities of both serum ornithine carbamoyltransferase and alanine aminotransferase.
Thus, the significant increase in serum ornithine carbamoyltransferase activities as the marker of liver lesions may result from the marked accumulation of liver lipids, decreased activities of hepatic superoxide dismutase, and the increased level of hepatic 1,2-diacylglycerol, followed by possibly the increased level of superoxide anion and increased activity of protein kinase C in rats fed the casein diet with orotic acid added.
Key words: orotic acid; dietary casein; 1,2-diacylglycerol; ornithine carbamoyltransferase; superoxide dismutase
-8-
Phosphoglucose Isomerase from Bananas: Partial Characterization and
Relation to Main Changes in Carbohydrate Composition during Ripening
Beatriz Rosana CORDENUNSI, Jo<Oh><0227><Wa>ao Roberto Oliveira do NASCIMENTO,
Renata Vieira da MOTA, and Franco Maria LAJOLO†
Department of Food Science and Experimental Nutrition, College of Pharmaceutical Sciences,
University of S<Oh><0227><Wa>ao Paulo, Av. Lineu Prestes 580, Bloco 14, CEP 05508-900, S<Oh><0227><Wa>ao Paulo-SP, Brasil
Received February 14, 2001; Accepted June 21, 2001
Some characteristics of phosphoglucose isomerase (PGI, EC 5.3.1.9) from banana were measured during fruit ripening of three banana cultivars. In banana, PGI was present as two dimeric isoenzymes, named PGI1 and PGI2, which had similar native molecular masses but differed in relation to heat stability and isoelectric point. Total PGI activity showed a distinct two-step change during fruit ripening. Before the climacteric period, PGI activity gradually decreased with the starch content, then its activity began to increase with sucrose accumulation. The ratio of PGI1, and PGI2 was constant, indicating that both enzymes would be involved in starch degradation and sucrose synthesis. PGI activity and changes in carbohydrate composition suggests the existence of some control to fit the requirements of the intense carbon flow from starch to sucrose.
Key words: phosphoglucose isomerase; banana; ripening; starch
-9-
Supplemental Silk Protein, Sericin, Suppresses Colon Tumorigenesis
in 1,2-Dimethylhydrazine-Treated Mice by Reducing Oxidative Stress
and Cell Proliferation
Siqin ZHAORIGETU,＊ Masahiro SASAKI,＃ Hiromitsu WATANABE,＊＊ and Norihisa KATO＊
＊Faculty of Applied Biochemistry, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
＊＊Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan
＃Seiren Co., Ltd., 10-1 Keya 1-Chome, Fukui 918-8560, JapanReceived March 8, 2001; Accepted June 22, 2001
This study was done to discover the underlying mechanism of the inhibitory effect of sericin against colon tumorigenesis. Mice were fed a diet with 30 g/kg sericin for 115 d, and given a weekly injection of 1,2-dimethylhydrazine (10 mg/kg body weight) for the initial 10 wk. Dietary supplemental sericin caused a 62％ reduction in the incidence of colonic adenoma (P＜0.05), but did not affect the incidence of colonic adenocarcinoma. Sericin intake significantly reduced the number of colon adenomas. Consumption of sericin significantly reduced the BrdU labeling index of colonic proliferating cells and the expression of colonic c-myc and c-fos. The levels of colonic 8-hydroxydeoxyguanosine, 4-hydroxynonenal, and inducible nitric oxide synthase protein were significantly suppressed by sericin. The results suggest that dietary sericin suppresses the development of colon tumors by reducing oxidative stress, cell proliferation, and nitric oxide production.
Key words: sericin; colon tumorigenesis; cell proliferation; oxidative stress; nitric oxide
-10-
Characterization of The Cellulose-Binding Ability of Geotrichum sp. M111
Cells and Its Application to Dehydration of The Distilled Waste
of Sweet Potato Shouchu
Hidefumi YOSHII,† Takeshi FURUTA, Miyuki IKEDA, Takatoki ITO,
Haruyuki IEFUJI,＊ and Pekka LINKO＊＊
Dept. of Biotechnology, Tottori University, Tottori 680-8552, Japan
＊Lab. of Environmental Technology, National Research Institute of Brewing,
Higashi Hiroshima 739-0046, Japan
＊＊Dept. of Chemical Technology, Helsinki University of Technology, FIN-02015, P.O. Box 6100 HUT,
(Espoo) Finland
Received March 9, 2001; Accepted May 28, 2001
The cellulose-binding ability of Geotrichum sp. M111 cells was investigated by the micro-tube method which gives an indication of the binding ability of M111 cells. The optimum pH value and temperature were 3--7 and below 50°C, respectively, from measurement of the aggregation height for a mixture of cellulose powder and M111 cells. The binding constant of 0.3％ for M111 cells to cellulose powder was obtained in a 20 mM citrate buffer of pH 5.0 at 30°C. Aggregation was inhibited by such surfactants as sodium dodecylsulfate. The binding ability of M111 cells to cellulose fiber disappeared after a treatment with Driselase or Pronase E. This suggests that the binding ability might be related to the cell surface proteins. The dehydration rate of the distilled waste of sweet potato shouchu was accelerated by the addition of M111 cells. The analysis of dehydration by a linear viscoelastic model suggests that the acceleration effect might have been due to the space increase between cellulose fibers with the cell addition.
Key words: shouchu waste; dehydration; cellulose-binding cell
-11-
Chemistry of Zerumbone. 2. Regulation of Ring Bond Cleavage
and Unique Antibacterial Activities of Zerumbone Derivatives
Takashi KITAYAMA,1,† Kaneyoshi YAMAMOTO,1 Ryutaro UTSUMI,1 Masahiro TAKATANI,1
Richard K. HILL,2 Yasushi KAWAI,3 Seiji SAWADA,4 and Tadashi OKAMOTO1
1Department of Agricultural Chemistry, Faculty of Agriculture, Kinki University, Nara 631-8505, Japan
2Department of Chemistry, University of Georgia, Athens, Georgia 30602, U.S.A.
3Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
4Kyoto University of Education, Fushimi, Kyoto 612-0863, Japan
Received March 13, 2001; Accepted May 11, 2001
Further investigation of the chemistry of the eleven-membered cyclic sesquiterpene, zerumbone, the major component of the wild ginger, Zingiber zerumbet Smith, has revealed a new selective epoxidation process, a further example of a novel Favorskii-initiated double ring contraction, and a regiospecific fragmentation of zerumbone dibromide derivatives. Several zerumbone derivatives were found to be selective inhibitors of the growth of Gram-positive bacteria.
Key words: zerumbone; ring cleavage; antibacterial activity; histidine protein kinase; two-component system
-12-
Increased Energy Metabolism and Suppressed Body Fat Accumulation
in Mice by a Low Concentration of Conjugated Linoleic Acid
Koichiro OHNUKI, Satoshi HARAMIZU, Kengo ISHIHARA, and Tohru FUSHIKI†
Laboratory of Nutritional Chemistry, Department of Applied Life Sciences, Graduate School of Agriculture,
Kyoto University, Kyoto 606-8502 Japan
Received March 15, 2001; Accepted May 22, 2001
We investigated the dose-effect of the long-term intake of conjugated linoleic acid (CLA) on the energy metabolism and fat accumulation in mice. Five-week-old male Std ddY mice were fed on a diet containing none (control), 0.25％, 0.5％ or 1.0％ CLA for 4 or 8 weeks. The body weight was lower in the CLA groups than in the control group, and significant differences were detected between the 1.0％ CLA group and the control group at both 4 and 8 weeks. The epididymal and perirenal adipose tissue weights were significantly lower in the CLA groups than in the control group. The liver weight and hepatic triglyceride values were higher in the 1.0％ CLA group than in the other groups. The metabolic rate was measured after 8 weeks by using a gas analyzer. The oxygen consumption of the mice in the CLA groups was significantly higher than that of the control mice. Since there was a significant effect on the mice supplemented with 0.25％ CLA, low concentration of CLA is suggested to suppress the body fat accumulation and increase the energy metabolism.
Key words: conjugated linoleic acid; mouse; energy metabolism; body fat accumulation
-13-
Modulation of Cytochrome P4501-mediated Bioactivation of Benzo<Oh>[<Wa>a<Oh>]<Wa>pyrene
by Volatile Allyl Sulfides in Human Hepatoma Cells
Hyang Sook CHUN,† Hyun Jung KIM, and Eun Hye CHOI
Korea Food Research Institute, Sungnam 463-746, Korea
Received March 30, 2001; Accepted June 25, 2001
Allyl sulfides such as diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS), typical flavor components of Allium vegetables, have been shown to inhibit benzo<Oh>[<Wa>a<Oh>]<Wa>pyrene (B<Oh>[<Wa>a<Oh>]<Wa>P)-induced carcinogenesis in animal models. As a possible mechanism of this inhibition, the effect of these volatile substances on cytochrome P450 (CYP)1 (CYP1A1, 1A2 and 1B1)-mediated bioactivation of B<Oh>[<Wa>a<Oh>]<Wa>P was investigated using a human hepatoma cell model (HepG2). DADS and DATS inhibited the B<Oh>[<Wa>a<Oh>]<Wa>P-induced ethoxyresorufin O-deethylase (EROD) activity, a marker enzyme for CYP1, by 30--90％ and 70--95％ at 100--1,000 μM concentration, respectively. The cell viability, an indicator of the capacity to inhibit B<Oh>[<Wa>a<Oh>]<Wa>P bioactivation, was increased by treatments of 100--1,000 μM DADS and 10--100 μM DATS. Immunoblot results indicated that the B<Oh>[<Wa>a<Oh>]<Wa>P inducible CYP1A2 protein was suppressed by 100--1,000 μM of DADS and 10--100 μM of DATS, but CYP1A1 and 1B1 were not detectable in any microsomes. Analysis of B<Oh>[<Wa>a<Oh>]<Wa>P metabolites revealed that the level of 7,8-diol formed was significantly reduced in the DADS and DATS treated microsomes as compared to the control. The level of 9,10-diol and 4,5-diol formed was also lowered by the allyl sulfide treatments. These results suggest that the protective mechanism of allyl sulfides on B<Oh>[<Wa>a<Oh>]<Wa>P-induced carcinogenesis is possibly related with the modulation of CYP1-mediated bioactivation of B<Oh>[<Wa>a<Oh>]<Wa>P.
Key words: Allyl sulfides; benzo<Oh>[<Wa>a<Oh>]<Wa>pyrene; CYP1; HepG2
-14-
Purification and Characterization of a O-Methyltransferase Capable
of Methylating 2-Hydroxy-3-alkylpyrazine from Vitis vinifera
L. (cv. Cabernet Sauvignon)
Katsumi HASHIZUME,1,† Kazuyuki TOZAWA,1 Yoshikazu HIRAGA,2 and Isao ARAMAKI1
1National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashihiroshima 739-0046, Japan
2Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama,
Higashihiroshima 739-8526, Japan
Received March 30, 2001; Accepted June 19, 2001
An S-adenosyl-L-methionine-dependent O-methyltransferase capable of methylating 2-hydroxy-3-alkylpyrazine (HP) was purified 7,300-fold to apparent homogeneity with an 8.2％ overall recovery from Vitis vinifera L. (cv. Cabernet Sauvignon) through a purification procedure including column chromatography on DEAE-Sepharose FF, Ether-5PW, hydroxyapatite, G2000SWXL, and DEAE-5PW. The relative molecular mass of the native enzyme estimated on gel permeation chromatography was 85 kDa, and the subunit molecular mass was estimated to be 41 kDa on SDS-polyacrylamide gel electrophoresis. The enzyme also methylates caffeic acid. The Vmax for IBHP and caffeic acid were 0.73 and 175 pkatals/mg, respectively, and the respective Km for IBHP and caffeic acid were 0.30 and 0.032 mM. The optimum pH for IBHP (8.5) was different from that for caffeic acid (7.5).
Key words: O-methyltransferase; Vitis vinifera; hydroxypyrazine; methoxypyrazine
-15-
Transfer of Soy Isoflavone into the Egg Yolk of Chickens
Sanshiroh SAITOH, Toshiro SATO, Hiroshi HARADA,＊,† and Toshichika TAKITA＊
Food Research ＆ Development Laboratories, Honen Corporation, Shinminato 2, Shimizu,
Shizuoka 424-0824, Japan
＊Department of Nutritional Science, Faculty of Applied Biological Science, Tokyo University of Agriculture,
Tokyo 156-8502, Japan
Received April 2, 2001; Accepted June 15, 2001
A diet containing a high concentration of soy isoflavone was administered to laying hens and the contents of the isoflavones transferred to the plasma and egg yolk were measured. A method for quantitatively measuring the concentration of isoflavone in the yolk was first established, before a high concentration of soy isoflavone was administered to the laying hens over an 18-day period. The concentrations of isoflavone in the plasma and egg yolk reached their highest on the 12th day of the feeding period, the values being 3,167 nmol/l and 65.29 μg/100 g, respectively. The concentration of cholesterol in the yolk was slightly affected during the early stages of the feeding period. These findings clearly demonstrate that soy isoflavone was transferred into the yolk from the feed and that the cholesterol concentration in the yolk was affected by administering the soy isoflavone-enriched feed.
Key words: isoflavone; egg; cholesterol; genistein; hypocotyl
-16-
A Novel Membrane Protein Complex on the Endoplasmic Reticulum
and Early Golgi Compartments in the Yeast Saccharomyces cerevisiae††
Jung-Hwa CHO, Yoichi NODA, Hiroyuki ADACHI, and Koji YODA†
Department of Biotechnology, the University of Tokyo, Yayoi, Bunkyo-Ku, Tokyo 113-8657, Japan
Received April 3, 2001; Accepted June 7, 2001
A novel membrane protein, Yml067c in the systematic ORF name, was discovered as a component of immunoisolated vesicles of the early Golgi compartment of the yeast Saccharomyces cerevisiae (Cho et al., FEBS Lett. 469, 151--154 (2000)). Conserved sequences having sequence similarity to Yml067c were widely distributed in the eukaryotes and one of them, Yal042w, was found in the Saccharomyces genome database. In the yeast cell, Yml067c and Yal042w were found to form a heterooligomeric complex by immunoprecipitation of their tagged derivatives from the detergent-solubilized membrane. Cell fractionation and indirect immunofluorescent staining indicated that the majority of these proteins were localized on the ER membrane. Therefore, the Yml067c-Yal042w complex should shuttle between the ER and the early Golgi compartment as well as the p24-family proteins.
Key words: yeast; endoplasmic reticulum (ER); Golgi compartment; Sed5 vesicle
-17-
Catalytic Function of the Residues of Phenylalanine
and Tyrosine Conserved in Squalene-Hopene Cyclases
Tsutomu SATO and Tsutomu HOSHINO†
Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School
of Science and Technology, Niigata University, Ikarashi, Niigata 950-2181, Japan
Received April 9, 2001; Accepted May 18, 2001
Site-directed mutagenesis experiments on all the conserved residues of Phe and Tyr in all the known squalene-hopene cyclases (SHCs) were carried out to identify the active site residues of thermophilic Alicyclobacillus acidocaldarius SHC. The following functions are proposed on the basis of kinetic data and trapping of the prematurely cyclized products: (1) The Y495 residue probably amplifies the D376 acidity, which is assumed to work as a proton donor for initiating the polycyclization cascade, but its role is moderate. (2) Y609 possibly assists the function of F365, which has previously been assigned to exclusively stabilize the C-8 carbocation intermediate through cation-π interaction. The Y609A mutant produced a partially cyclized bicyclic triterpene. (3) Y612 works to stabilize both the C10 and C8 carbocations, this being verified by the finding that mono- and bicyclic products were formed with the Y612A mutant. (4) F129 was first identified to play a crucial role in catalysis. (5) The three residues, Y372, Y474 and Y540, are responsible for reinforcing the protein structure against thermal denaturation, Y474 being located inside QW motif 3.
Key words: squalene; hopene; triterpene; terpene cyclase; Alicyclobacillus acidocaldarius
-18-
Cysteine Proteinase Gene Expression in the Endosperm
of Germinating Carrot Seeds
Chiyoko SAKUTA, Atsushi ODA, Minoru KONISHI, Seiyei YAMAKAWA,
Hiroshi KAMADA, and Shinobu SATOH
Institute of Biological Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
Received April 12, 2001; Accepted June 15, 2001
A gene for carrot seed cysteine proteinase (CSCP; AB057371, AB057372) was cloned using PCR. The deduced amino acid sequence of CSCP had active sites for eukaryotic cysteine proteinases, putative signal sequences, and an endoplasmic reticulum targeting sequence. RNA gel blot analysis showed that CSCP transcripts appeared from dry seed, reached a maximum 3 days after imbibition (DAI), and disappeared by 5 DAI. In situ hybridization showed that CSCP transcripts accumulated in the endosperm of germinating seeds. This is the first report of the expression pattern of a cysteine proteinase gene in the endosperm of germinating dicotyledonous plants. The promoter of the CSCP gene had an endosperm motif and many other motifs also found in the promoters of endosperm-specific storage protein genes in monocotyledons. It is suggested that dicotyledons, like monocotyledons, have a temporal and spatial regulation system for endosperm-specific gene expression in germinating seeds.
Key words: cysteine proteinase; endosperm; carrot seed; cysteine proteinase inhibitor
-19-
Analysis of Structural Components and Molecular Construction of Soybean
Soluble Polysaccharides by Stepwise Enzymatic Degradation
Akihiro NAKAMURA, Hitoshi FURUTA, Hirokazu MAEDA, Yasunori NAGAMATSU＊,
and Akihiro YOSHIMOTO＊
Tsukuba R＆D Center, Fuji Oil Co., Ltd., 4-3 Kinunodai, Yawara, Tsukuba-gun, Ibaraki 300-2497, Japan
＊Department of Applied Biochemistry, Faculty of Applied Biological Science, Hiroshima University,
1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan
Received April 6, 2001; Accepted June 8, 2001
Soybean soluble polysaccharides (SSPS) extracted from soybean cotyledons have a pectin-like structure. The core polysaccharides after treatments with four kinds of hemicellulases and a pectinase contained approximately equal numbers of L-rhamnose and D-galacturonate residues, suggesting the presence of the rhamnogalacturonan (RG) I structure consisting of the diglycosyl repeating unit, -4)-α-D-GalpA-(1→2)-α-L-Rhap-(1-. The lengths of RG chains were calculated as approximately 15, 28, and 100 diglycosyl repeats. The RG components linked to each other by intervention of galacturonan (GN) chains, constituting the backbone of SSPS. All arabinose residues, which constitute 21％ of total SSPS sugars, were found to be in side chains from RG regions, and this was also true for galactose residues, which constitute 50％ of total sugars. Of arabinose residues, 94％ are present as α-1,3- or α-1,5-arabinans, and 89％ of galactose residues were present as β-1,4-galactans. Galactan chains are modified with arabinose, xylose, fucose, and glucose at the sites close to the RG regions.
Key words: soybean; polysaccharides; pectin
-20-
Protein Engineering of Novel Proteinase Inhibitors and Their Effects
on the Growth of Spodoptera exigua Larvae
Hideko INANAGA,1 Daiki KOBAYASI,1 Yoshiaki KOUZUMA,1 Chisa AOKI-YASUNAGA,2
Kazuhiro IIYAMA,2 and Makoto KIMURA1,†
1Laboratory of Biochemisty and 2Institute of Biological Control, Faculty of Agriculture, Graduate School,
Kyushu University, Fukuoka 812-8581, Japan
Received April 18, 2001; Accepted June 1, 2001
Novel types of proteinase inhibitors with multi-inhibitory activities were generated by replacement of phytocystatin domains in sunflower multi-cystatin (SMC) by the serine proteinase inhibitor BGIT from bitter gourd seeds. Two chimeric inhibitors SMC-T3 and SMC-T23, in which the third domain in SMC and the second and third domains in SMC were replaced by BGIT, acquired trypsin inhibitory activity (Ki: 1.46×10＾{<Oh>-<Wa>7} M and 1.75×10＾{<Oh>-<Wa>7} M), retaining inhibitory activity toward papain (Ki: 4.5×10＾{<Oh>-<Wa>8} M and 1.52×10＾{<Oh>-<Wa>7} M), respectively. We compared the chimeric inhibitors and the recombinant SMC (r-SMC) in relation to their effects on the growth of larval Spodoptera exigua. When the second instar larvae were reared on a diet containing rSMC, SMC-T3, or SMC-T23 for ten days, a significant reduction in weight gain was observed. Mean weights for rSMC, SMC-T3, and SMC-T23 were 43 mg, 32 mg, and 43 mg, respectively, as compared with that (60 mg) for the absence of the inhibitor. In contrast, BGIT had little effect on the growth of the S. exigua larvae. This result indicated that the chimeric inhibitor SMC-T3 with two phytocystatin domains and one serine proteinase inhibitor domain is an efficient inhibitor of proteinases in the S. exigua larvae. Therefore, this novel type of proteinase inhibitor with multi-inhibitory activities may represent a promising protein for successful application to a transgenic plant with insect resistance.
Key words: protein engineering; phytocystatin; Spodoptera exigua; sunflower multi-cystatin; trypsin inhibitor
-21-
Glycolic Acid Production Using Ethylene Glycol-Oxidizing Microorganisms
Michihiko KATAOKA,† Mi<Oh><0225><Wa>e SASAKI, Aklani-Rose G. D. HIDALGO,
Michiko NAKANO, and Sakayu SHIMIZU
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku,
Kyoto 606-8502, Japan
Received April 19, 2001; Accepted May 30, 2001
Screening for microorganisms oxidizing ethylene glycol to glycolic acid was carried out. Among stock cultures, several yeasts and acetic acid bacteria showed high glycolic acid producing activity. Pichia naganishii AKU 4267 formed the highest concentration of glycolic acid, 35.3 g/l, from 10％ (v/v) ethylene glycol (molar conversion yield, 26.0％). Among soil isolates, Rhodotorula sp. 3Pr-126, isolated using propylene glycol as a sole carbon source, formed the highest concentration of glycolic acid, 25.1 g/l, from 10％ (v/v) ethylene glycol (molar conversion yield, 18.5％). Rhodotorula sp. 3Pr-126 showed higher activity toward 20％ (v/v) ethylene glycol than P. naganishii AKU 4267.
Optimization of the conditions for glycolic acid production was investigated using P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126. Under the optimized conditions, P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126 formed 105 and 110 g/l of glycolic acid (corrected molar conversion yields, 88.0 and 92.2％) during 120 h of reaction, respectively.
Key words: glycolic acid; ethylene glycol; Pichia naganishii; Rhodotorula sp.
-22-
Sorbicillinol, a Key Intermediate of Bisorbicillinoid Biosynthesis
in Trichoderma sp. USF-2690
Naoki ABE,† Osamu SUGIMOTO, Tadaharu ARAKAWA, Ken-ichi TANJI, and Akira HIROTA
School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan
Received April 23, 2001; Accepted June 6, 2001
In the course of our screening program for free radical scavengers from Trichoderma sp. USF-2690, we found an unidentified metabolite (1) that appeared by the method used for HPLC analysis. Metabolite 1 gradually decreased with the production of bisorbicillinoids and was easily missed during the general isolation procedure. The LC-ESI-MS (negative) analysis for 1 gave m/z 247 as the (M-1)＾{<Oh>-<Wa>} ion peak. The hydrolysis of synthetic 6--O--acetylsorbicillinol (±-2) by 0.05 MKey words: KOH and acetylation of product 1 in an aqueous solution indicated that the structure of 1 was (6S)-4-(2,4-hexadienoyl)-3,6-dihydroxy-2,6-dimethyl-2,4-cyclohexadien-1-one, designated sorbicillinol, a quinol that has been postulated to be important in bisorbicillinoid biosynthesis.
Key words: sorbicillinol; DPPH-radical scavenger; Trichoderma sp. USF-2690; bisorbicillinoids biosynthesis
-23-
Note
Molecular Characterization of β-tubulin gene from Pleurotus sajor-caju
Beom-Gi KIM, Young-Bok YOO, Suk-Tae KWON,＊ and Yumi MAGAE＊＊
Division of Applied Microbiology, National Institute of Agricultural Science and Technology,
Suweon, 441-707, Korea
＊Department of Genetic Engineering, Sung Kyun Kwan University, Suweon, Korea
＊＊Forestry and Forest Products Research Institute, P.O. Box 16, Tsukuba-Norin, Ibaraki 305-8687, Japan
Received November 10, 2000; Accepted June 11, 2001
A β-tubulin gene (TUB1) from the basidiomycete Pleurotus sajor-caju was sequenced. TUB1 encodes a 446-amino-acid protein. The coding region is interrupted by 9 introns, all of which had a 5′-GTRNGT . . . YAG-3′ sequence at the boundaries. Locations of the introns in TUB1 were common between the β-tubulin genes of other basidiomycetes, but not with animals, ascomycetes, or plants. This suggests that the introns were inserted independently into the β-tubulin gene after these divisions had diverged.
Key words: Pleurotus sajor-caju; β-tubulin; intron; basidiomycete
-24-
Note
Effects of Seasoning and Heating Device on Mutagenicity
and Heterocyclic Amines in Cooked Beef
Yeun Suk GU,1,† In Soo KIM,2 Jae Hong PARK,1 Seung Han LEE,1 Douck Choun PARK,1
Dong Min YEUM,3 Cheong Il JI,1 Sang Ho KIM,1 Keiji WAKABAYASHI,4 and Seon Bong KIM1
1Faculty of Food and Biotechnology/Institute of Seafood Science, Pukyong National University,
Pusan 608-737, Korea
2Division of Marine Bioscience/Institute of Marine Industry, Gyeongsang National University, Tongyeong 650-160, Korea
3Department of Food Science and Technology, Yangsan College, Yangsan 626-040, Korea
4Cancer Prevention Division, National Cancer Research Institute, 1-1 Tsukiji 5-chome, Chuo-ku,
Tokyo 104-0045, Japan
Received January 15, 2001; Accepted June 25, 2001
Pan-roasted beef showed a lower mutagenicity after various degrees of cooking than charcoaled one. The high mutagenicity of charcoaled beef was due to the formation of more heterocyclic amines, especially AαC (2-amino-9H-pyrido- <Oh>[<Wa>2,3-b<Oh>]<Wa>indole) and PhIP (2-amino-1-methyl-6-phenylimidazo<Oh>[<Wa>4,5-b<Oh>]<Wa>pyridine) because of rapid and direct heating on the surface of the meat at a high temperature. Seasoning decreased mutagenicity of pan-roasted beef except the very well done sample with unchanged heterocyclic amine contents, but increased mutagenicity of charcoaled beef with decreased levels of AαC and PhIP, probably due to the change of heterocyclic amine precursors or alternatively to the occurrence of other mutagens.
Key words: mutagenicity; heterocyclic amines; AαC; PhIP; MeIQx
-25-
Note
Dehydroascorbic Acid Reduction in Several Tissues
and Cultured Hepatocytes of the Chicken
Keisuke SASAKI,＊,† Yasunari KITAGUCHI,＊＊ Kengo KOGA,＊＊ Rei NARITA,＊＊
Tatsuki FUKUDA,＊＊ and Yosuke AOYAGI＊＊
＊Department of Animal Products, National Institute of Livestock and Grassland Science,
Ibaraki 305-0901, Japan
＊＊Laboratory of Animal Nutrition, Ibaraki University, Ami-machi 300-0393, Ibaraki, Japan
Received February 5, 2001; Accepted May 23, 2001
Dehydroascorbic acid, the oxidized form of ascorbic acid, is rapidly reduced to ascorbate in living organs (ascorbate recycling). We examined the GSH-dependent dehydroascorbate reductase activity in several tissues of the chicken. The activity was highest in the liver, and second highest in the brain. The activity was localized in the cytosol fraction of the liver. We subsequently examined the dehydroascorbate reduction in separated chicken hepatocytes. The cellular ascorbate concentration was elevated in dehydroascorbate-treated cells. It is thought that hepatocytes incorporated external dehydroascorbate and converted it into ascorbate. These findings suggest that the liver plays an important role in ascorbate recycling by the chicken.
Key words: dehydroascorbic acid; chicken; GSH-dependent dehydroascorbic acid reductase; hepatocytes
-26-
Note
Comparison of Three Signals for Secretory Expression
of Recombinant Human Midkine in Pichia pastoris
Akira MURASUGI† and Yumiko TOHMA-AIBA
Meiji Cell Technology Center, Meiji Milk Products Co., Ltd., 540 Naruda, Odawara,
Kanagawa 250-0862, Japan
Received March 7, 2001; Accepted June 6, 2001
The secretion signals of Saccharomyces cerevisiae α mating factor, human midkine itself, and Pichia pastoris acid phosphatase, were tried for the expression of human midkine under the control of the AOX1 gene promoter in P. pastoris. Approximately 28 mg/l, 1.5 mg/l, and 0.2 mg/l of midkine were secreted by using the α mating factor pre-pro-sequence, the midkine signal sequence, and the phosphatase signal sequence in flask cultures, respectively.
Key words: pre-pro-sequence; signal peptide; secretory expression; human midkine; Pichia pastoris
-27-
Note
Anti-stress and Anti-fatigue Effects of Fermented Rice Bran
Kyung Mi KIM,1 Kwang Won YU,2 Duk Ho KANG,3 Jong Ho KOH,4
Bum Shik HONG,5 and Hyung Joo SUH6,†
1School of Food Biotechnology, Woosong University, Daejeon 300-718, Korea
2Department of Kimchi and Food Science, Chongju National College of Science and Technology,
Chongju 367-701, Korea
3Department of Social Physical Education, Soonchunhyang University, Chungnam 337-880, Korea
4Nel Biotech Co., LTD., Kyonggi456-880, Korea
5Graduate School of Biotechnology, Korea University, Seoul 136-701, Korea
6Department of Food and Nutrition, College of Health Sciences, Korea University, 1 Jeongneung-dong,
Sungbuk-ku, Seoul 136-703, Korea
Received March 12, 2001; Accepted June 1, 2001
The anti-stress and anti-fatigue effects on rats and mice of a hot water extract of rice bran fermented with Saccharomyces cerevisae IFO 2346 were investigated. Oral administration (1 g/kg/day) of the hot water extract of fermented rice bran (FRB) inhibited major changes in the weight of the adrenal, thymus, spleen and thyroid, showing an anti-stress effect. The hot water extract of FRB also inhibited increases in the GPT and LDH activity, cholesterol and glucose in the serum. The administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase in the anti-fatigue effect. It is considered from these results that FRB had anti-stress and anti-fatigue effects.
Key words: rice bran; anti-stress; anti-fatigue; Saccharomyces cerevisae
-28-
Note
The Long Terminal Repeat (LTR) Sequence of marY1, a Retroelement
from the Ectomycorrhizal Homobasidiomycete Tricholoma matsutake,
is Highly Conserved in Various Higher Fungi
Hitoshi MURATA, Yasumasa MIYAZAKI, and Katsuhiko BABASAKI
Department of Applied Microbiology and Mushroom Sciences, Forestry ＆ Forest Products Research Institute,
P.O.Box 16, Tsukuba-Norin 305-8687, Japan
Received March 21, 2001; Accepted June 20, 2001
marY1 is an LTR-retroelement from the homobasidiomycete Tricholoma matsutake. Nucleotide sequences that correspond to the putative U3-R region and the R-U5 region of marY1 are highly conserved in various higher fungi. Data suggest that the LTR sequence of marY1 originated early in the evolution of higher fungi and has become widely distributed. Therefore, it may be useful for the construction of an LTR-mediated transformation system in basidiomycetes.
Key words: basidiomycetes; LTR-retroelement; recombinant systems; Saccharomyces cerevisiae; Schizosaccharomyces pombe
-29-
Note
marY2N, a LINE-Like Non-Long Terminal Repeat (Non-LTR) Retroelement
from the Ectomycorrhizal Homobasidiomycete Tricholoma matsutake
Hitoshi MURATA,1 Yasumasa MIYAZAKI,1 and Akiyoshi YAMADA2
1Department of Applied Microbiology and Mushroom Sciences, Forestry ＆ Forest Products Research Institute,
P.O.Box 16, Tsukuba-Norin 305-8687 Japan
2School of Agricultural Sciences, Shinshu University, Minami Minowa 8304, Nagano 399-4598 Japan
Received March 21, 2001; Accepted June 20, 2001
A LINE-like non-LTR retroelement designated marY2N was cloned from the ectomycorrhizal homobasidiomycete Tricholoma matsutake. marY2N has open reading frames that correspond to gag and pol, and a putative promoter and consensus sequences common to those of the mutators from fruit flies. While it is common to T. matsutake and Tricholoma magnivelare, marY2N does not reside in any other species of Tricholoma tested.
Key words: ectomycorrhizal fungi; homobasidiomycetes; LINE-like non-LTR retroelement; Tricholoma matsutake
-30-
Note
Antibacterial Agents that Inhibit Histidine Protein Kinase YycG
of Bacillus subtilis
Kaneyoshi YAMAMOTO,1 Takashi KITAYAMA,1 Shu MINAGAWA,1 Takafumi WATANABE,1
Seiji SAWADA,2 Tadashi OKAMOTO,1 and Ryutaro UTSUMI1†
1Department of Agricultural Chemistry, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
2Kyoto University of Education, Kyoto612-0863, Japan
Received March 30, 2001; Accepted June 6, 2001
We demonstrated in vitro that YycG-YycF of Bacillus subtilis constitutes a two-component system and shows a specificity of the sensor protein for the cognate phosphorylation partner. Based on inhibition of such an autophosphorylation of YycG, we searched imidazole and zerumbone derivatives to identify the antibacterial agents such as NH125, NH126, NH127, and NH0891.
Key words: two-component system; signal transduction; histidine kinase inhibitors; antimicrobial agents
-31-
Note
Isolation and Identification of Antheridiogens in the Ferns, Lygodium microphyllum
and Lygodium reticulatum
Masami KURUMATANI,1,2 Ken YAGI,1 Takashi MURATA,3,† Meguru TEZUKA,2
Lewis N. MANDER,4 Makoto NISHIYAMA,1 and Hisakazu YAMANE1,††
1Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2Saitama Institute of Technology, 1690 Fusaiji, Okabe Town, Ohsato District, Saitama 369-0293, Japan
3Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba,
Meguro-ku, Tokyo 153-8902, Japan
4Reseach School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
Received March 30, 2001; Accepted June 1, 2001
Antheridiogens in culture media of 6-week-old prothallia of two species of Schizaeaceous ferns, Lygodium microphyllum and Lygodium reticulatum, were analyzed by gas chromatography-mass spectrometry. In both species, the gibberellin A73 methyl ester (GA73-Me) was identified as the most abundant antheridiogen, and the methyl esters of GA9 and of several monohydroxyGA73 derivatives were also detected. Since both species produced antheridiogens at a high level, they were classified into high-antheridiogen-producing ferns. The response to GA73-Me of gametophytes of both species is also discussed.
Key words: fern; Lygodium microphyllum; Lygodium reticulatum; antheridiogen; gibberellin A73 methyl ester
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Structural Elucidation and Synthesis of 3-Hydroxybenzene-1,2-dicarbaldehyde
from Astigmatid Mites†
Tomoyo SAKATA and Yasumasa KUWAHARA††
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku,
Kyoto 606-8502, Japan
Received April 2, 2001; Accepted May 8, 2001
The structure of a novel aromatic compound contained in the unidentified Rhizoglyhus mite (Acaridae: Astigmata) was elucidated, without its isolation, to be 3-hydroxybenzene-1,2-dicarbaldehyde (tentatively named γ-acaridial) by a combination of GC/MS and GC/FT-IR together with knowledge of related mite compounds. The structure was confirmed by a 5-step synthesis, starting from methyl 3-hydroxybenzoate, in a 15％ overall yield. The compound is widely distributed not only among Astigmata but also among Oribatida, although its biological function is obscure at present.
Key words: aromatic dialdehyde; Astigmata; astigmatic mite; 3-hydroxybenzene-1,2-dicarbaldehyde
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Hypoglycemic Effect of a Hot-water Extract from Defatted Sesame
(Sesamum indicum L.) Seed on the Blood Glucose Level
in Genetically Diabetic KK-Ay Mice
Hisanao TAKEUCHI,† Lau Yan MOOI, Yoko INAGAKI, and Puming HE
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya,
Shizuoka 422-8529, Japan
Received April 2, 2001; Accepted June 8, 2001
Genetically diabetic (type II) KK-Ay mice, male and 5 weeks of age, were divided into one group of 12 mice that were fed on a basal (BAS) diet and three groups of 6 mice each that were fed on the test diets for 4 weeks. Each test diet contained 4.0％ of the hot-water extract (HES) from defatted sesame (Sesamum indicum L.) seed, 1.4％ of the water eluent fraction (WFH) of HES or 0.7％ of the methanol eluent fraction (MFH) of HES from a glass column packed with HP-20 resin. At the end of the feeding period, the BAS group was divided into the MAL and MALH groups which were respectively force-fed with 1 ml per mouse of a 20％ maltose solution in water with or without 4.0％ HES. The plasma glucose concentration and amount of urinary excreted glucose were lower from the HES and MFH diets than from the BAS and WFH diets. The levels of plasma glucose and serum insulin were lower in the MALH group than in the MAL group. These results indicate that HES and MFH had a reductive effect on the plasma glucose concentration of KK-Ay mice, and this effect is suggested to have been caused by the delayed glucose absorption.
Key words: sesame (Sesamum indicum L.) seed; hot-water extract from defatted sesame; hypoglycemic effect; genetically diabetic KK-Ay mice
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Chemical Synthesis and Biological Activity of The Gelatinase Biosynthesis-
Activating Pheromone of Enterococcus faecalis and Its Analogs
Jiro NAKAYAMA,†,†† Yong CAO, Takaaki HORII, Shohei SAKUDA, and Hiromichi NAGASAWA
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences,
The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Received April 2, 2001; Accepted May 24, 2001
An 11-residue peptide lactone, termed the gelatinase biosynthesis-activating pheromone (GBAP), triggers the production of the pathogenicity-related extracellular proteases, gelatinase and serine protease, in Enterococcus faecalis. In this study, we synthesized GBAP and its analogs and examined their gelatinase biosynthesis-inducing activity. This study on the structure-activity relationship shows that a lactone ring was indispensable for the activity.
Key words: gelatinase biosynthesis-activating pheromone; Enterococcus faecalis; peptide lactone; peptide pheromone; quorum sensing
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Lactobacillus casei NY1301 Increases the Adhesion of Lactobacillus gasseri
NY0509 to Human Intestinal Caco-2 Cells
Yukimasa AZUMA and Manabu SATO
Central Research Institute, Nissin Food Products Co., Ltd., 2247, Noji, Kusatsu, Shiga 525-0055, Japan
Received Aplil 3, 2001; Accepted June 8, 2001
In the presence of Lactobacillus casei NY1301, the adhesion of Lactobacillus gasseri NY0509 to cultured human intestinal Caco-2 cells was significantly increased (P＜0.01). In contrast, L. gasseri NY0509 did not affect the adhesion of L. casei NY1301. A heat-stable cell component of L. casei NY1301 was involved in this increase of adhesion. These results suggest that a combination of these strains may have synergistic effects of adhesion to human intestinal mucosa.
Key words: Lactobacillus gasseri; Lactobacillus casei; Caco-2 cells; adhesion
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Isolation and Some Characterization of an Acidic Polysaccharide
with Anti-calcification Activity from Coccoliths of a Marine Alga,
Pleurochrysis carterae
Noriaki OZAKI, Shohei SAKUDA, and Hiromichi NAGASAWA†
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences,
The University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan
Received April 4, 2001; Accepted June 4, 2001
Coccolith is a calcified scale with species-specific fine structure produced by marine unicellular coccolithophorid algae, and consists of calcium carbonate crystals and organic matrices. EDTA-soluble organic materials extracted from coccoliths of Pleurochrysis carterae showed anti-calcification activity. They were separated by anion-exchange HPLC, and two fractions, fractions A and B, were obtained. Fraction B, which was more active than fraction A, was further separated into six consecutive fractions, B1--B6, by second anion-exchange HPLC. 1H NMR spectral analyses of these fractions suggested that a novel acidic polysaccharide, designated CMAP, existed throughout B1--B6 and that the latter four fractions mainly contained another acidic polysaccharide, PS-2, characterized previously. Since PS-2 did not show anti-calcification activity, CMAP was found to be the active principle.
Key words: acidic polysaccharide; biomineralization; calcification; coccolith; Pleurochrysis carterae
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Screening for Phenoloxidases from Edible Mushrooms
Kohei MORISAKI,1 Tsutomu FUSHIMI,2 Satoshi KANEKO,2 Isao KUSAKABE,1
and Hideyuki KOBAYASHI2†
1Institute of Applied Biochemistry, University of Tsukuba, Ibaraki 305-0061, Japan
2National Food Research Institute, Ibaraki 305-8642, Japan
Received April 10, 2001; Accepted May 25, 2001
A screening test for phenoloxidases from edible mushrooms was done on potato dextrose agar plates that contained phenolic chemicals. Many edible mushrooms showed positive reactions on the agar plates. Among them, Auricularia auricula-judae, Clitocybe nebularis, Lentinus edodes, Pholiota aurivella, and Pseudohiatula oshimae produced a considerable amount of phenoloxidases, and these enzymes showed maximum activities in the acidic pH region.
Key words: phenoloxidase; edible mushroom; laccase; manganese peroxidase; lignin peroxidase
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Apoptosis induced by Picolinic Acid-related Compounds in HL-60 Cells
Shin OGATA, Kazuko INOUE, Keiko IWATA, Katsuzumi OKUMURA, and Hiroshi TAGUCHI†
Laboratory of Molecular and Cellular Biology, Department of Life Science, Faculty of Bioresources,
Mie University, Tsu, Mie 514-8507, Japan
Received April 16, 2001; Accepted June 4, 2001
We have found that niacin-related compounds, particularly picolinic acid, induced apoptosis in human leukemia cells. In this paper, we investigated whether various picolinic acid-related compounds had apoptosis-inducing activities or not. Particularly, fusaric acid, picolinaldehyde, nicotinaldehyde, 2-aminopyridine, and 3-aminopyridine also induced apoptosis in HL-60 cells. These results suggest that pyridine substituted with various groups and the consequent change of resonance structure may have an important role in the induction of apoptosis.
Key words: niacin; picolinic acid; NAD; apoptosis; HL-60
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No Factors Except for the Hap Complex increase the Taka-amylase A Gene
Expression by Binding to the CCAAT Sequence in the Promoter Region
Masashi KATO,† Fumiko NARUSE, Tetsuo KOBAYASHI, and Norihiro TSUKAGOSHI
Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences,
Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
Received April 17, 2001; Accepted May 31, 2001
To examine the possibility that factors different from the Hap complex are involved in increasing Taka-amylase A gene (taa) expression in Aspergillus nidulans, either the authentic taa gene or the mutant taa gene with a replacement of the CCAAT box was expressed in either a wild type strain or a mutant strain lacking the functional Hap complex (hapCΔ). When the mutant taa was expressed in the hapCΔ strain, enzyme activity was as low as that of the hapCΔ strain transformed with the authentic taa gene, indicating that no factors except for the Hap complex increase transcription of the taa gene by binding to the CCAAT sequence.
Key words: Hap complex; Aspergillus ssp; amylase; CCAAT
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Note
Characterization of Nucleoside Diphosphate Kinase
from Moderately Halophilic Eubacteria
Yasushi YONEZAWA, Hiroko TOKUNAGA, Matsujiro ISHIBASHI, and Masao TOKUNAGA†
Laboratory of Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University,
1-21-24 Korimoto, Kagoshima 890-0065, Japan
Received April 23, 2001; Accepted May 24, 2001
Nucleoside diphosphate kinase was purified to apparent homogeneity from naturally isolated moderately halophilic eubacteria by ATP-agarose and phenyl-5PW column chromatographies. The molecular mass of this enzyme was 15 kDa by time-of-flight mass-spectrometry. This protein showed anomalous mobility on SDS-PAGE which is typical of a halophilic protein. It was stable and active over a wide range of salt concentrations, from 0 to 4.0 M NaCl.
Key words: nucleoside diphosphate kinase; halophilic enzyme; eubacterial halophile
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Genetic Analysis of the His-to-Asp Phosphorelay Implicated
in Mitotic Cell Cycle Control: Involvement of Histidine-Kinase Genes
of Schizosaccharomyces pombe
Keisuke AOYAMA, Hirofumi AIBA,† and Takeshi MIZUNO
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku,
Nagoya 464-8601, Japan
Received April 24, 2001; Accepted May 28, 2001
Common histidine-to-aspartate (His-to-Asp) phosphorelay signaling systems involve three types of signaling components: a sensor His-kinase, a response regulator, and a histidine-containing phosphotransfer (HPt) protein. In the fission yeast Schizosaccharomyces pombe, two response regulators, Mcs4 and Prr1, have been identified, and it was shown that they are involved in signal transduction in stress responses. Furthermore, Mcs4 and Prr1 appear to be involved in mitotic cell-
cycle control and meiosis, respectively. Recently we have identified Spy1 (also known as Mpr1), which encodes an HPt phosphotransmitter, and reported that Spy1, together with Mcs4, plays a role in cell cycle regulation. In this study, we identified and characterized three genes encoding histidine kinase, named Phk1, Phk2, and Phk3 (S. pombe histidine kinase) (also referred as Mak2, Mak3, and Mak1, respectively). Deletion of individual kinase genes has no apparent phenotypes but multiple deletion of these kinases showed the same phenotype of Spy1 (Mpr1)-deficient cells, indicating precocious entry into M phase. These results indicated that three histidine kinases that work upstream of the HPt-transmitter, Spy1 (Mpr1), have a redundant function in cell cycle control.
Key words: Schizosaccharomyces pombe; His-to-Asp phosphorelay; His-kinases; HPt signal transducers; response regulators
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Purification and Some Properties of an Inhibitor for a Yeast Pleiotropic
Drug Resistant Pump from Kitasatospora sp. E-420
Anoja WANIGASEKERA, Kazumi HIRAGA,† Nobuyuki HAMANAKA,＊ and Kohei ODA
Department of Applied Biology, Faculty of Textile Science, Kyoto Institute of Technology, Matsugasaki,
Sakyo-ku, Kyoto 606-8585, Japan
＊Minase Research Institute, Ono Pharmaceutical Ltd., Shimamoto, Mishima, Osaka 618-8585, Japan
Received May 7, 2001; Accepted May 25, 2001
A strain producing an inhibitor for pleiotropic drug resistant 5 (Pdr5) was isolated using our original screening system in yeast. The strain was classified and named as Kitasatospora sp. E-420. The purified inhibitor (molecular weight＝1,193 by FAB-MS) inhibited a Pdr5-mediated efflux of cycloheximide and cerulenin. The intracellular accumulation of a fluorescent dye, rhodamine 123, by the inhibitor was also confirmed. Some physicochemical data suggested that the Pdr5-specific inhibitor was different from an immunosuppressant, FK506, reported as the only inhibitor of Pdr5 in vivo.
Key words: pleiotropic drug resistance; Pdr5; Saccharomyces cerevisiae; inhibitor; drug susceptibility
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Note
Antimutagenic Activity against Trp-P-1 of the Edible Thai Plant,
Oroxylum indicum Vent.
Kazuhiko NAKAHARA,† Mayumi ONISHI-KAMEYAMA,1 Hiroshi ONO,1
Mitsuru YOSHIDA,1 and Gassinee TRAKOONTIVAKORN2
Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba,
Ibaraki 305-8686, Japan
1National Food Research Institute, 2-1-12 Kan-non dai, Tsukuba, Ibaraki 305-8642, Japan
2Institute of Food Research and Product Development, Kasetsart University, Bangkok 10903, Thailand
Received May 14, 2001; Accepted June 18, 2001
A methanolic extract of Oroxylum indicum strongly inhibited the mutagenicity of Trp-P-1 in an Ames test. The major antimutagenic constituent was identified as baicalein with an IC50 value of 2.78±0.15 μM. The potent antimutagenicity of the extract was correlated with the high content (3.95±0.43％, dry weight) of baicalein. Baicalein acted as a desmutagen since it inhibited the N-hydroxylation of Trp-P-2.
Key words: antimutagenicity; Oroxylum indicum Vent.; flavonoid; baicalein; Trp-P-1
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Appearance of Poor-fermenting Variants in Brewing Yeast Culture
Hiromi YAMAGISHI,1 Toshifumi YUUKI,1 Noboru KAGAMI,1 Yukitomo YOKOGAWA,1
Kazunori SHIBATA,1 Masayo MINEMURA,2 and Yoshikazu OHYA2
1Brewing Research and Development Laboratory, Asahi Breweries, LTD. 1-21, Midori 1-chome,
Moriya-machi, Kitasoma-gun, Ibaraki 302-0106, Japan
2Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo,
Bldg. FSB-101, 5-1-5 Kashiwanoha, Kashiwa, Chiba Prefecture 277-8562, Japan
Received June 5, 2001; Accepted June 25, 2001
A class of yeast variants appears after cultivation of a bottom-fermenting brewing yeast strain, IFO2003. Although IFO2003 fails to grow well above 33°C, the variants can grow up to 34°C. Temperature-resistance and an acquired phenotype of maltose poor-fermentation ability are strictly correlated in the bottom-fermenting brewing yeast, enabling us to develop easy estimation of the fermentation ability of the variants.
Key words: fermentation; genetic instability; bottom-fermenting brewing yeast; temperature-sensitivity
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Characterization of the RcsC→YojN→RcsB Phosphorelay Signaling
Pathway Involved in Capsular Synthesis in Escherichia coli
Mian Hua CHEN, Shin-ichiro TAKEDA, Hisami YAMADA, Yuko ISHII,
Takafumi YAMASHINO, and Takeshi MIZUNO†
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku,
Nagoya 464-8601, Japan
Received June 15, 2001; Accepted July 11, 2001
Escherichia coli and other enteric microorganisms produce an extracellular polysaccharide capsule, called colanic acid, under certain environmental conditions. This capsular synthesis is regulated by the RcsC (sensor kinase)→YojN (phosphotransfer intermediate)→RcsB (response regulator) phosphorelay signal transduction under certain growth conditions. Nonetheless, little is known about signals that exaggerate the Rcs-system. To gain insight into signals that activate the Rcs-system, here we searched for genes that activate the Rcs-system, provided that those on a multicopy plasmid were introduced into E. coli. We identified several such genes, namely, rcsB, rcsA, djlA, lolA, and ompG. The DjlA, LolA, and OmpG proteins are particularly interesting in that they are all located on the cell surface, where the primary sensor RcsC histidine-kinase is localized. Implications of these findings are discussed with special reference to the mechanism by which RcsC perceives external signals.
Key words: Escherichia coli; His-to-Asp phosphorelay; capsular synthesis; signal transduction<QL>