(Vol.65 No.6 2001)
Conjugation of Arg-Gly-Asp (RGD) Sequence in Copolymer Bearing
Sugar
Moiety for Insulinoma Cell Line (MIN6) Culture
Kun NA,1 Hoo-Kyun CHOI,1 Toshihiro AKAIKE,2 and Keun-Hong PARK1 p.1284
Purification and Characterization of an Oligo-isomaltosaccharide
Synthase
from a Streptococcus sobrinus Glucosyltransferase-I Deficient Mutant.
Noriko SHINOZAKI-KUWAHARA,1,・ Mitsuo HAYAKAWA,2 Teruaki SHIROZA,2
Yoshimitsu ABIKO,2 and Kazuo FUKUSHIMA1 p.1290
Growth Promotion of Rice Seedlings by Allelopathic Polysaccharide
from Welsh Onion
Gyo-Cheol GOO, Sang-Tai CHOI,＊ Hyung-Geun AHN,＊ and Kyung-Sik SONG・ p.1296
Isolation and Antioxidant Activity of Galloyl Flavonol Glycosides
from the Seashore Plant, Pemphis acidula
Toshiya MASUDA,1,・ Kumiko IRITANI,1 Shigetomo YONEMORI,2 Yasuo OYAMA,1
and Yoshio TAKEDA1 p.1302
Characterization of Recombinant Yeast Exo-β-1,3-Glucanase (Exg
1p)
Expressed in Escherichia coli Cells
Kanako SUZUKI, Tomio YABE, Yutaka MARUYAMA, Keietsu ABE and Tasuku NAKAJIMA・
p.1310
Copper Staining Method for Extracting Biologically Active Proteins
from Native Gels
Jie WEN, Mei ZHANG, Thomas P. HORAN, John S. PHILO,＃ Tiansheng LI, Jette WYPYCH,
Elizabeth A. MENDIAZ, Keith E. LANGLEY, Kenneth H. AOKI, Moeka KUWAMOTO,
Yoshiko KITA,＃ and Tsutomu ARAKAWA＃ p.1315
Kinetic and Thermodynamic Analysis of Thermal Unfolding
of Recombinant Erythropoietin
Tsutomu ARAKAWA, John S. PHILO, and Yoshiko KITA p.1321
A Novel Rhamnose-binding Lectin Family from Eggs of Steelhead
Trout
(Oncorhynchus mykiss) with Different Structures and Tissue Distribution
Hiroaki TATENO,＊ Tomohisa OGAWA,＊ Koji MURAMOTO,＊,・ Hisao KAMIYA,＊＊
Toshiaki HIRAI,＊＊＊ and Mineo SANEYOSHI＊＊＊ p.1328
Effects of Dietary Pyrazinamide, an Antituberculosis Agent,
on the Metabolism
of Tryptophan to Niacin and of Tryptophan to Serotonin in Rats
Katsumi SHIBATA,＊ Tsutomu FUKUWATARI, and Etsuro SUGIMOTO p.1339
Calcium Ions Stabilize a Protein Structure of Hemolytic Lectin
CEL-III
from Marine Invertebrate Cucumaria echinata
Imre SALLAY, Sumiki TOJO, Koji NOMIYAMA, Yoshiaki KOUZUMA, Makoto KIMURA,
and Nobuyuki YAMASAKI p.1347
Milk Basic Protein Promotes Bone Formation and Suppresses Bone
Resorption
in Healthy Adult Men
Yasuhiro TOBA,1,・ Yukihiro TAKADA,1 Yasuhiro MATSUOKA,1 Yoshikazu MORITA,1
Mutsumi MOTOURI,1 Tomoko HIRAI,2 Toshiaki SUGURI,2 Seiichiro AOE,2
Hiroshi KAWAKAMI,1 Masayoshi KUMEGAWA,3 Akira TAKEUCHI,4 and Akira ITABASHI5
p.1353
New Allyl Ester Linker and Solid-phase Block Synthesis
of the Serglycin Core Region
Yuko NAKAHARA,1 Sumie ANDO,1 Yukishige ITO,1 Hironobu HOJO,2
and Yoshiaki NAKAHARA1,2・ p.1358
Glucosylceramide Synthesis Inhibitors Block Pharmacologically
Induced
Dispersal of the Golgi and Anterograde Membrane Flow from the Endoplasmic
Reticulum: Implication of Sphingolipid Metabolism in Maintenance
of the Golgi Architecture and Anterograde Membrane Flow
Machiko NAKAMURA,＊,・ Natsuko KUROIWA,＊,・ Yoshiki KONO,・ and Akira TAKATSUKI＊,・
p.1369
Molecular Cloning of groESL Locus, and Purification and Characterization
of Chaperonins, GroEL and GroES, from Bacillus brevis
Masao TOKUNAGA,＃,・ Yoichi SHIRAISHI＃ Masatake ODACHI,＃ Makoto MIZUKAMI,$
Hiroko TOKUNAGA,＃ John S. PHILO,+ Tsutomu ARAKAWA,+ Matsujiro ISHIBASHI,＃
Ryoichi TANAKA,＃ and Hiroaki TAKAGI$ p.1379
Note
Coupling of Fermentation and Esterification: Microbial Esterification
of Decanoic Acid with Ethanol Produced via Fermentation
Shinobu ODA1,・ and Hiromichi OHTA2 p.1388
Note
Characterization of Aspartate Kinase III of Bacillus subtilis
Nobuyuki KOBASHI, Makoto NISHIYAMA,・ and Hisakazu YAMANE p.1391
Note
Four Polyoxygenated Cyclohexenes from the Chinese Tree,
Uvaria Purpurea
Yoshifusa TAKEUCHI, Qian CHENG, Qing-Wen SHI, Takeyoshi SUGIYAMA,
and Takayuki ORITANI・ p.1395
Note
Properties of an Extracellular Polysaccharide Produced by a Strain
of Enterobacter Isolated from Pond Water
Yuka ISOBE,・ Yuki MATSUMOTO, Kumio YOKOIGAWA, and Hiroyasu KAWAI p.1399
Note
Mulberry Moracins: Scavengers of UV Stress-generated Free Radicals
Rashmi SHARMA,1,2 Arun SHARMA,1 Tetsuya SHONO,3 Mitsuo TAKASUGI,3 Akira SHIRATA,1
Tatsuhito FUJIMURA,2 and Hiroaki MACHII1＊ p.1402
Note
Molecular Cloning and Characterization of cel2
from the Fungus Cochlibolus carbonum
Joong-Hoon AHN,1・ Paola SPOSATO,2 Su-Il KIM,3 and Jonathan D. WALTON2 p.1406
Note
Stronger Suppression of Plasma Cholesterol and Enhancement
of the Fecal Excretion of Steroids by a Buckwheat Protein Product
than by a Soy Protein Isolate in Rats Fed on a Cholesterol-free Diet
Hiroyuki TOMOTAKE,・ Iwao SHIMAOKA, Jun KAYASHITA, Fumiyo YOKOYAMA,
Misao NAKAJOH, and Norihisa KATO＊ p.1412
Note
Effect of Dietary Histidine Content on the Change in Content of Skin Urocanic
Acid Isomers in Hairless Mice Irradiated with Ultraviolet B
Katsumi SHIBATA,・ Tsutomu FUKUWATARI, Satomi ZUSHI, and Etsuro SUGIMOTO p.1415
Note
Trehalose-producing Operon treYZ from Arthrobacter ramosus S34＊
Takuo YAMAMOTO,・ Kazuhiko MARUTA, Hikaru WATANABE, Hiroshi YAMASHITA,
Michio KUBOTA, Shigeharu FUKUDA, and Masashi KURIMOTO p.1419
Note
Cloning and Expression of CitPDS1, a Gene Encoding
Phytoene Desaturase in Citrus
Masayuki KITA, Akira KOMATSU, Mitsuo OMURA, Masamichi YANO,
Yoshinori IKOMA, and Takaya MORIGUCHI1,・ p.1424
Note
New Synthesis of Serricornin, the Female Sex Pheromone
of the Cigarette Beetle・
Ken FUJITA and Kenji MORI・・ p.1429
Note
Antifeedants against Acusta despesta from the Japanese Cedar,
Cryptomeria japonica II
Xiao Hui CHEN, Chul-Sa KIM,＊ Takehiro KASHIWAGI, Shin-ichi TEBAYASHI,
and Michio HORIIKE p.1434
Preliminary Communication
Occurrence of the Major Food Allergen, Ovomucoid, in Human Breast
Milk
as an Immune Complex
Junko HIROSE,1 Setsuko ITO,2 Noriko HIRATA,3 Shoko KIDO,3 Naofumi KITABATAKE,1
and Hiroshi NARITA3,・p.1438
Preliminary Communication
Inhibitory Effect of Monoacylglycerol on Fatty Acid Uptake
into Rat Intestinal Epithelial Cells
Kaeko MUROTA,・ Noriko MATSUI, Teruo KAWADA, Nobuyuki TAKAHASHI,
and Tohru FUSHUKI・・p.1441
Preliminary Communication
Oxidation of Bisphenol A and Related Compounds
Mitsuru YOSHIDA,・ Hiroshi ONO, Yoshiko MORI, Yoshihiro CHUDA,＊ and Koichi ONISHI＊ p.1444
-1-
Cytokinin-induced Gene Expression in Cultured Green Cells
of Nicotiana tabacum Identified by Fluorescent Differential Display
Takuma KIMURA, Takeshi NAKANO,・ Noriyuki TAKI, Mayuko ISHIKAWA,
Tadao ASAMI, and Shigeo YOSHIDA
Plant Functions Laboratory, RIKEN (The Institute of Physical and Chemical Research),
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Received September 20, 2000; Accepted February 5, 2001
The cell growth and plastid development of cultured green tobacco cells were maintained by the phytohormone cytokinin. After subculture into cytokinin-free medium, when cytokinin treatment was resumed, physiological changes induced by cytokinin were analyzed. Changes in chlorophyll biosynthesis and photosynthetic gene expression were observed 1 week after cytokinin induction, and changes in cell growth were observed 2 weeks after cytokinin induction. Two cytokinin-induced genes (cig) were isolated from these cells using the fluorescent differential display technique. Northern analysis confirmed that expression of these cig was induced by both natural and synthetic cytokinins. The expression of cig1 was also induced by abscisic acid, and its cDNA sequence was similar to the proline dehydrogenase gene. The expression of cig2 is specific to cytokinin and is not induced by other phytohormones. The amino acid sequence encoded by cig2 is similar to the GDP/GTP exchange factor eIF2B, which regulates translation initiation. The expression of these cig suggests a complex induction system involving cytokinin and other phytohormones.
Key words: cytokinin; tobacco; differential display; GDP/GTP exchange factor; proline dehydrogenase
-2-
Conjugation of Arg-Gly-Asp (RGD) Sequence in Copolymer Bearing Sugar
Moiety for Insulinoma Cell Line (MIN6) Culture
Kun NA,1 Hoo-Kyun CHOI,1 Toshihiro AKAIKE,2 and Keun-Hong PARK1
1College of Pharmacy, Chosun University, 375 Seoseok-dong Dong-ku, Kwangju 501-759, Korea
2Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226, Japan
Received October 16, 2000; Accepted January 25, 2001
Copolymers composed of an Arg-Gly-Asp (RGD) sequence for the adhesion molecule and sugar moieties were synthesized for an insulinoma cell (MIN6) culture. MIN6 cells attached on the poly(N-p-vinylbenzyl-D-maltonamide-co-6-(p-vinylbenzamido)-hexanoic acid-g-GRGDS) (p(VMA-co-VBGRGDS))-coated dishes were in a more aggregated form than other polymer-coated surfaces. P(VMA-co-VBGRGDS) also shows faster proliferation of MIN6 cells (about 18％ higher) than with p(VLA-co-VBGRGDS). By interaction between cell and matrix, about 80％ greater insulin secretion from MIN6 cells was produced with the p(VMA-co-VBGRGDS), and about 50％ greater insulin secretion was produced with the poly(N-p-vinylbenzyl-D-
lactonamide-co-6-(p-vinylbenzamido)-hexanoic acid-g-GRGDS) (p(VLA-co-VBGRGDS) as compared with unstimulated cells. Moreover, attachment of MIN6 cells treated with RGD monomer was suppressed approximately 50％ for the p(VMA-co-VBGRGDS) surface. This result supported the idea that conjugation of adhesion molecules of RGD peptide in p(VMA-co-VBGRGDS) copolymer specifically interact with integrin families on MIN6 cell membrane.
Key words: RGD; copolymer; MIN6 cells; p(VMA-co-VBRGDS); sugar
-3-
Purification and Characterization of an Oligo-isomaltosaccharide Synthase
from a Streptococcus sobrinus Glucosyltransferase-I Deficient Mutant.
Noriko SHINOZAKI-KUWAHARA,1,・ Mitsuo HAYAKAWA,2 Teruaki SHIROZA,2
Yoshimitsu ABIKO,2 and Kazuo FUKUSHIMA1
Departments of 1Microbiology and 2Biochemistry, Nihon University school of Dentistry at Matsudo,
Matsudo, Chiba 271-8587, Japan
Received October 23, 2000; Accepted January 29, 2001
One glucosyltransferase (GTF) -I deficient mutant of Streptococcus sobrinus strain B13N was isolated through chemical mutagenesis with ethyl methanesulfonate, and characterized. This mutant, designated as B13N-Id, readily allowed us to purify a homogeneous oligo-isomaltosaccharide synthase (GTF-S) from its culture fluid.
The purified GTF-S was only recognized with rabbit polyclonal antibody against recombinant GTF-S from an Ecsherichia coli MD124 clone expressing the B13N gtfS gene, and showed the almost same enzymatic properties as the recombinant enzyme. A double reciprocal plot of the B13N GTF-S for sucrose was biphasic, and the affinity for this substrate was high compared to that of GTF-S enzymes from other strains.
Key words: glucosyltransferase; oligo-isomaltosaccharide; Streptococcus sobrinus
-4-
Growth Promotion of Rice Seedlings by Allelopathic Polysaccharide
from Welsh Onion
Gyo-Cheol GOO, Sang-Tai CHOI,＊ Hyung-Geun AHN,＊ and Kyung-Sik SONG・
Department of Agricultural Chemistry, Kyungpook National University, 1370 Sankyuk-Dong,
Taegu 702-701, Korea
＊Department of Horticulture, Kyungpook National University, 1370 Sankyuk-Dong, Taegu 702-701, Korea
Received October 30, 2000; Accepted February 3, 2001
The underground portion of the Welsh onion (Allium fistulosum) was extracted and separated into seven fractions to purify allelopathic compounds that were found to promote the growth of rice seedlings (Oryza sativa). The 80％ (v/v) ethanol-insoluble fraction of the hot water extract showed the highest growth-promoting effect. Purification by DEAE-cellulose chromatography gave four fractions, AD-1, 2, 3 and 4. AD-3 at 1000 ppm stimulated root and shoot growth by about 2.4 and 1.5 times over the respective water and sucrose-treated controls. The molecular weight of AD-3 was roughly estimated as 630 kDa by gel permeation chromatography. Seventy two percent (by wt.) of AD-3 was a carbohydrate and no proteins were detected. A GC analysis of the neutral sugar composition revealed the presence of Gal (50.1％), Man (17.9％), Ara (10.4％), Rha (8.8％), Glc (7.2％) and Xyl (5.6％). About 3％ (by wt.) of the total carbohydrate was uronic acid, which was identified as GalU by a GC analysis. The remainder of AD-3 was extracted in ethyl acetate after its hydrolysis with 2 M HCl. The major component of the ethyl acetate-soluble fraction was identified as unsaturated linear primary alcohols, 1-tetradecanol and 1-octadecanol (16％ and 84％ by peak areas from GC, respectively) by means of NMR and GC-MS. Sole or combined treatment of these alcohols did not affect the growth of rice seedlings. After partial hydrolysis with 0.2 M trifluoroacetic acid or by a sodium periodate treatment, the activity of AD-3 had completely disappeared, suggesting that the sugar moiety and/or molecular size were important for the activity.
Key words: Allium fistulosum; rice seedlings; growth-promotion; allelopathy; polysaccharide-alcohol complex
-5-
Isolation and Antioxidant Activity of Galloyl Flavonol Glycosides
from the Seashore Plant, Pemphis acidula
Toshiya MASUDA,1,・ Kumiko IRITANI,1 Shigetomo YONEMORI,2 Yasuo OYAMA,1
and Yoshio TAKEDA1
1Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770-8502, Japan
2Tropical Biosphere Research Center, University of Ryukyus, Taketomi, Okinawa 907-1541, Japan
Received November 6, 2000; Accepted January 25, 2001
Four kinds of galloyl flavonol glycosides were found in the leaf extract of Pemphis acidula, a plant growing on the subtropical seashore. Their chemical structures were elucidated to be quercetin or kaempferol 6!--O--galloyl-β-D-glycosides by using spectroscopic and chemical analyses. One of the flavonols, kaempferol-3--O--(6--O--galloyl-β-D-galactopyranoside), was newly isolated from natural sources and its structure was completely determined in this investigation. The antioxidant-related activities of the galloyl flavonoids were examined by the DPPH antiradical activity, inhibition of methyl linoleate oxidation, and inhibition of oxidative cell death. These results were compared with those of the corresponding non-galloylated flavonol glycosides and their aglycones. The galloyl flavonoids showed more efficient activity than that of the corresponding flavonol glycosides, but not more than that of the corresponding aglycones in the three assays applied.
Key words: galloyl flavonol glycoside; Pemphis acidula; seashore plant; antioxidant activity; oxidative cell death
-6-
Characterization of Recombinant Yeast Exo-β-1,3-Glucanase (Exg 1p)
Expressed in Escherichia coli Cells
Kanako SUZUKI, Tomio YABE, Yutaka MARUYAMA, Keietsu ABE and Tasuku NAKAJIMA・
Divison of Applied Life Science, Graduate School of Agricultural Science, Tohoku University, Sendai,
981-8555, Japan
Received November 22, 2000; Accepted January 30, 2001
Yeast exo-β-1,3-glucanase gene (EXG1) was expressed in Escherichia coli and the recombinant enzyme (Exg1p) was characterized. The recombinant Exg1p had an apparent molecular mass of 45 kDa by SDS-PAGE and the enzyme has a broad specificity for β-1,3-linkages as well as β-1,6-linkages, and also for other β-glucosidic linked substrates, such as cellobiose and pNPG. Kinetic analyses indicate that the enzyme prefers small substrates such as laminaribiose, gentiobiose, and pNPG rather than polysaccharide substrates, such as laminaran or pustulan. With a high concentration of laminaribiose, the enzyme catalyzed transglucosidation forming laminarioligosaccharides. The enzyme was strongly inhibited with high concentrations of laminaran.
Key words: exo-β-1,3-glucanase gene (EXG 1); Saccharomyces cerevisiae; recombinant exo-β-1,3-glucanase (Exg1p)
-7-
Copper Staining Method for Extracting Biologically Active Proteins
from Native Gels
Jie WEN, Mei ZHANG, Thomas P. HORAN, John S. PHILO,＃ Tiansheng LI, Jette WYPYCH,
Elizabeth A. MENDIAZ, Keith E. LANGLEY, Kenneth H. AOKI, Moeka KUWAMOTO,
Yoshiko KITA,＃ and Tsutomu ARAKAWA＃
Amgen, Inc., Amgen Center, Thousand Oaks, CA 91320, U.S.A.
＃Alliance Protein Laboratories, 3957 Corte Cancion, Thousand Oaks, CA 91360, U.S.A.
Received November 28, 2000; Accepted January 24, 2001
An attempt was made to make protein bands visible on native gel using copper staining, since such a mild staining procedure would make the entire native gel electrophoresis process non-denaturing. Copper staining not only was able to detect various proteins on native gel with reasonable sensitivity, but also made extraction and recovery of active proteins possible from the gel using a gentle procedure.
Key words: copper staining; native gel; non-denaturing; protein recovery; extraction of protein
-8-
Kinetic and Thermodynamic Analysis of Thermal Unfolding
of Recombinant Erythropoietin
Tsutomu ARAKAWA, John S. PHILO, and Yoshiko KITA
Alliance Protein Laboratories, 3957 Corte Cancion, Thousand Oaks, CA 91360, USA
Received December 1, 2000; Accepted February 12, 2001
Thermal stress was used to assess the stability of recombinant human erythropoietin (EPO) derived from Chinese hamster ovary cells. In 20 mM phosphate at pH 7.0, this protein had a highly reversible thermal unfolding as observed by far UV circular dichroism (CD) and native gel analysis, with no indication of protein aggregation. It had a relatively low melting temperature at 53°C. Assuming a two-state transition, the observed reversibility permits thermodynamic analysis of the unfolding of EPO, which shows that the free energy of unfolding at 25°C is only 6--7 kcal/mol. Upon heating to 79°C over 30 min, however, this protein does undergo aggregation as assessed by native gel. In 20 mM phosphate and citrate at pH 7.0, the results are similar, i.e., EPO suffered a substantial aggregation, while it showed little aggregation in 20 mM Tris or histidine at pH 7.0 and 20 mM glycine at pH 6.3 under identical heat treatment.
Key words: erythropoietin; thermal unfolding; aggregation; reversibility; native gel
-9-
A Novel Rhamnose-binding Lectin Family from Eggs of Steelhead Trout
(Oncorhynchus mykiss) with Different Structures and Tissue Distribution
Hiroaki TATENO,＊ Tomohisa OGAWA,＊ Koji MURAMOTO,＊,・ Hisao KAMIYA,＊＊
Toshiaki HIRAI,＊＊＊ and Mineo SANEYOSHI＊＊＊
＊Department of Biological Resource Sciences, Graduate School of Agricultural Science, Tohoku University,
Sendai 981-8555, Japan
＊＊School of Fisheries Sciences, Kitasato University, Sanriku, Iwate 022-0101, Japan
＊＊＊Department of Biological Sciences, Teikyo University of Science and Technology, Uenohara,
Yamanashi 409-0193, Japan
Received December 6, 2000; Accepted January 26, 2001
An L-rhamnose-binding isolectin named STL3 (subunit Mr, 21.5 k) was isolated from eggs of the steelhead trout (Oncorhynchus mykiss) in addition to STL1 (subunit Mr, 31.4 k) and STL2 (subunit Mr, 21.3 k) that had been already isolated. STLs were composed of noncovalently linked subunits. The primary structures of STL1 and STL3 were analyzed by the combined use of protein sequencing and cDNA sequencing. A cDNA encoding STL2, of which the protein sequence had been previously studied, was also analyzed. The STL1 subunit (289 amino acid residues) had different structural properties compared to those of the STL2 subunit (195 amino acid residues) and the STL3 subunit (195 amino acid residues); e.g., the number of repeated domain (three for STL1, and two for STL2 and STL3), although all of them were composed of tandemly repeated homologous domains (40 to 53％ identities).
The lectin levels in various tissues and during the embryonic development showed that STL1 had different distribution and expression profiles from those of STL2 and STL3. Although STL1 could be detected in several tissues and serum of both male and female steelhead trout, STL2 and STL3 were only abundant in the ovary. STL2 and STL3 levels dramatically decreased just after hatching, however, the STL1 level increased temporarily. These results indicate that the multiple lectins from eggs of the steelhead trout form a novel rhamnose-binding lectin family with different structures and tissue distribution to share distinct functions in eggs.
animal lectin; cDNA cloning; fish egg; rhamnose-binding lectin; steelhead trout
-10-
Effects of Dietary Pyrazinamide, an Antituberculosis Agent, on the Metabolism
of Tryptophan to Niacin and of Tryptophan to Serotonin in Rats
Katsumi SHIBATA,＊ Tsutomu FUKUWATARI, and Etsuro SUGIMOTO
Course of Food Science and Nutrition, Department of Life Style Studies, School of Human Cultures,
The University of Shiga Prefecture, 2500 Hassakacho, Hikone, Shiga 522-8533, Japan
Received December 8, 2000; Accepted January 23, 2001
The effects of pyrazinamide on the metabolism of tryptophan to niacin and of tryptophan to serotonin were investigated to elucidate the mechanism for pyrazinamide action against tuberculosis. Weanling rats were fed with a diet with or without 0.25％ pyrazinamide for 61 days. Urine samples were periodically collected for measuring the tryptophan metabolites. The administration of pyrazinamide significantly increased the metabolites, 3-hydroxyanthranilic acid and beyond, especially quinolinic acid, nicotinamide, N＾{1}-methylnicotinamide, and N＾{1}-methyl-4-pyridone-3-carboxamide, and therefore significantly increased the conversion ratio of tryptophan to niacin and the blood NAD level . However, no difference in the upper metabolites of the tryptophan to niacin pathway such as anthranilic acid, kynurenic acid and xanthurenic acid was apparent between the two groups. No difference in the concentrations of trytptophan and serotonin in the blood were apparent either. It is suggested from these results that the action of pyrazinamide against tuberculosis is linked to the increase in turnover of NAD and to the increased content of NAD in the host cells.
Key words: pyrazinamide; tryptophan; nicotinamide; quinolinic acid; tuberculosis
-11-
Calcium Ions Stabilize a Protein Structure of Hemolytic Lectin CEL-III
from Marine Invertebrate Cucumaria echinata
Imre SALLAY, Sumiki TOJO, Koji NOMIYAMA, Yoshiaki KOUZUMA, Makoto KIMURA,
and Nobuyuki YAMASAKI
Laboratory of Biochemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture,
Graduate School, Kyushu University, Fukuoka 812-8581, Japan
Received December 18, 2000; Accepted February 9, 2001
CEL-III, a galactose/N-acetylgalactosamine (Gal/GalNAc)-specific lectin purified from a marine invertebrate, Cucumaria echinata, has a strong hemolytic activity, especially toward human and rabbit erythrocytes in the presence of Ca＾{2+}. We evaluated the role of Ca＾{2+} in hemagglutinating and hemolytic activities of CEL-III. We found that Ca＾{2+} is closely associated with both activities of CEL-III. The fluorescence spectra of CEL-III upon binding to Ca＾{2+} were measured. The result showed a structural change of CEL-III in the presence of Ca＾{2+}. The structural change of CEL-III upon Ca＾{2+} binding was further demonstrated by stabilization against urea denaturation and by insusceptibility to protease digestions. CEL-III was completely unfolded at a low concentration of 2 M urea, while CEL-III complexed with Ca＾{2+} was stable in 6 M urea. As for protease digestions, CEL-III monomer and oligomer were readily digested by trypsin, chymotrypsin, and papain in the absence of Ca＾{2+}, while they were insusceptible to the three proteases in the presence of Ca＾{2+}. The papain digestion of the decalcified oligomer produced a large C-terminal peptide, suggestting that the C-terminal region of CEL-III may participate in oligomerization of CEL-III as a core domain.
Key words: calcium ion; Cucumaria echinata; hemagglutination; hemolytic lectin; stability
-12-
Milk Basic Protein Promotes Bone Formation and Suppresses Bone Resorption
in Healthy Adult Men
Yasuhiro TOBA,1,・ Yukihiro TAKADA,1 Yasuhiro MATSUOKA,1 Yoshikazu MORITA,1
Mutsumi MOTOURI,1 Tomoko HIRAI,2 Toshiaki SUGURI,2 Seiichiro AOE,2
Hiroshi KAWAKAMI,1 Masayoshi KUMEGAWA,3 Akira TAKEUCHI,4 and Akira ITABASHI5
1Technology and Research Institute, Snow Brand Milk Products Co. Ltd., 1-1-2 Minamidai, Kawagoe,
Saitama 350-1165, Japan
2Product Planning Department, Snow Brand Milk Products Co. Ltd., 1-1-2 Minamidai, Kawagoe,
Saitama 350-1165, Japan
3Department of Oral Anatomy, Meikai University of Dentistry, 1-1 Keyakidai, Kakado,
Saitama 350-0248, Japan
4Luke Hospital, 3-6-1 Nogata, Nakano, Tokyo 165-0027, Japan
5Central Clinical Laboratory, Saitama Medical School, 38 Morohongo, Moroyama, Saitama 350-0495, Japan
Received December 20, 2000; Accepted January 19, 2001
Milk contains several components effective for bone health. In the previous in vitro and in vivo studies, we have shown that milk whey protein, especially its basic protein fraction (milk basic protein [MBP]), promoted bone formation and suppressed bone resorption. This present study examines the effect of MBP on the biochemical markers of bone metabolism in healthy adult men. Experimental beverages containing MBP (300 mg of MBP a day) were given to 30 normal healthy adult men for 16 days. The serum osteocalcin concentration had increased significantly after 16 days of ingesting the experimental beverage containing MBP. Urinary cross-linked N-teleopeptides of type-I collagen (NTx) excretion had decreased significantly after 16 days of ingesting MBP. The urinary NTx excretion was related to the serum osteocalcin concentration after 16 days of ingestion. These results suggest that MBP promoted bone formation and suppressed bone resorption, while maintaining the balance of bone remodeling.
Key words: milk basic protein; bone formation; bone resorption; remodeling; healthy adult men
-13-
New Allyl Ester Linker and Solid-phase Block Synthesis
of the Serglycin Core Region
Yuko NAKAHARA,1 Sumie ANDO,1 Yukishige ITO,1 Hironobu HOJO,2
and Yoshiaki NAKAHARA1,2・
1The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
2Department of Industrial Chemistry, Tokai University, Kitakaname 1117, Hiratsuka-shi,
Kanagawa 259-1292, Japan
CREST, Japan Science and Technology Corporation (JST)
Received December 20, 2000; Accepted January 17, 2001
The prototype glycopeptidyl fragments of serglycin, a proteoglycan with the characteristic peptide sequence of repeating L-seryl-L-glycine, were synthesized by a convergent method involving block condensation on a solid support. In order to facilitate detachment of the protected glycopeptides from the resin, a new allyl ester type of linker, which is cleavable by Pd(0)-catalysis, was designed and used in combination with the commercial acid-labile Sieber amide resin for the solid-phase synthesis. Glycopeptide blocks consisting of [O-(2,3,4-tri-O-acetyl-D-xylosyl)-L-seryl-L-glycine]n (n=1--8) were produced in good yields. Block condensation in a solution was also successful to synthesize up to the hexadecapeptide (n=8).
Key words: solid-phase synthesis; allyl linker; block condensation; serglycin; glycopeptide
-14-
Glucosylceramide Synthesis Inhibitors Block Pharmacologically Induced
Dispersal of the Golgi and Anterograde Membrane Flow from the Endoplasmic
Reticulum: Implication of Sphingolipid Metabolism in Maintenance
of the Golgi Architecture and Anterograde Membrane Flow
Machiko NAKAMURA,＊,・ Natsuko KUROIWA,＊,・ Yoshiki KONO,・ and Akira TAKATSUKI＊,・
＊Animal and Cellular Systems Laboratory, RIKEN (The Institute of Physical and Chemical Research),
Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
・School of Agriculture, Ibaraki University, Ami, Ibaraki 300-0332, Japan
・School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji,
Tokyo 192-0392, Japan
Received January 9, 2001; Accepted February 13, 2001
PDMP (D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol) and PPMP (D,L-threo-1-phenyl-2-hexadecanoylamino-3-morpholino-1-propanol), inhibitors of glucosylceramide synthesis, blocked brefeldin A (BFA)- and nordihydroguaiaretic acid-induced dispersal of the Golgi and trans Golgi network, and Golgi-derived vesicles were retained in the juxtanuclear region. PDMP and PPMP did not stabilize microtubules but blocked nocodazole-induced extensive fragmentation and dispersal of the Golgi, and large Golgi vesicles were retained in the juxtanuclear region. PPMP is a stronger inhibitor of glucosylceramide synthesis than PDMP, but PDMP showed a stronger activity against BFA-induced retrograde membrane flow. However, PPMP showed a stronger activity for Golgi disruption and inhibition of anterograde trafficking from the endoplasmic reticulum, and rebuilding of the Golgi architecture. Cumulatively, these results suggest that sphingolipid metabolism is implicated in maintenance of the Golgi architecture and anterograde membrane flow from the endoplasmic reticulum but not in Golgi dispersal induced by BFA.
Key words: retrograde membrane flow; anterograde membrane flow; sphingolipid metabolism; PDMP; brefeldin A
-15-
Molecular Cloning of groESL Locus, and Purification and Characterization
of Chaperonins, GroEL and GroES, from Bacillus brevis
Masao TOKUNAGA,＃,・ Yoichi SHIRAISHI＃ Masatake ODACHI,＃ Makoto MIZUKAMI,$
Hiroko TOKUNAGA,＃ John S. PHILO,+ Tsutomu ARAKAWA,+ Matsujiro ISHIBASHI,＃
Ryoichi TANAKA,＃ and Hiroaki TAKAGI$
＃Laboratory of Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University,
1-21-24 Korimoto, Kagoshima 890-0065, Japan
$Department of Research ＆ Development, Higeta Shoyu Co., Choshi, Chiba 288-0041, Japan
+Alliance Protein Laboratories, 3957 Corte Cancion, Thousand Oaks, California 91360 USA
Received January 9, 2001; Accepted February 9, 2001
The groESL locus of a protein-hypersecreting bacterium, Bacillus brevis, was cloned by PCR using primers designed based on the DNA sequence of a B. subtilis homolog. GroEL protein was purified to apparent homogeneity and its ATPase activity was characterized: it hydrolyzed ATP, CTP, and TTP in this order of reaction rate, and its specific activity for ATP was 0.1 μmole/min/mg protein. Purified GroEL forms a tetradecamer. GroEL was estimated to contain 22％ α-helix, 24％ β-sheet, and 19％ turn structures, by CD measurement. GroES protein was also highly purified to examine its chaperonin activity. GroEL protected from thermal inactivation of and showed refolding-
promoting activity for malate dehydrogenase, strictly depending on the presence of ATP and GroES.
Key words: groESL; GroEL; GroES; hrcA; Bacillus brevis
-16-
Note
Coupling of Fermentation and Esterification: Microbial Esterification
of Decanoic Acid with Ethanol Produced via Fermentation
Shinobu ODA1,・ and Hiromichi OHTA2
1Technical Research Laboratory, Kansai Paint Co. Ltd., 4-17-1 Higashi-Yawata, Hiratsuka,
Kanagawa 254-8562, Japan
2Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi,
Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
Received September 26, 2000; Accepted February 5, 2001
Two different kinds of bioprocess, ethanol fermentation and subsequent microbial esterification, were coupled using Issatchenkia terricola IFO 0933 in an interface bioreactor. The strain produced ethyl decanoate (Et-DA) by esterification of exogenous decanoic acid (DA) with ethanol produced via fermentation. The efficiency of the new coupling system depended on the concentration of glucose in a carrier and DA in an organic phase (decane) in an agar plate interface bioreactor. Optimum glucose content and DA concentration were 4％ and 29 mM, respectively.
Key words: ethanol fermentation; microbial esterification; coupling system; interface bioreactor
-17-
Note
Characterization of Aspartate Kinase III of Bacillus subtilis
Nobuyuki KOBASHI, Makoto NISHIYAMA,・ and Hisakazu YAMANE
Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Received October 20, 2000; Accepted January 29, 2001
A search in the Bacillus subtilis genome sequence found that the gene designated yclM encode(s) a protein showing significant identity in amino acid sequence to aspartate kinases. When yclM was introduced into Escherichia coli cells deficient in all three aspartate kinase genes, production of a protein with molecular size 50 kDa, which was similar to the value deduced from the nucleotide sequence of the gene, was observed. Expectedly, the protein purified to homogeneity had aspartate kinase activity. The enzyme was significantly inhibited by simultaneous addition of both threonine and lysine, which is a typical feature of aspartate kinase III of B. subtilis. The enzyme was very unstable in 10 mM tris-HCl (pH 7.5) buffer, but was stabilized by addition of 500 mM ammonium sulfate. Although all the aspartate kinases so far investigated are oligomeric enzymes, this aspartate kinase was suggested to be a monomer.
Key words: aspartate kinase; concerted inhibition; Bacillus subtilis
-18-
Note
Four Polyoxygenated Cyclohexenes from the Chinese Tree,
Uvaria Purpurea
Yoshifusa TAKEUCHI, Qian CHENG, Qing-Wen SHI, Takeyoshi SUGIYAMA,
and Takayuki ORITANI・
Laboratory of Applied Bioorganic Chemistry, Graduate School of Agricultural Science, Tohoku University,
1-1 Tsutsumidori-Amamiya, Aobaku, Sendai 981-8555, Japan
Received November 13, 2000; Accepted January 27, 2001
Two novel polyoxygenated cyclohexenes, 6-methoxyzeylenol (3) and 2-acetoxyzeylenone (4), together with two known compounds, zeylenol (1) and zeylenone (2), were isolated from the heartwood of the Chinese tree, Uvaria purpurea. Zeylenol (1) and zeylenone (2) both showed inhibitory activity toward the root growth of Lactuca sativa. Their structures were established by spectroscopic and chemical methods.
Key words: Uvaria purpurea; Annonaceae; heartwood; polyoxygenated cyclohexene; root growth inhibition
-19-
Note
Properties of an Extracellular Polysaccharide Produced by a Strain
of Enterobacter Isolated from Pond Water
Yuka ISOBE,・ Yuki MATSUMOTO, Kumio YOKOIGAWA, and Hiroyasu KAWAI
Department of Food Science and Nutrition, Nara Women′s University, Nara, 630-8506, Japan
Received November 24, 2000; Accepted January 28, 2001
A bacterium which was isolated from pond water and identified as Enterobacter cloacae produced a viscous extracellular polysaccharide when it was grown aerobically in a medium containing sucrose as a sole source of carbon. The maximum molecular weight of the polysaccharide was about 9.0×10＾{5}. The polysaccharide was composed of fucose, galactose, glucose, and glucuronic acid in a molar ratio of 2:3:2:1, but the molecular weight and the molar ratio of the sugar component were different from those of the polysaccharide produced by the same species reported elsewhere.
Key words: polysaccharide; Enterobacter cloacae
-20-
Note
Mulberry Moracins: Scavengers of UV Stress-generated Free Radicals
Rashmi SHARMA,1,2 Arun SHARMA,1 Tetsuya SHONO,3 Mitsuo TAKASUGI,3 Akira SHIRATA,1
Tatsuhito FUJIMURA,2 and Hiroaki MACHII1＊
1National Institute of Sericultural and Entomological Sciences (NISES), 1-2 Owashi, Tsukuba,
Ibaraki 305-8634, Japan
2Institute of Agricultural and Forest Engineering, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba,
Ibaraki 305-8537, Japan
3Department of Global Environmental Science, Hokkaido University, Sapporo 060-8589, Japan
Received November 27, 2000; Accepted January 9, 2001
Mulberry leaves treated with UV-C were found to accumulate three different phytoalexins, moracin C, moracin N, and chalcomoracin. The increased level of malondialdehyde in UV-treated leaves along with moracins suggested their role as a free-radical scavenger in stressed plants. All the three moracins induced under UV stress were capable of scavenging the superoxide anion generated by the xanthine-xanthine oxidase system. Also, moracins were capable of inhibiting lipid peroxidation, which strongly indicates their role as a scavenger.
Key words: free radical scavenger; moracins; mulberry; phytoalexins; UV stress
-21-
Note
Molecular Cloning and Characterization of cel2
from the Fungus Cochlibolus carbonum
Joong-Hoon AHN,1・ Paola SPOSATO,2 Su-Il KIM,3 and Jonathan D. WALTON2
1Department of Forest Resource, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701, Korea
2DOE-Plant Research Lab, Michigan State University, E. Lansing, MI 48824, USA
3School of Agricultural Biotechnology, Seoul National University, Suwon, Korea
Received November 27, 2000; Accepted January 30, 2001
A new cellulase gene, cel2, from the filamentous fungus Cochliobolus carbonum was cloned by using egl-1 of Trichoderma reesei as a heterologous probe. DNA blot analysis of cel2 showed that this gene is present as a single copy. The gene contains one 49-bp- intron. cel2 encodes a predicted protein (Cel2p) of 423 amino acids with a molecular mass of 45.8 kDa. The predicted pI is 4.96. It shows similarity to other endoglucanases from various fungi. From the comparison with other cellulase genes, cel2 belongs to family 7 of glucohydrolases. cel2 is located on a 2.5-Mb chromosome in C. carbonum and its expression is repressed by sucrose. A cel2 mutant of C. carbonum was created by transformation-mediated gene disruption. The pathogenicity of the mutant was indistinguishable from the wild type, indicating that cel2 by itself is not important for pathogenicity.
Key words: cellulase; Cochliobolus carbonum; pathogenicity
-22-
Note
Stronger Suppression of Plasma Cholesterol and Enhancement
of the Fecal Excretion of Steroids by a Buckwheat Protein Product
than by a Soy Protein Isolate in Rats Fed on a Cholesterol-free Diet
Hiroyuki TOMOTAKE,・ Iwao SHIMAOKA, Jun KAYASHITA, Fumiyo YOKOYAMA,
Misao NAKAJOH, and Norihisa KATO＊
Health Care Development, Kissei Pharmaceutical Co. Ltd., Matsumoto 399-8710, Japan
＊Department of Applied Biochemistry, Faculty of Applied Biological Science, Hiroshima University,
Higashi-Hiroshima 739-8528, Japan
Received December 6, 2000; Accepted January 18, 2001
We investigated the effects of a buckwheat protein product (BWP), soy protein isolate (SPI) and casein on the plasma cholesterol level and fecal steroid excretion in rats fed on a cholesterol-free diet. The consumption of BWP suppressed plasma cholesterol by enhancing the fecal excretion of both neutral and acidic steroids. These effects of BWP were stronger than those of SPI.
Key words: buckwheat protein; soy protein; cholesterol; fecal steroid; rat
-23-
Note
Effect of Dietary Histidine Content on the Change in Content of Skin Urocanic
Acid Isomers in Hairless Mice Irradiated with Ultraviolet B
Katsumi SHIBATA,・ Tsutomu FUKUWATARI, Satomi ZUSHI, and Etsuro SUGIMOTO
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 December 11, 2000; Accepted January 21, 2001
Hairless mice were fed with a 10％ amino acid mixture diet (control diet, 0.42％ histidine content), the control diet without histidine (histidine-free diet), or the control diet rich in histidine (histidine-rich diet; histidine content, 4.2％) for 32 days. They were irradiated with UV light of 312 nm for 30 min, and skin samples were periodically taken for measuring the urocanic acid isomers. Total urocanic acid isomers were decreased by UV irradiation in all the three groups, the recovery being the fastest in the histidine-rich group. The percentage increase in cis-urocanic acid/total urocanic acid was quickly increased by UVB irradiation. The recovery of the ratio was slightly higher in the histidine-rich group, although the total urocanic acid level was higher in the histidine-rich group than in the others. Therefore, the absolute cis-urocanic acid content in the skin was almost the same among the three groups. These results indicate that the increased histidine intake strengthened UVB protection without any decrease in immune suppression.
Key words: hairless mouse; urocanic acid; histidine; UV; skin
-24-
Note
Trehalose-producing Operon treYZ from Arthrobacter ramosus S34＊
Takuo YAMAMOTO,・ Kazuhiko MARUTA, Hikaru WATANABE, Hiroshi YAMASHITA,
Michio KUBOTA, Shigeharu FUKUDA, and Masashi KURIMOTO
Hayashibara Biochemical Laboratories, Inc., 7-7 Amase-minami machi, Okayama 700-0834, Japan
Received December 11, 2000; Accepted January 26, 2001
Arthrobacter ramosus S34, which produces trehalose from maltooligosaccharide, was isolated. A trehalose-producing operon, treYZ, was cloned from the genome. Expression experiments with treY and treZ confirmed that they coded malto-oligosyltrehalose synthase and malto-oligosyltrehalose trehalohydrolase, respectively. The amino acid sequence of TreY from A. ramosus S34 and that from Arthrobacter sp. Q36 did not show high identity, nor did those of TreZ.
Key words: trehalose; gene cloning; nucleotide sequence; operon; Arthrobacter
-25-
Note
Cloning and Expression of CitPDS1, a Gene Encoding
Phytoene Desaturase in Citrus
Masayuki KITA, Akira KOMATSU, Mitsuo OMURA, Masamichi YANO,
Yoshinori IKOMA, and Takaya MORIGUCHI1,・
Department of Citriculture, National Institute of Fruit Tree Science, Shimizu, Shizuoka 424-0292, Japan
Received December 12, 2000; Accepted February 5, 2001.
A cDNA clone encoding phytoene desaturase (PDS) was isolated from citrus (Citrus unshiu Marc.). The transcript of the isolated PDS (CitPDS1) was not detected by conventional RNA gel-blot analysis; instead, it was detected by a sensitive reverse transcription-PCR (RT-PCR). The CitPDS1 transcript in the juice sacs/segment epidermis (edible part) was at a low level in the young fruit, and it increased toward maturation like citrus phytoene synthase (CitPSY1). In the peel, in contrast to CitPSY1, the transcript of which was induced toward maturation, the level of the CitPDS1 transcript remained constant after an increase in July, indicating non-coordinate regulation of CitPDS1 and CitPSY1 in the peel.
Key words: carotenoid accumulation; cDNA cloning; phytoene dasaturase; mRNA expression; RT-PCR
-26-
Note
New Synthesis of Serricornin, the Female Sex Pheromone
of the Cigarette Beetle・
Ken FUJITA and Kenji MORI・・
Department of Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3,
Shinjuku-ku, Tokyo 162-8601, Japan
Received December 13, 2000; Accepted January 19, 2001
Serricornin [(4S,6S,7S)-7-hydroxy-4,6-dimethyl-3-nonanone], the female sex pheromone of Lasioderma serricorne, was synthesized by starting from (2S,4S)-2,4-dimethyl-1,5-pentanediol that had been obtained by lipase-catalyzed enantiomer separation of its racemate.
Key words: asymmetric synthesis; cigarette beetle; pheromone; serricornin
-27-
Note
Antifeedants against Acusta despesta from the Japanese Cedar,
Cryptomeria japonica II
Xiao Hui CHEN, Chul-Sa KIM,＊ Takehiro KASHIWAGI, Shin-ichi TEBAYASHI,
and Michio HORIIKE
Department of Bioresources Science, Faculty of Agriculture, Kochi University, B200 Monobe,
Nankoku 783-8502, Japan
Received December 27, 2000; Accepted January 17, 2001
The hexane-soluble fr. was found to be as intense in antifeeding activity as the crude methnol extract of Cryptomeria japonica against Acusta despesta. This hexane soluble-fraction was used to isolate and identify two sesquiterpenols, (−)-cubebol and (+)-2,7(14),10-bisabolatrien-1-ol-4-one, as the active compounds. Both compounds strongly inhibited the feeding behavior of A. despesta at 120 μg/cm＾{2} and 80 μg/cm＾{2} concentrations, respectively.
Key words: Antifeedant; Cryptomeria japonica; Acusta despesta; (--)-cubebol; (+)-2,7(14),10-bisabolatrien-1-ol-4-one
-28-
Preliminary Communication
Occurrence of the Major Food Allergen, Ovomucoid, in Human Breast Milk
as an Immune Complex
Junko HIROSE,1 Setsuko ITO,2 Noriko HIRATA,3 Shoko KIDO,3 Naofumi KITABATAKE,1
and Hiroshi NARITA3,・
1Research Institute for Food Science, Kyoto University, Uji 611-0011, Japan
2Department of Food Science and Nutrition, Faculty of Human Life and Science, Doshisha Women′s College
of Liberal Arts, Kyoto 602-0893, Japan
3Department of Food and Nutrition, Kyoto Women′s University, Kyoto 605-8501, Japan
Received November 20, 2000; Accepted February 20, 2001
The major food allergen, ovomucoid (molecular weight of 28 kDa) could be detected in 12 of 37 human breast milk samples by using three types of enzyme-linked immunosorbent assay. By gel-filtration, ovomucoid in breast milk was only eluted in the fractions corresponding to a molecular weight of about 450 kDa, suggesting its occurrence as an immune complex with IgA. In fact, almost the same elution profile as that for ovomucoid was obtained for its immune complex with IgA by gel-filtration.
Key words: human breast milk; ovomucoid; food allergy; monoclonal antibody; secretory IgA
-29-
Preliminary Communication
Inhibitory Effect of Monoacylglycerol on Fatty Acid Uptake
into Rat Intestinal Epithelial Cells
Kaeko MUROTA,・ Noriko MATSUI, Teruo KAWADA, Nobuyuki TAKAHASHI,
and Tohru FUSHUKI・・
Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School
of Agriculture, Kyoto University, Kyoto 606-8502, Japan
Received December 25, 2000; Accepted March 19, 2001
We investigated the influence of glycerol esters on oleic acid uptake into IEC-6 cells. Monoolein, especially 2-monoacylglycerol, significantly inhibited the cellular uptake. Although diolein slightly inhibited the oleic acid uptake, triolein, glycerol and monooctanoate had no effect. These results suggest that after lipid digestion in the intestine, long-chain fatty acid uptake may be influenced by another digestive product, 2-monoacylglycerol.
Key words: long-chain fatty acid; monoacylglycerol; intestinal absorption; IEC-6
-30-
Preliminary Communication
Oxidation of Bisphenol A and Related Compounds
Mitsuru YOSHIDA,・ Hiroshi ONO, Yoshiko MORI, Yoshihiro CHUDA,＊ and Koichi ONISHI＊
National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan
＊Center for Food Quality, Labeling and Consumer Services, 1-21-2 Kitabukuro-cho, Saitama 330-9731, Japan
Received February 1, 2001; Accepted March 13, 2001
Bisphenol A was oxidized to monoquinone and bisquinone derivatives by Fremy′s salt, a radical oxidant, though salcomine and alkali did not catalyze the oxidation by molecular oxygen. Bisphenol A, bisphenol B, and 3,4?-(1-methylethylidene)bisphenol were converted to their monoquinone derivatives in the presence of tyrosinase at 25°C at pH 6.5, but not to the bisquinone derivatives under these conditions.
Key words: Fremy′s salt; tyrosinase; quinone; bisphenol B; 3,4?-(1-methylethylidene)|||bisphenol