Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 60 , Issue 7
Showing 1-39 articles out of 39 articles from the selected issue
  • Masayuki SHIMAO, Tomoyuki NAKAMURA, Akira OKUDA, Shigeaki HARAYAMA
    1996 Volume 60 Issue 7 Pages 1051-1055
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    A soil isolate, Pseudomonas putida strain A10L that utilizes mandelate via the mandelate pathway was mutagenized by transposon Tn5-Mob insertion and a mutant 168 lacking mandelate racemase (MR) and a mutant 254 lacking benzoylformate decarboxylase (BFDC) were obtained. Expression of (S)-mandelate dehydrogenase (MDH), BFDC, NAD+-dependent benzaldehyde dehydrogenase (BDH) and NADP+-dependent BDH in the MR-lacking mutant was not affected by the insertion, and it was inducible similarly to the wild type strain. On the other hand, expression of MR and MDH in the BFDC-lacking mutant was low and constitutive, and NAD+- and NADP+-dependent BDHs were produced at a rather high level under non-induced conditions by the mutant. Genes for MR (mdlA), MDH (mdlB), and BFDC (mdlC) were indicated to be organized in an operon in the order of mdlCBA. Optical resolution to obtain (R)-mandelate, a useful synthon for pharmaceuticals, was shown to be performed with the MR-lacking mutant.
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  • Masayuki SHIMAO, Tsuyoshi TAMOGAMI, Koichi NISHI, Shigeaki HARAYAMA
    1996 Volume 60 Issue 7 Pages 1056-1062
    Published: July 23, 1996
    Released: February 08, 2008
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    A gene library of poly(vinyl alcohol) (PVA)-degrading Pseudomonas sp. strain VM15C was constructed in Escherichia coli with the vector pUC18. Screening of this library with a Chromogenic PVA dehydrogenase assay resulted in the isolation of a clone that carries the gene (pdh) for the PVA dehydrogenase, and the entire nucleotide sequence of its structural gene was determined. The gene encodes a protein of 639 amino acid residues (68, 045 Da) and in the deduced amino acid sequence, some putative functional sites, a signal sequence, a heme c-binding site, and a PQQ-binding site, were detected. The amino acid sequence showed low similarity to other types of quinoprotein dehydrogenases. PVA dehydrogenase expressed in E. coli clones required PQQ. Ca2+, and Mg2+ stimulated the activity. PVA-dependent heme c reduction occurred with exogenous PQQ in cell extracts of the E. coli clone. The PVA dehydrogenase in the E. coli clone was localized in the cytoplasm.
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  • Susumu ANDO, Kozaburo MIKATA, Yasutaka TAHARA, Yuzo YAMADA
    1996 Volume 60 Issue 7 Pages 1063-1069
    Published: July 23, 1996
    Released: February 08, 2008
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    In order to clarify the phylogenetic relationships of the species classified in the genus Kluyveromyces (Saccharomycetaceae), three partial base sequences of 18S and 26S rRNAs of eighteen strains were determined. The regions determined of the strains corresponded to positions 1451 through 1618 (168 bases) of 18S rRNA and to positions 1611 through 1835 (225 bases) and 493 through 622 (130 bases) of a strain (IFO 2376) of Saccharomyces cerevisiae. The analyses of the partial base sequences suggested that the genus Kluyveromyces is phylogenetically heterogeneous, ranging from the strains that are quite close to the strain of S. cerevisiae to the strains that are distinct enough to be classified in genera separate from the genus Saccharomyces. From our sequence data, we concluded that the extent of the genus Kluyveromyces should be restricted to only one species, K. polysporus, the type species of the genus. Kluyveromyces phaffii was also distinct enough to deserve another genus. Kluyveromyces cellobiovorus was not close to any of the strains of Kluyveromyces species examined, and should be excluded from the genus. Most of the strains of the species examined were fairly close to the strain of S. cerevisiae.
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  • Susumu ANDO, Kozaburo MIKATA, Yasutaka TAHARA, Yuzo YAMADA
    1996 Volume 60 Issue 7 Pages 1070-1075
    Published: July 23, 1996
    Released: February 08, 2008
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    In order to clarify the phylogenetic relationships among the yeast species classified in the genus Saccharomyces, partial base sequences of 18S and 26S ribosomal RNAs were determined for ten selected strains. The regions determined correspond to positions 1451 through 1618 of the 18S rRNA and positions 493 through 622 and 1611 through 1835 of the 26S rRNA in S. cerevisiae. Analyses of these partial base sequences suggested that the genus Saccharomyces is phylogenetically heterogeneous. Saccharomyces servazzii and S. unisporus showed identical or very similar sequences in all the three regions, and their phylogenetic distance from S. cerevisiae was large enough to introduce a genus independent of Saccharomyces. Saccharomyces kluyveri is also distant from all the other Saccharomyces species examined, and is likely to deserve a new genus. Estimated phylogenetic relationships between Saccharomyces and other genera characterized by the Q-6 system, such as species of Zygosaccharomyces, Torulaspora, Kluyveromyces, Arxiozyma, Pachytichospora, Nadsonia, Hanseniaspora, Kloeckeraspora, and Saccharomycodes, are also discussed.
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  • Hiromasa KIYOTA, Tadateru MASUDA, Jun CHIBA, Takayuki ORITANI
    1996 Volume 60 Issue 7 Pages 1076-1080
    Published: July 23, 1996
    Released: February 08, 2008
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    Abscisic acid (ABA) is easily isomerized to inactive trans-ABA by light. To solve this problem, two variations of epoxy-β-ionylideneacetic acid were synthesized as ABA analogs, each of them having a methoxycarbonyl or a fluoric substituent at the 2-position. The 2E-, and 2Z-fluorinated analogs showed moderate growth inhibitory activity toward rice seedlings and lettuce seeds, whereas the methoxycarbonyl analog was inactive toward rice seedling growth and only partially active toward lettuce germination. The 2E-fluorinated analog was extensively isomerized to the 2Z-isomer by UV irradiation. We think that a steric requisite for the 2E-position was high, and that the fluorine substituent was not effective for fixing the 2-double bond in the E-configuration.
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  • Takeshi YAMAGAMI, Gunki FUNATSU
    1996 Volume 60 Issue 7 Pages 1081-1086
    Published: July 23, 1996
    Released: February 08, 2008
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    By a limited proteolysis with thermolysin, rye seed chitinase-a (RSC-a) was separated into a N-terminal cysteine-rich chitin-binding (CB-) domain (48 residues) and a catalytic (Cat-) domain (254 residues). The hydrolytic activity of the isolated Cat-domain toward soluble glycolchitin, was similar to that of RSC-a, but that toward insoluble colloidal chitin was 28% of that of RSC-a. Five disulfide bonds in the CB-domain were reduced with 2-mercaptoethanol (2-ME) in the absence of denaturing agents by an "all-or-none" process, that is, once the disulfide bond between Cys15 and Cys42 in the CB-domain was cleaved, the remaining four disulfide bonds were reduced very easily. The reduced and carboxymethylated RSC-a completely lost the chitin-binding ability, but retained 50% of the hydrolytic activity toward colloidal chitin of RSC-a.From these results, it was shown that RSC-a consists of a CB-domain and a Cat-domain connected by a flexible linker, and it was suggested that the CB-domain increases the hydrolytic action of Cat-domain toward insoluble chitin derivatives by binding to them.
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  • Hideki OISHI, Shinji TSUDA, Yasuo WATANABE, Youichi TAMAI
    1996 Volume 60 Issue 7 Pages 1087-1092
    Published: July 23, 1996
    Released: February 08, 2008
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    Phospholipase B from Schizosaccharomyces pombe was purified by ammonium sulfate fractionation and chromatographed on phenyl-Sepharose CL-4B, DEAE-Toyopearl 650M, and TSK gel G4000SW columns. The purified enzyme was a glycoprotein with molecular weight of approximately 300, 000 and 100, 000-150, 000 by gel filtration and SDS-polyacrylamide gel electrophoresis, respectively. The isoelectric point was pH 4.7. The optimum pH of the enzyme was 2.5 and no activity was detected at neutral and alkaline pHs. The enzyme was not heat-stable. Enzyme activity was slightly stimulated by divalent ions except Fe2+ and 0.1% sodium deoxycholate, and inhibited by Fe2+, Fe3+, 0.1% sodium dodecyl sulfate, and 0.01% cetyltrimethylammonium bromide. The enzyme hydrolyzed mono- and diacylphospholipids, and phosphatidylinositol was hydrolyzed most preferentially. Triglyceride was not hydrolyzed. The enzyme also had acyltransferase activity on lysophosphatidylcholine, forming the corresponding diacylphosphatidylcholine.
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  • Masahiro TADA, Risa MATSUMOTO, Harutaka YAMAGUCHI, Kazuhiro CHIBA
    1996 Volume 60 Issue 7 Pages 1093-1095
    Published: July 23, 1996
    Released: February 08, 2008
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    Two novel antioxidants (vinyl caffeate and trans-p-menth-8-en-7-yl caffeate) and seven known antioxidants (3, 4-dihydroxybenzaldehyde, methyl 3, 4-dihydroxy-benzoate, methyl caffeate, 3', 4', 5, 7-tetrahydroxy-flavone, caffeic acid, 6, 7-dihydroxycoumarin, and rosmarinic acid) were isolated from Perilla frutescens Britton var. crispa (Thunb.). The redox potentials of the novel isolated antioxidative compounds were comparable to those of known antioxidants. trans-p-Menth-8-en-7-yl caffeate was effective to prevent the oxidative degradation of perillaldehyde in the essential oil of P. frutescens.
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  • Kazushige YOKOTA, Toru MORISHIMA, Tsutomu NAGAYA, Mitsuo JISAKA, Koich ...
    1996 Volume 60 Issue 7 Pages 1096-1103
    Published: July 23, 1996
    Released: February 08, 2008
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    Madin-Darby canine kidney (MDCK) cells were modified with dietary unsaturated fatty acids. The effects on the fatty acid composition in each phospholipid class and the formation of prostanoids upon stimulation were studied, from which the specificity of metabolism of individual unsaturated fatty acids and the regulation of arachidonate cascades in the modified cells were discussed. C18 unsaturated fatty acids were preferentially incorporated into phosphatidylcholine (PC) over phosphatidylethanolamine (PE), but arachidonic acid (20:4(n-6)) derived from γ-linolenic acid (18:3(n-6)) was much more predominant in PE than PC. The fatty acid level in PE ranged from about 26-28% when the cells were modified with 20:4(n-6) or 5, 8, 11, 14, 17-eicosapentaenoic acid (20:5(n-3)), indicating the limitation of the storage of the eicosapolyenoic acids. The extra amounts appeared to be stored in PC. 18:3(n-6) was comparable to 20:4(n-6) to raise the level of 20:4(n-6) in PE, but not in PC which had half of 20:4(n-6) in PE. The supplementation of linoleic acid (18:2(n-6)), 18:3(n-6), and 20:4(n-6) caused significant increases in the synthesis of prostaglandin (PG)E2 up to almost the same levels when the modified cells were stimulated with 50 nM PMA and 100 nM A23187 for 24 h. The cultured cells modified with eicosapolyenoic acids including 20:3(n-6), 20:4(n-6), and 20:5(n-3) were found to be inhibitory for the induction of PGE2 synthetic activity involving de novo synthesis of PG endoperoxide synthase, suggesting negative feedback regulation of the modified cells.
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  • Toshiko KUNIKATA, Shigenori NISHIMURA, Yasunori NITTA
    1996 Volume 60 Issue 7 Pages 1104-1108
    Published: July 23, 1996
    Released: February 08, 2008
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    The inhibition of hydration of maltal (α-D-glucopyranosyl-(1→4)-2-deoxy-D-glucal) catalyzed by soybean β-amylase with 4-O-α-D-glucopyranosyl-(1→4)-1-deoxynojirimycin (GDN) was investigated at 25°C and at pH 5.4. As the concentrations of GDN used were comparable to that of the enzyme, Henderson's treatment was applied to this system. It was found that two maltal molecules bind to the enzyme according to a random mechanism and GDN inhibits the hydration of maltal competitively at subsites 1 and 2, and noncompetitively at the other site. On the basis of this result, it was inferred that the role of the mobile loop of this enzyme is to create a convenient catalytic environment for the hydration, and the closing of the active site by the mobile loop is induced by the binding of maltal.
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  • Akira KURISAKI, Hiroshi SAGAMI, Kyozo OGURA
    1996 Volume 60 Issue 7 Pages 1109-1114
    Published: July 23, 1996
    Released: February 08, 2008
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    Pig testicular dehydrodolichyl diphosphate synthase was released in a soluble form out of microsomes by controlled proteolysis with trypsin or papain. Approximately 25% of the microsomal enzyme activity was recovered in the 115, 000×g supernatant fraction when the microsomes were treated with trypsin at 4°C for 1 h. Similar proteolytic release of microsomal enzyme was also observed with the treatment with papain. The Km, optimal pH, Mg2+ dependency, and ion strength dependency of the enzyme released by trypsin were similar to those of the microsomal enzyme. The microsomal enzyme was active even in the absence of detergents, while the released enzyme required detergents for activity. Gel filtration of the released enzyme gave a peak of dehydrodolichyl diphosphate synthase activity, which appeared between 150-kDa and 50-kDa molecular mass markers.
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  • Yoshiki HAYASHI, Nobuhiro ISHIHARA, Motohisa TAKAHASHI, Eiji FUJII, Ka ...
    1996 Volume 60 Issue 7 Pages 1115-1117
    Published: July 23, 1996
    Released: February 08, 2008
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    A new cytotoxic compound 2 was isolated from a water extract of corn germ. Structural elucidation by spectroscopic data and chemical evidence fully substantiated 2 to be 11(E)-10-oxo-11-octadecen-13-olide. Compound 2 exhibited considerably strong cytotoxic activity against various cell lines with IC50 of 0.9-2.8 μg/ml.
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  • Mikio FUJII, Yuko NAGAOKA, Shigeyuki IMAMURA, Toshio SHIMIZU
    1996 Volume 60 Issue 7 Pages 1118-1122
    Published: July 23, 1996
    Released: February 08, 2008
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    An EDTA-insensitive prolidase (proline dipeptidase, EC 3.4.13.9) was isolated from a cell-free extract of Aureobacterium esteraromaticum IFO 3752. The enzyme was purified almost to homogeneity using acetone precipitation, hydrophobic chromatography, ion-exchange chromatography, and gel-permeation chromatography. The enzyme has a molecular weight of about 440, 000 by gel permeation chromatography, and about 40, 000 by SDS polyacrylamide gel electrophoresis. The isoelectric point was 4.6. The enzyme hydrolyzed aminoacylprolines such as Ser-Pro, Thr-Pro, Gly-Pro, Ala-Pro, Ile-Pro, Leu-Pro, and Pro-Pro. It also hydrolyzed Gly-Hyp and Pro-Hyp. The rate of hydrolysis for Pro-Hyp was the highest among the substrates tested. Optimum pH for hydrolyzing Pro-Hyp was 9.0 and the enzyme was stable in the pH range from 5 to 10. The optimum temperature was estimated to be 45°C using 10 min of reaction. At least 90% of the initial activity remained after 30 min of incubation at 60°C. p-Chloromercuribenzoic acid and o-phenanthrolin inhibited the enzyme's activity while EDTA did not. Addition of Mn2+ ion did not stimulate activity. These results suggest either that the metal ion in the enzyme may be tightly bound to the polypeptide chain, or that the enzyme is not a metallo-enzyme but a thiol-enzyme.
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  • Masaya OHTA, Shinichi EMI, Hiroyuki IWAMOTO, Junzo HIROSE, Keitaro HIR ...
    1996 Volume 60 Issue 7 Pages 1123-1130
    Published: July 23, 1996
    Released: February 08, 2008
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    Ascorbate oxidase from the fungus Acremonium sp. HI-25 is a copper-containing glycoprotein that catalyzes the oxidation of ascorbic acid to dehydroascorbic acid. Monosaccharide composition analysis showed that the enzyme contains exclusively N-linked oligosaccharide chains. Following liberation by hydrazinolysis/re-N-acetylation, and fractionation by HPLC on anion exchange, Amide-80 and/or octadecyl silica columns after derivatization with p-aminobenzoic ethyl ester, the structures of the twelve major neutral oligosaccharides were identified by FAB-MS, 400MHz 1H-NMR, methylation analysis, mild acid hydrolysis, and/or sequential exoglycosidase digestions. Acremonium sp. ascorbate oxidase was found to consist of high-mannose type oligosaccharides (76.3%) having 4 to 9 mannose residues and a series of novel D-galactofuranose-containing high-mannose type oligosaccharides (18.6%) with the following structure.[chemical formula]
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  • Sylvain GUYOT, Patrice PELLERIN, Jean-Marc BRILLOUET, Veronique CHEYNI ...
    1996 Volume 60 Issue 7 Pages 1131-1135
    Published: July 23, 1996
    Released: February 08, 2008
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    The sensitivity and specificity of the inhibition of β-glucosidase (Amygdalae dulces) by (+)-catechin, an oxidized (+)-catechin solution, three dimeric procyanidins, and five (+)-catechin dimers obtained by enzymatic oxidation were evaluated by using a chromatographic method. All the polyphenols tested presented a significant inhibitory effect. Non-competitive inhibition was observed for the oxidized (+)-catechin solution. Some oxidation products were at least as powerful inhibitors as procyanidins which are known for their tanning effect. Yellow oxidation products were among the strongest inhibitors. No marked role of the number of hydroxyl and o-diphenol groups nor of the nature or position of the interflavanic linkage in the inhibitory effect was apparent.
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  • Chikaku DOGASAKI, Motohiro NISHIJIMA, Naohito OHNO, Toshiro YADOMAE, T ...
    1996 Volume 60 Issue 7 Pages 1136-1139
    Published: July 23, 1996
    Released: February 08, 2008
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    Polyclonal antibodies against P-1, a pectic polysaccharide fraction extracted with 0.5M NaOH from the kernels of Prunus mume and consisted of arabino-galacturonan, and I-3, the partial acid (0.1M trifluoroacetic acid) hydrolysate of P-1, were prepared in Japanese white rabbits. Competitive ELISA experiments strongly suggested that anti P-1 and anti I-3 antibodies were different but P-1 and I-3 cross-reacted with each other to recognize a partly similar epitope structure. The reactivities of polysaccharide fractions from the raw flesh of P. mume, and the kernels of apricot and peach extracted with either water or sodium hydroxide were examined using both antisera by the indirect competitive ELISA method. The polysaccharide fractions extracted with sodium hydroxide Solutions had the reactivities but not those extracted with cold and hot water. These facts suggested that the similar structure of polysaccharides to P-1 was present in the flesh of P. mume and the kernels of apricot and peach. However, neither pectin of apple nor citrus had reactivity with each antiserum. P-1 would be different in chemical structure from a commercially available pectin, a Water-soluble polysaccharide from apple and citrus.
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  • Rikizo AONO, Takafumi SANADA, Koki HORIKOSHI
    1996 Volume 60 Issue 7 Pages 1140-1145
    Published: July 23, 1996
    Released: February 08, 2008
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    Cells of the facultative alkaliphile Bacillus sp. C-125 grown at neutral pH autolyze rapidly in alkaline buffers of pH 9-10. Alkaline autolytic activity has been found mainly in the cell wall fraction. A peptidoglycan lytic enzyme was extracted from the cell wall fraction suspended in 4M LiCl. The enzyme was identified as N-acetylmuramyl-L-alanine amidase, with a molecular mass of 58kDa. At low salinity, the enzyme formed an aggregate of high molecular mass. The peptidoglycan lytic reaction of this enzyme happened at pH 9.0-10.5 at 37°C. Optimum pH for the reaction was 9.7-10.0. The enzyme was most active at 60°C when assayed at pH 9.0.
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  • Rikizo AONO, Noriyuki DOUKYU
    1996 Volume 60 Issue 7 Pages 1146-1151
    Published: July 23, 1996
    Released: February 08, 2008
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    Pseudomonas sp. strain ST-200 isolated from a humus soil effectively oxidizes cholesterol dissolved in organic solvents but not that suspended in the growth medium. The organism does not assimilate cholesterol. This organism oxidized a variety of 5α- or 5-ene-sterols dissolved in organic solvent. First, the 3β-OH group was oxidized to a ketone group. The 3α-OH group was scarcely oxidized. Successively, C-6 position of 5-ene-steroids was hydroxylated, and a double bond of 5-ene-steroids was transferred from Δ5 to Δ4. Then, the 6-OH group was oxidized to a ketone group. Persolvent fermentation with ST-200 would provide an effective, convenient, and stereospecific method to oxidize the C-3 and C-6 positions of steroids.
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  • Hiroko OSHITE, Motoko ODA, Van Chuyen NGUYEN
    1996 Volume 60 Issue 7 Pages 1152-1155
    Published: July 23, 1996
    Released: February 08, 2008
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    The mutagenicity and desmutagenicity of extracts of soybeans heated at 225±5°C were investigated by the Ames test. The soybeans were refluxed in water, methanol, or diethylether for 2h. The aqueous and methanol extracts (2-4 mg/plate) of the heated soybeans exhibited strong desmutagenic activity of 43-92% against heterocyclic amines (Trp-P-1, Glu-P-2, IQ, MeIQx, PhIP), while no mutagenicity was observed. The desmutagenicity of the heated soybean extracts remained even after denaturation by 0.1 N HCl in vitro and absorption by the rat small intestine. The desmutagenic mechanism for heated soybeans was evaluated, and it was verified that the soybean extract exhibited its desmutagenicity by blocking the mutagenicity of activated Trp-P-1, and not by inhibiting the S9 enzyme system.
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  • Kaoru TAKEGAWA, Naotaka TANAKA, Mitsuaki TABUCHI, Shojiro IWAHARA
    1996 Volume 60 Issue 7 Pages 1156-1159
    Published: July 23, 1996
    Released: February 08, 2008
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    N-Linked oligosaccharides were elongated by glycosylation with mannose and galactose residues in the secretory pathway of Schizosaccharomyces pombe. The wild-type S. pombe cells were agglutinated by the additions of not only concanavalin A lectin, which is specific for mannose residues, but also PNA (from Arachis hypogaea) and RCA (Ricinus communis) lectins, which are specific for terminal galactose residues. By PNA-binding selection, we isolated an S. pombe mutant defective in protein glycosylation. The mutant cells, named gms1, were not agglutinated by PNA or RCA. In contrast, agglutination of the gms1 cells by the addition of concanavalin A was markedly increased. Structural studies on N-linked oligosaccharides from gms1 mutant cells showed that the number of α-1, 2-linked galactose residues was markedly reduced, and unsubstituted α-1, 6-linked polymannose outer chains were attached to the core oligosaccharides.
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  • Takashi TACHIKI, Takeshi YAMADA, Masashi UEDA, Yasuki NAEMURA, Nobuo I ...
    1996 Volume 60 Issue 7 Pages 1160-1164
    Published: July 23, 1996
    Released: February 08, 2008
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    Glutaminase (EC 3.5.1.2) was isolated from Pseudomonas nitroreducens IFO 12694 grown on 0.6% sodium glutamate as a nitrogen source (325-fold purification, 13% yield). The molecular weight of the enzyme was estimated to be 40, 000 by gel filtration and SDS-gel electrophoresis. The enzyme hydrolyzed glutamine optimally at pH 9, and its Km was 6.5mM. D-Glutamine, γ-glutamyl p-nitroanilide, γ-glutamylmethylamide, γ-glutamylethylamide (theanine), and glutathione showed respectively 107, 85, 78, 74, and 82% reactivity of glutamine. Zn2+, Ni2+, Cd2+, Co2+, Fe2+, and Cu2+ repressed the enzyme activity strongly. Glutaminase formed γ-glutamylhydroxamate in the reaction mixture containing glutamine and hydroxylamine (transferring reaction). The optimum pH of the transferring reaction was 7-8, and the Km for glutamine and hydroxylamine were 4mM and 120 mM, respectively. γ-Glutamyl derivatives hydrolyzable by glutaminase showed reactivity for the transferring reaction. Methylamine or ethylamine was replaceable for hydroxylamine with 3 or 8% reactivity. The effect of divalent cations was not so striking as in the hydrolyzing reaction.
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  • Tomotada ONO, Motoyoshi TAKEDA, Guo SHUNTANG
    1996 Volume 60 Issue 7 Pages 1165-1169
    Published: July 23, 1996
    Released: February 08, 2008
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    The protein in soybean milk exists as 11S and 7S globulins, and the particles formed from them. The lipid content and composition in the protein fractions and effects of defatting on the form of the protein particles were investigated. The size-distribution of protein particles in both raw and heated soybean milk (soymilk) was not influenced by defatting with hexane, but the number of large particles were slightly increased. The protein particles from raw and heated soymilk samples contained 60% and 37% of the total lipid, respectively. Almost all neutral lipid in the particles of raw soymilk was moved to a floating fraction by heating, but a half of the phospholipids was retained in the particles. The protein components from the hexane-defatted meal were similar to those from whole meal, but those from the C-M-de-fatted meal contained remarkably little β-Conglycinin. C-M-de-fatting (Removal of polar lipids) caused a reduction in the particulate fraction, and the addition of phospholipids (lecithin) promoted the formation of protein particles.
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  • Masahiro KOHASHI, Ken-ichi TANAKA, Tatsuo WATANABE
    1996 Volume 60 Issue 7 Pages 1170-1172
    Published: July 23, 1996
    Released: February 08, 2008
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    Non-thermal effects of ceramics irradiation on dissociation state of twenty L-aminio acids have been investigated. Dissociation constants of the amino acids other than His and Glu varied by a 3-h irradiation under cooling. pK's of α-carboxyl group of amino acids having longer side chains on the α-carbon were decreased by the irradiation. Although pK's of α-amino group of Arg, Lys, Asp, and CySH were decreased by the irradiation and pK of Tyr was increased, pK's of the other fifteen amino acids were not affected. Although the isoelectric points of Lys, Arg, Trp, Asp, and CySH were decreased by the irradiation, those of the other fifteen Amino acids were not affected. It was suggested that various changes in pH of amino acids in aqueous solution and dissociation state of the functional groups will be caused from stimulation by the irradiation and stabilization of the hydration layer around amino acids.
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  • Makoto ABE, Chieko DOMOTO, Hirohito WATANABE, Keiko ABE, Soichi ARAI
    1996 Volume 60 Issue 7 Pages 1173-1175
    Published: July 23, 1996
    Released: February 08, 2008
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    A genomic DNA clone encoding corn cystatin, a cysteine proteinase inhibitor of corn, was isolated from a λEMBL3 phage genomic library. The genomic DNA clone spans approximately 2.2 kb and consists of three exons and two introns. The exon number and the intron breakpoints coincide with those of the genes for two types of oryzacystatin.
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  • Takashi KOMETANI, Yoshinobu TERADA, Takahisa NISHIMURA, Takashi NAKAE, ...
    1996 Volume 60 Issue 7 Pages 1176-1178
    Published: July 23, 1996
    Released: February 08, 2008
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    Cyclodextrin glucanotransferase [1, 4-α-D-glucan 4-α-D-(1, 4-α-D-glucano)-transferase (cyclizing), EC 2.4.1.19] from an alkalophilic Bacillus species A2-5a had a wider acceptor specificity than that from B. macerans, which was similar to those from B. stearothermophilus and B. circulans. Glucosyl rhamnose produced by the CGTase was identified as glucopyranosyl-α-1, 4-rhamnopyranose by α- and β-glucosidase treatments, and 1H- and 13C-NMR analyses.
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  • Tomoki HAMAMOTO, Toshitada NOGUCHI, Yuichiro MIDORIKAWA
    1996 Volume 60 Issue 7 Pages 1179-1180
    Published: July 23, 1996
    Released: February 08, 2008
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    The purine nucleoside phosphorylase (Pu-NPase) and the pyrimidine nucleoside phosphorylase (Py-NPase) have been purified from Bacillus stearothermophilus TH 6-2. The Pu-NPase is a trimer of 30-kDa subunits and the Py-NPase is a dimer of 46-kDa subunits. The isoelectric points of Pu-NPase and Py-NPase were pH 4.3 and 4.6, respectively. The Pu-NPase could catalyze the phosphorolysis of inosine and guanosine, but not adenosine. The Py-NPase could phosphorolyze both uridine and thymidine.
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  • Hiroshi HOSOYAMA, Akio OBATA, Noriko BANDO, Hideaki TSUJI, Tadashi OGA ...
    1996 Volume 60 Issue 7 Pages 1181-1182
    Published: July 23, 1996
    Released: February 08, 2008
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    The epitopes of the major soybean allergen, Gly m Bd 30K, recognized by mouse monoclonal antibodies H6 and F5 were investigated by using synthetic peptides bound to pins. The epitopes are shown to be localized in Peptide 31QGGCGRGWAFSATGAIEA48 for H6, and in 115DKVTIDGYETLIMSDEST132 for F5.
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  • Goro TAKADA, Shuichi KARITA, Asako TAKEUCHI, Md. Mainul AHSAN, Tetsuya ...
    1996 Volume 60 Issue 7 Pages 1183-1185
    Published: July 23, 1996
    Released: February 08, 2008
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    Clostidium stercorarium xylanase A (XynA) composed of a family 11 catalytic domain of glycosyl hydrolases and family VI CBDs bound to amorphous cellulose, i.e., acid-swollen cellulose (ASC), but not highly crystalline cellulose, and it was released from the cellulose protein complex by wash with a cellobiose solution. The Ka and [PC]max values of ASC were 0.25 liter/μmol and 26 μmol/g.
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  • Hideki KAWASHIMA, Satoshi OGAWA
    1996 Volume 60 Issue 7 Pages 1186-1187
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    5, 10-Dihydrophenazine (H2Phen) was formed from phenazine (Phen) by Pseudomonas cepacia IFO 15124 in growing cultures at low oxygen tensions. Effects of culture conditions on microbial reduction of Phen with this strain were investigated. Under optimized conditions, the transformation of Phen to H2Phen by this strain gave the molar conversion yield of 30%. However, H2Phen was not detected in the culture medium when the strain was incubated with Phen with sufficient aeration.
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  • Tatsuma MORI, Michio SAKIMOTO, Takashi KAGI, Takuo SAKAI
    1996 Volume 60 Issue 7 Pages 1188-1190
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    Geotrichum sp. WF9101 isolated from a poly(vinyl alcohol)-degrading mixed culture could utilized vinyl alcohol oligomers, but not the polymers. This strain is proposed to have utilized degradation products of poly(vinyl alcohol) in the mixed culture. Biodegradation of vinyl alcohol oligomers by this strain was discussed using 2, 4-pentanediol as a model substrate.
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  • Tatsuma MORI, Michio SAKIMOTO, Takashi KAGI, Takuo SAKAI
    1996 Volume 60 Issue 7 Pages 1191-1192
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    Geotrichum sp. WF9101 could degrade (S)-(+)-1, 2-propanediol, (S)-(+)-1, 3-butanediol, and (2S, 4S)-(+)-2, 4-pentanediol, but not the corresponding enantiomers. An NAD+-linked secondary alcohol dehydrogenase purified from the strain showed the same enantioselective oxidations towards these diols. This enzyme is proposed to be useful for the preparation of (R)-(-)-diols from the racemates of these diols.
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  • Kunio IMAI, Hitoshi OBATA, Keisuke SHIMIZU, Takashi KOMIYA
    1996 Volume 60 Issue 7 Pages 1193-1194
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    Cadystins induced in a fission yeast treated with Cd2+ are the higher homologs of glutathione. In the present work, glutathione was incubated with Carboxypeptidase Y at a high substrate concentration. The reaction afforded not only the degraded product, but also cadystins and their analogs. A possible transformation pathway for glutathione by this enzyme is proposed.
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  • Mitsuhiro UEDA, Minoru SHIRO, Takashi KAWAGUCHI, Motoo ARAI
    1996 Volume 60 Issue 7 Pages 1195-1197
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    The chitinase III gene of Aeromonas sp. No. 10S-24 was expressed in Escherichia coli. Production of chitinase III by E. coli was 3-fold higher than that of chitinases in the culture supernatant of Aeromonas sp. The enzyme from E. coli was purified and characterized. The molecular weight of the chitinase III from E. coli was estimated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) to be 55, 000. This agreed with the calculated molecular weight of the mature chitinase III (54, 111). However, it was different from that of the enzyme from Aeromonas sp. It showed that the chitinase III from Aeromonas sp. had an additional sugar chain, causing the higher molecular weight. Chitinase III from E. coli had almost the same enzymatic properties as chitinase III from Aeromonas sp., but the specific activity of the chitinase III from E. coli is slightly higher than that of the native chitinase III. Both enzymes hydrolyzed chitosan (80% deacetylated) well.
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  • Hiromi SANO, Shigeru MIO, Yuko KUMAGAWA, Junko KITAGAWA, Masahiro SHIN ...
    1996 Volume 60 Issue 7 Pages 1198-1200
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    We synthesized three hydantocidin derivatives and evaluated their herbicidal activity in order to elucidate the role of the spirohydantoin system at the anomeric center of hydantocidin. With application to foliage at 1000 ppm, only α-ureidoamide 14 demonstrated activity, the remaining compounds being found to be inactive.
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  • Chengcang Wu, Koichi SUZUKI, Eiichi KUWANO
    1996 Volume 60 Issue 7 Pages 1201-1203
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    The injection of an imidazole compound, KK-42, into fifth instar larvae of a silkworm (Bombyx mori, Daizo strain), which had been destined to produce diapause eggs, induced the moths to lay non-diapause eggs. The critical period for KK-42 injection in the induction of non-diapause eggs was 24 h to 72 h after the fourth ecdysis. Topical application of KK-42 to 48 h-old fifth instar larvae also induced non-diapause eggs.
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  • Katsumi SHIBATA, Hisako SHIMADA, Hiroshi TAGUCHI
    1996 Volume 60 Issue 7 Pages 1204-1206
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    We found that the catabolism of nicotinamide (Nam) differs due to an intake of Nam itself in rats. When rats were fed with a Nam-free, tryptophan-limiting diet, the major catabolite of niacin was N1-methyl-4-pyridone-3-carboxamide (4-Py). However, its percentage was changed with increasing the intake of Nam. The major metabolite was N1-methylnicotinamide (MNA) in the diet containing 0.006% Nam, or 0.1% Nam. The toxicity of excess Nam was observed when rats were fed with a 0.5% Nam-containing diet. In this diet, the major metabolite was Nam N-oxide and it was noted that the urinary excretion of nicotinic acid and its metabolite nicotinuric acid was observed. Therefore, these acids might be detected only when the toxicity of Nam appears.
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  • Takeo MIKI, Yoshiyuki TSUJIMOTO, Shinji MIYABE, Kei-ichi SUGIYAMA, Shi ...
    1996 Volume 60 Issue 7 Pages 1207-1209
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    Glutathione reductase was purified from a yeast, Hansenula mrakii IFO 0895, to approximately 3500-fold with 59% activity yield. The enzyme was homogenous on polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 56 kDa by SDS-polyacrylamide gel electrophoresis, and 123 kDa by gel filtration using a calibrated Sephadex G-150 column. The Km values for glutathione disulfide and NADPH were 21.3 μM and 14.3 μM, respectively. The enzyme was most active at pH 7.5, 55°C. The enzyme was stable up to 40°C, and between pHs 4 and 10. The enzyme was inhibited by p-chloromercuribenzoate and metal ions such as Fe3+, Cd2+, Cu2+, and Zn2+.
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  • Tsutomu KAKIMORI, Tadashi YOSHlMOTO, Hiroshi OYAMA, Naoko ODA, Yoshika ...
    1996 Volume 60 Issue 7 Pages 1210-1211
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    A chromosomal DNA fragment of Scytalidium lignicolum that encodes the mature enzyme region of acid protease B (Scytalidopepsin B), was cloned and its nucleotides sequenced. The fragment contained a 76-bp intron at the middle of the mature enzyme-coding region. The mature enzyme was composed of 206 amino acid residues with a molecular weight of 21, 550. There were some discrepancies between the amino acid sequence deduced from these results and that previously established by protein sequencing.
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  • Tadao KURATA, Noriko MIYAKE, Yuzuru OTSUKA
    1996 Volume 60 Issue 7 Pages 1212-1214
    Published: July 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    The autoxidation of L-ascorbic acid (ASA) in methanol without heavy metal ion catalysts led to the formation of dehydro-L-ascorbic acid (DASA), the main oxidation product, together with minor oxidation Products, L-threonolactone (THL) and oxalic acid (OXA), which had been reported as the major oxidation products in the reaction of ASA with singlet oxygen. The facts suggested the possible involvement of the C(2) oxygen adduct of ASA as an important intermediate compound in this autoxidation process, and it was also supported by the semi-empirical molecular orbital calculation
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