Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 60 , Issue 1
Showing 1-48 articles out of 48 articles from the selected issue
  • Akira MURAKAMI, Hajime OHIGASHI, Koichi KOSHIMIZU
    1996 Volume 60 Issue 1 Pages 1-8
    Published: January 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    Cancer chemoprevention is currently regarded as a promising avenue for cancer control. In particular, the inhibition of tumor promotion (anti-tumor promotion) in multistage carcinogenesis is expected to be an efficient strategy, because tumor promotion is experimentally accomplished through the long-term, repetitive exposures of rodents to a tumor promoter, and premalignant lesions caused by a tumor promoter regress, at least in their earlier stages. In this review, we first describe the background of cancer chemoprevention studies as well as recent results of clinical trials. Subsequently, some hypothetical biological and cellular pathways in tumor promotion are explored. In addition, the anti-tumor promoting properties of vegetables, fruits, and edible marine algae; together with their active constituents and action mechanisms thus far known, are also described. Anti-tumor promotion with food phytochemicals may be characterized as an efficient and reliable strategy for cancer chemoprevention.
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  • Soichi ARAI
    1996 Volume 60 Issue 1 Pages 9-15
    Published: January 23, 1996
    Released: February 08, 2008
    JOURNALS FREE ACCESS
    This paper pinpoints the "tertiary" function of foods which, different from the conventional "primary" and "secondary" functions that are related to nutrition and preference, respectively, is understood to be directly involved in the modulation of our physiological systems such as the immune, endocrine, nerve, circulatory, and digestive systems. Insights into this newly defined function are particularly important. in that the intake of some physiologically functional constituents of foods could be effective in preventing diseases that may be caused by disorders in these physiological systems. Technologically, it has become feasible to design and produce physiologically functional foods (simply, functional foods) that are expected to satisfy in whole or in part a today's demand for disease prevention by eating. Such public expectations are reflected in the activation and development of systematic, large-scale studies on foods as seen in "Grant-in-Aid" research sponsored by the Ministry of Education, Science, and Culture. Meanwhile, the Ministry of Health and Welfare has initiated a policy of officially approving functional foods in terms of "foods for specified health uses" as defined by new legislation. Up to now (October 1995), 58 item have thus been approved. The first was a hypoallergenic rice product approved as of June 1, 1993. Here I discuss details of studies on rice-based functional foods. Other basic and applied studies directed toward the tertiary function, with future perspectives for functional foods, are also discussed.
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  • Kanji OHYAMA
    1996 Volume 60 Issue 1 Pages 16-24
    Published: January 23, 1996
    Released: February 08, 2008
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    The complete nucleotide sequence of chloroplast DNA (121, 025 basepairs, bp) from a liverwort, Marchantia polymorpha, has made clear the entire gene organization of the chloroplast genome. Quite a few genes encoding components of photosynthesis and protein synthesis machinery have been identified by comparative computer analysis. We also identified the Complete nucleotide sequence of the liverwort mitochondrial DNA and deduced 96 possible genes in the sequence of 186, 608 bp. The complete nucleotide sequence from chloroplast DNA comprises twenty introns (19 group II and 1 group I) in 18 different genes. One of the chloroplast group II introns separated the ribosomal protein gene in the trans-position. The mitochondrial genome also has thirty-two introns (25 group II and 7 group I) in the coding regions of 17 genes. From the evolutionary point of view, we describe the origin of organellar introns which gave the evidence for their vertical and horizontal transfers and their intragenic propagation, and RNA editing which was apparently lacking in the liverwort chloroplast and mitochondrial genomes.
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  • Naoshi KAMATA, Atsushi ENOMOTO, Satoshi ISHIDA, Kozo NAKAMURA, Jun-ich ...
    1996 Volume 60 Issue 1 Pages 25-29
    Published: January 23, 1996
    Released: February 08, 2008
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    A panel of 13 monoclonal antibodies (mAbs) against distinct determinants on bovine β-lactoglobulin, a model protein antigen, were examined and compared for their ability to bind and desorb from the antigen at differing pHs and ionic strengths by an enzyme-linked immunosorbent assay and elution assay. Among them, mAb 61C1 was found to be highly sensitive to the pH, and 3 in 4 mAbs directed to the region 42-56 also strongly depended on the change in ionic strength. Because of the large proportion of charged amino acid residues in the region 42-56, the electrostatic forces are considered to be more predominant than the hydrophobic interactions in the latter antigen-antibody reactions, thereby resulting in their high sensitivity to the ionic strength.
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  • Takashi MIZUNO, Poohong YEOHLUI, Tetsuya KINOSHITA, Cun ZHUANG, Hitosh ...
    1996 Volume 60 Issue 1 Pages 30-33
    Published: January 23, 1996
    Released: February 08, 2008
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    Two chemical modification procedures, Smith degradation and formolysis processes, were used in an attempt to improve the antitumor activity of water-soluble and water-insoluble polysaccharides prepared from the fruiting body of niohshimeji, Tricholoma giganteum. The chemically modified products were examined for their antitumor effects on Sarcoma 180 solid tumor implanted in mice. The following results were as follows: Some Smith degradation products, i.e., O-R-Flo-c-βP and O-R-FA-2 prepared from water-soluble polysaccharides, and O-R-FII-1 and O-R-FIII-2-c from water-insoluble polysaccharides, had higher antitumor activities than the original polysaccharides. None of the formolysis products, F-Flo-a, F-W-Flo-a, F-FA-3, F-W-FA-3 from water-soluble polysaccharides, and F-FII-2, F-W-FII-2, F-FIII-2-b, and F-W-FIII-2-b prepared from water-insoluble polysaccharides had improved antitumor activities.
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  • Yoshihiro KATO, Naoto OHNISHI, Shigeru TAKAHASHI, Zheng-Yu WANG, Tsune ...
    1996 Volume 60 Issue 1 Pages 34-38
    Published: January 23, 1996
    Released: February 08, 2008
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    Our screening system using Arabidopsis thaliana, enabled us to evaluate the effect of 38 known growth regulators on plant growth promotion. Eleven compounds in the study were found to show a promoting effect upon Arabidopsis dry weight and leaf number; in particular, oligosaccharides (OS) such as raffinose and stachyose had a marked effect. Detailed experiments indicated that the effect of OS on plant growth was not merely derived from its potential carbon source. Among the monosaccharides comprising stachyose, galactose showed the best promoting effect on plant growth.
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  • Junichi MATSUMOTO, Masako HIGUCHI, Mamoru SHIMADA, Yoshikazu YAMAMOTO, ...
    1996 Volume 60 Issue 1 Pages 39-43
    Published: January 23, 1996
    Released: February 08, 2008
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    To discover the molecular properties of two distinct NADH oxidases, corresponding to H2O2-forming oxidase (NOX-1) and H2O-forming oxidase (NOX-2) induced in Streptococcus mutans, for the first step we had cloned and sequenced the nox-1 gene encoding NOX-1. In this paper, a nox-2 gene encoding NOX-2 from S. mutans was cloned, and the nucleotides sequenced. The nox-2 gene comprises 1371 base-pairs, encoding a polypeptide of 457 amino acid residues. The deduced relative molecular mass (AL = 49919)agreed with the previous value obtained from the purified NOX-2 protein. The nox-2 gene was expressed in Escherichia coli using its own promoter. Alignment of the NOX-2 protein sequence with that of the NOX-1 showed that the proteins do not significantly resemble each other. Comparisons with the NADH oxidase from Streptococcus faecalis 10C1 yield identities of 41%. The redox-active cysteine in the enzyme from S.faecalis was found to correspond to Cys 44 in the NOX-2.
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  • I Gede Putu WIRAWAN WIRAWAN, Mineo KOJIMA
    1996 Volume 60 Issue 1 Pages 44-49
    Published: January 23, 1996
    Released: February 08, 2008
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    It has been proposed that during tumorigenesis of plants by Agrobacterium tumefaciens, the T-strand is transferred into the host plant cell in the form of a complex consisting of VirD2 and VirE2 proteins. In this paper, we present data supporting the hypothesis that another protein, AcvB (a gene product of a chromosomal virulence gene, acvB-), also binds to the T-strand in the periplasm to mediate its transfer into the plant cell. An avirulent mutant strain (B119 strain, acvB-) of A. tumefaciens was shown to be impaired in the transfer of T-strands into the cytoplasm of host plant cell by an experiment using a binary Ti plasmid containing aβ-glucuronidase (GUS) reporter gene with an intron. The immunoprecipitation experiment demonstrated the in vitro formation of a complex of single stranded (ss)T-DNA and AcvB. In the periplasm of A. tumefaciens (A208 strain, virulent, acvB+) induced with acetosyringone, the T-strand complex containing AcvB and VirE2 proteins was detected immunochemically, while such a complex was not detected with B119 strain. When complexed with AcvB, ssDNA was incorporated into tomato leaf protoplasts with 4.5 times higher efficiency than ssDNA alone. Thus, AcvB protein seems to mediate the transfer of T-complex into the cytoplasm of host plant cell by forming a complex with T-strand DNA.
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  • I Gede Putu WIRAWAN, Mineo KOJIMA
    1996 Volume 60 Issue 1 Pages 50-53
    Published: January 23, 1996
    Released: February 08, 2008
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    The chromosomal virulence gene (acvB) that was originally isolated from Agrobacterium tumefaciens harboring a nopaline type Ti plasmid pTiT37 (A208 strain) was detected in all Agrobacterium strains tested. In Agrobacterium tumefaciens strains harboring an octopine type Ti plasmid, the acvB gene was detected on both Ti plasmid and chromosomal DNA. The acvB gene homolog on an octopine type Ti plasmid was also shown to be functional by a gene disruption experiment. All bacteria strains that Contained the acvB gene expressed the gene, and the gene product (AcvB protein) was localized in the periplasm. On the other hand, acvB gene was not detected in Rhizobium phaseoli, Rhizobium meliloti, Pseudomonas fluorescens, or Bacillus subtilis. Such distribution of acvB gene among various bacteria supported our previous proposal that the acvB gene is involved in the transfer of T-DNA into plants.
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  • Izumi SASAKI, Hideo NAGAYAMA
    1996 Volume 60 Issue 1 Pages 54-56
    Published: January 23, 1996
    Released: February 08, 2008
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    A novelβ-glucosidase of Botrytis cinerea, shown to be very inducible in the lesions, was examined with respect to its pathogenicity. By activity staining, the occurrence ofβ-glucosidase activity was noted at the surface and middle lamella of tissues in the lesions. When the purifiedβ-glucosidase was reacted with apple fruit tissues, polysaccharides were released, endogenous K+ ions of the plant leaked out, and the tissues were macerated. Thus, it was suggested that the enzyme can degrade the apple fruit tissues by itself.
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  • Ayako YOSHIDA, Yutaka TAKAGAKI, Takahiro NISHIMUNE
    1996 Volume 60 Issue 1 Pages 57-60
    Published: January 23, 1996
    Released: February 08, 2008
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    An enzyme immunoassay (EIA) for phycocyanin in foods was developed. Anti-phycocyanin monoclonal antibodies were obtained from A/J mice immunized with phycocyanin. The phycocyanin in a food was extracted by dissolving the sample in a borate buffer solution, pH 8.0 (BBS) and adjusting the pH value of this solution to 8.0 with NaOH. The extract was then diluted more than 10 fold with 1% gelatin in BBS. Phycocyanin was determined by avidin-biotin sandwich EIA, using the P26-8 monoclonal antibody as the solid-phase antibody and the P277-4 monoclonal antibody as the enzyme-labeled antibody. The working range for a quantitative analysis was 100-1000 ng/ml, and the detection limit was 10μg/g of the original sample. Recoveries of phycocyanin from foods by this assay were > 71% for candy, and > 66% for ice cream and sherbet. Phycocyanin was assayed in 22 blue;, green-, purple-, and brown-colored commercial foods; and detected in one green colored-jelly at 49μg/g.
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  • Shoji HATANO, Motoharu UDOU, Nobuyoshi KOGA, Ken-ichi HONJOH, Takahisa ...
    1996 Volume 60 Issue 1 Pages 61-64
    Published: January 23, 1996
    Released: February 08, 2008
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    After frozen storage for 7 d, the viability and CO2 productivity of a conventional baker's yeast strain D greatly decreased. The viability of a freeze-tolerant strain, DFT, used for the frozen dough method slightly decreased after the same storage period, while the CO2 productivity greatly decreased. The CO2 productivity and DNase I inhibitory activity of actin of the cell-free extracts prepared immediately after thawing from 7-d frozen-stored cells markedly decreased in both strains. In DFT; however, the productivity and the inhibitory activity of the cell-free extract increased when the extract was prepared after incubation of the frozen-thawed cells at 30°C. The increase in the inhibitory activity first occurred and then the increase in the CO2 productivity. Gel filtration patterns of actin and glycolytic enzymes were compared between cell-free extracts of both strains. Peaks of actin and activity peaks of hexokinase and pyruvate kinase decreased in the strain D after frozen storage, but only slightly in the strain DFT. After frozen storage, phosphofructokinase activity peak Shifted to a lower molecular weight in strain D.
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  • Yumiko IWAHASHI, Hideo KOIZUMI, Hiroshi HOSODA
    1996 Volume 60 Issue 1 Pages 65-68
    Published: January 23, 1996
    Released: February 08, 2008
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    The effects of compounds that influenced the redox condition on the senescence of detached Brassica campestris leaves were examined. Glutathione treatment promoted the senescence of detached Brassica leaves in the dark. Glutathione treatment also increased the rate of respiration and serine content in the dark. The buthionine sulfoxisamine (a potent and specific inhibitor ofγ-glutamylcystein synthetase (EC 6.3.2.2)) strongly suppressed leaf senescence. These findings suggest that the intracellular glutathione concentration may be involved in importance for leaf senescence.
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  • Syed Mohammed SHOEB, Eiichi SHIMIZU, Takamitsu YORIFUJI
    1996 Volume 60 Issue 1 Pages 69-72
    Published: January 23, 1996
    Released: February 08, 2008
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    An enzymatic method for the differential measurement of 1, 4-diguanidinobutane (DGB), agmatine, and putrescine was developed. DGB and agmatine were converted to N-carbamoylagmatine and N-carbamoylputrescine respectively, with agmatine deiminase from Rhodococcus sp. C-x. The initial concentration of DGB was determined from the final concentrations of the guanidino groups of N-carbamoylagmatine. The sum of the initial concentrations of DGB and agmatine was determined from the final concentration of the ureido groups. The concentration of putrescine was measured with putrescine oxidase from Micrococcus rubens IFO 3768; which had no activity toward agmatine. Three of the four commercial preparations of agmatine sulfate tested were found to contain 21-32% (w/w) of DGB and putrescine.
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  • Hiroki SHIMIZU, Yukishige ITO, Yuji MATSUZAKI, Hiroyuki IIJIMA, Tomoya ...
    1996 Volume 60 Issue 1 Pages 73-76
    Published: January 23, 1996
    Released: February 08, 2008
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    Phthaloyl (Phth) is a valuable amino-protecting group for use in synthetic carbohydrate chemistry. Its strong 1, 2-trans-directing nature in a glycosylation reaction, when it is introduced to the C__--2 position of a glycosyl donor, makes the construction ofβ-GlcNAc or β-GalNAc glycosides quite straightforward. The Phth group can be removed by using an appropriate nucleophile, most typically hydrazine; however, this transformation often requires a long reaction time at elevated temperature when applied to a large oligosaccharide. We studied the 4, 5-dichlorophthaloyl (DCPhth) group as an alternative to Phth. A thioglycoside carrying a DCPhth group at the C__--2 position was reacted with alcohol by the action of PhSeNPhth-TMSOTf to selectively give the correspondingβ-glycoside. DCPhth Could then be .removed under mild conditions by using ethylenediamine or hydrazine/MeOH at room temperature.
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  • Shou TAKASHIMA, Akira NAKAMURA, Haruhiko MASAKI, Takeshi UOZUMI
    1996 Volume 60 Issue 1 Pages 77-82
    Published: January 23, 1996
    Released: February 08, 2008
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    Sixβ-glucosidases, two endoglucanases, and an exoglucanase were purified from the culture extract of a thermophilic fungus Humicola grisea var. thermoidea IFO9854. The molecular weights of the purified enzymes estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ware from 38, 500 to 115, 000 and some of the β-glucosidase consisted of several polypeptides. The optimal pHs of these enzymes were between 5.0 to 7.0 and the optimal temperatures were between 50 to 70°C. The β-glucosidases had various substrate specificities with cellooligosaccharides and several p-nitrophenyl (PNP)-β-D-saccharides and showed different kinetic parameters for p-nitrophenyl-β-D-glucoside (PNPG). Probably synergistic action between the cellulases of H. grisea, including the enzymes purified in this study, is needed for the efficient degradation of cellulose.
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  • Shinobu ODA, Akio KATO, Naotoshi MATSUDOMI, Hiromichi OHTA
    1996 Volume 60 Issue 1 Pages 83-87
    Published: January 23, 1996
    Released: February 08, 2008
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    Microbial oxidation of racemic citronellol was done on the interface between a nutrient agar plate and decane (interface bioreactor). While Rhodococcus accumulated (R)-Citronellal (21-80% e.e.), many yeasts accumulated (S)-citronellic acid (20-68% e.e.) as the oxidation product. For the production of (R)-citronellal and (S)-citronellic acid, Rhodococcus equi IFO 3730 and Hansenula anomala IFO 0147 were the best strains, respectively. While citronellol-oxidation in R. equi IFO 3730 was (S)-selective, citronellal-oxidation was (R)-selective. Although H anomala had also both (S)-selective alcohol and aldehyde dehydrogenases (constitutive, NAD+ -dependent), the equilibrium of the alcohol dehydrogenase Shifted to. reduction Of citronellal. Geotrichum candidum JCM 01747 accumulated very high concentrations of citronellic acid (conversion yield 90% in 5 days or accumulation 65 mg/ml in 13 days) in spite of the strong toxicity of the acid, although the optical purity was low. For the alleviation of the toxicity of citronellol and accumulation of toxic citronellic acid, the interface bioreactor is superior to the organic-aqueous two-liquid-phase system (dispersion system).
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  • Hideyuki YASUDA, Katsumasa SHIMIZU, Kenji OSAWA
    1996 Volume 60 Issue 1 Pages 88-91
    Published: January 23, 1996
    Released: February 08, 2008
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    Fourteen diterpenes containing one novel compound from the leaves of Rabdosia trichocarpa had significant deodorizing activity against methanethiol (CH3SH), the main source of halitosis. The compounds generated from the reaction between oridonin, the main compound of the 14 diterpenes and CH3SH were isolated and determined to be two adducts, 17α-CH3S-oridonin and 17β-CH3S-oridonin. This implies that CH3SH reacted with oridonin, which had an exocyclic methylene group conjugated with a ketone, by 1, 4-addition. Oridonin reduced the bad odor by converting CH3SH to these non-volatile compounds. Oridonin showed significant deodorizing effect in the basic pH range, and had almost no effect in the acidic pH range. The rate of the deodorizing action of oridonin was relatively fastar than that of tea Catechins, which are widely used as oral deodorizers. The deodorizing effect of several α, β-unsaturated carbonyl compounds against CH3SH was also determined.
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  • Kohji YAMAGUCHI, Tomoko TSUJI, Daisuke UEMURA, Kiyosi KONDO
    1996 Volume 60 Issue 1 Pages 92-94
    Published: January 23, 1996
    Released: February 08, 2008
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    Nerve growth factor (NGF) inducers, for example, 4-methylcatechol, pyrroloquinoline quinone, kansuinin A, and ingenol triacetate, stimulate NGF synthesis in L-M cells, but the mechanism of NGF induction by NGF inducers is not known. Using the four different types of previously described NGF inducers, we proved induction of cyclooxygenase activity by NGF inducers and detected prostaglandins D2 and E2 as metabolites of arachidonic acid. From the observation that the induction of NGF by each NGF inducers was inhibited by cyclooxygenase inhibitors or dexamethasone, cyclooxygenase activation is supposed to be an essential process for NGF induction.
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  • Hiroyuki MIYA, Mitsuru KAWADA, Yoshio SUGIYAMA
    1996 Volume 60 Issue 1 Pages 95-98
    Published: January 23, 1996
    Released: February 08, 2008
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    More than 450 bacterial strains were examined for their ability to reduce ethyl 2-methyl-3-oxobutanoate (1) to ethyl 3-hydroxy-2-methylbutanoate: Nine strains of enteric bacteria were found to predominantly yield the product with a syn configuration. Of these strains, five gave ethyl (2R, 3S) 3-hydroxy-2-methylbutanoate (2a) with more than 98% diastereoisomeric excess (d.e.) and over 99% enantiomeric excess (e.e.) Klebsiella pneumoniae IFO 3319 was found to give the highest d.e., e.e., and chemical yield at a high concentration of 1. Reduction of 1 was than done with the bacterium in a 200-liter fermentor. Two kilograms of 1 was converted to 2a with 99% d.e., , >99% e.e., and 99% chemical yield.
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  • Mei-Hwei LEE, Richie L.C. CHEN, Kiyoshi MATSUMOTO
    1996 Volume 60 Issue 1 Pages 99-102
    Published: January 23, 1996
    Released: February 08, 2008
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    An automated multi-channel continuous-flow analyzing system was constructed for the rapid measurement of both the total amino acid content and the L-glutamate content of green tea infusions. L-Glutamate in samples was oxidized and deaminated enzymatically in a channel with a mini-reactor that was packed with L-glutamate oxidase immobilized on glass beads, and the evolved ammonium ions were measured by a fluorogenic reaction withο-phthalaldehyde andβ-mercaptoethanol. The total amino acid content was measured in a channel with another mini-reactor which was tilled with immobilized L-amino acid oxidase. The fluorometric method is not subject to interference by reducing substances such as tea catechins and ascorbate, and the analytes in tea infusions were measured without pretreatment of samples. The use of this system for evaluation of tea quality was investigated.
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  • Uichi NISHIYAMA, Makoto UBUKATA, Junji MAGAE, Takao KATAOKA, Ferenc ER ...
    1996 Volume 60 Issue 1 Pages 103-107
    Published: January 23, 1996
    Released: February 08, 2008
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    Tautomycin, a protein serine/threonine phosphatase inhibitor, was chemically degraded, and five derivatives were investigated for their biological activities. None of them exerted any inhibitory effects on the activity of protein phosphatase types 1 and 2A. However, one derivative, named TM2a, induced a significant morphological change (bleb-formation) of human myeloid leukemia K562 cells. TM2b, the trimethyl ester of TM2, did not induce bleb-formation. Thus, the maleic anhydride structure played an important role in the biological activity. The biological properties of TM2a toward K562 cells resembled those of a phorbol ester, rather than of tautomycin. The phorbol ester-induced bleb formation was abrogated by a non-specific inhibitor of protein kinases, staurosporine, and by an inhibitor of protein kinase C (PKC), H-7, but TM2a-induced bleb formation was abrogated only by staurosporine. Enhanced phosphorylation of the two proteins was observed after their exposure to TM2a. This Suggest that the effect was not due to any inhibition of protein phosphatase 1 or 2A, but rather to the activation of an unidentified kinase, possibly of the PKC family, or to inhibition of a protein phosphatase other than type 1 or 2A.
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  • Hiroshi KAWASHIMA, Kengo AKIMOTO, Saeree JAREONKITMONGKOL, Norifumi SH ...
    1996 Volume 60 Issue 1 Pages 108-110
    Published: January 23, 1996
    Released: February 08, 2008
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    Curcumin (1, 7-bis(4-hydroxy-3-methoxyphenyl)-1, 6-heptadiene-3, 5-dione) inhibited noncompetitively rat liver microsomal Δ5 desaturase (Ki=36μM) and Δ6 desaturase (Ki=28μM). Although curcumin has a symmetrical structure with a methylene group as the center, only half the structure is essential foe the desaturase inhibition. The structure necessary for the inhibition is similar to that of alkyl gallate (H. Kawashima et al., Biochem. Biophys. Acta, in press), i.e., a 3-hydroxy group of the aromatic ring is essential for the inhibition and a free carboxyl group at the end opposite to the aromatic ring interferes with the inhibitory effect. The following structural features of curcumin are necessary for the desaturase inhibition: (i) the aromatic ring conjugated with the double bond between the 1 and 2 (or 6 and 7) positions; (ii) both 4-hydroxy and 3-methoxy groups (for both desaturase inhibitions); and (iii) only a 4-hydroxy group (for Δ6 desaturase inhibition).
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  • Soumitra Kumar SAHA, Satomi NISHIJIMA, Hiroshi MATSUZAKI, Isao SHIBUYA ...
    1996 Volume 60 Issue 1 Pages 111-116
    Published: January 23, 1996
    Released: February 08, 2008
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    The mechanism that assures the balanced synthesis of zwitterionic (phosphatidylethanolamine) and acidic phospholipids (phosphatidylglycerol and cardiolipin) in Escherichia coli has been examined by genetically manipulating the two enzymes at the biosynthetic branch point, i.e., phosphatidylglycerophosphate synthase, encoded by pgsA, and phosphatidylserine synthase, encoded by pssA. A mutant in which the most part of the pssA gene was replaced with a drug resistance gene lacked phosphatidylserine synthase and phosphatidylethanolamine and required divalent metal ions for growth, as did a previously reported insertion-inactivated pssA mutant. When this mutant harbored a plasmid containing a Bacillus subtilis gene that encodes membrane-bound phosphatidylserine synthase, the phosphatidylethanolamine content was dependent on its activity, in contrast to that with the soluble E. coli counterpart. A defective mutation, pgsA3, caused reductions not only in acidic-phospholipid synthesis but also in phosphatidylethanolamine synthesis, despite the normal level of phosphatidylserine synthase activity. These results, together with previous observations, indicate that phosphatidylserine synthesis requires the membrane-associated form of phosphatidylserine synthase, which is related to the membrane-levels of acidic phospholipids, thus yielding balanced compositions of zwitterionic and acidic phospholipids.
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  • Hiroe YOSHIOKA, Goro AKAI, Kouichi YOSHINAGA, Kunihiko HASEGAWA, Hisas ...
    1996 Volume 60 Issue 1 Pages 117-119
    Published: January 23, 1996
    Released: February 08, 2008
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    Gamma ray-induced scission of puC18 plasmid DNA prepared from E. coli was examined in the presence of a green tea percolate and its main constituents, L-ascorbic acid (used as the sodium salt) and (-)-epigallocatechin gallate. Each of these showed a protecting effect against DNA scission. The relationship between the protecting effect against DNA scission and the scavenging effect of the hydroxyl radical was examined, and is discussed from the viewpoint of interaction with DNA.
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  • Tomonari WADA, Yasuo HAYASHI, Hisao SHIBATA
    1996 Volume 60 Issue 1 Pages 120-121
    Published: January 23, 1996
    Released: February 08, 2008
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    Two novel prenylated phenolics were isolated from Boletinus asiaticus anid B. paluster fungi. Their structures were determined by spectroscopic and chemical methods.
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  • Iori MAEDA, Yasuyuki SHIMOHIGASHI, Hiroshi KIHARA, Motonori OHNO
    1996 Volume 60 Issue 1 Pages 122-124
    Published: January 23, 1996
    Released: February 08, 2008
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    A cellulase with activity as a cellobiohydrolase [EC 3.2.1.91] was purified from the intestinal juice of the giant snail Achatina fulica.The enzyme (Mr = about 23, 000, and pl= about 5.3) also had a weak β-glucosidase activity. The amino acid sequence of the N-terminal 20 amino acids was analyzed, and no similarity was noted for sequences of other known cellobiohydrolases.
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  • SHIMADA Kazuko, OKADA Hiromi, MATSUO Kayoko, YOSHIOKA Sawako
    1996 Volume 60 Issue 1 Pages 125-127
    Published: January 23, 1996
    Released: February 08, 2008
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    The antioxidative effects of xanthan and other polysaccharides were evaluated by measuring the Fe2+-induced consumption of oxygen dissolved in the oil/water emulsion. The degree of oxygen consumption was, from the lowest, in the order of xanthan <pec-tin <guar gum &le; tragacanth gum, and was closely related to the Fe2+-binding ability of the polysaccharides. The oxygen consumption was also affected by the viscosity of the aqueous solution in the emulsion, but not by the oil-droplet size. The antioxidative mechanism for xanthan can be accounted for primarily by its high metal-binding ability, and additionally by its viscous behavior.
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  • Masayuki FUJITA, Yasuhiko ADACHI
    1996 Volume 60 Issue 1 Pages 128-130
    Published: January 23, 1996
    Released: February 08, 2008
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    The effects of various plant hormones on the accumulation of glutathione S-transferase (EC 2.5.1.18) in pumpkin suspension cells were examinied. 2, 4-Dichlorophenoxyacetic acid most effectively elevated the level of glutathione S-transferase among the tested plant hormones, although induction of the enzyme seemed not to be related to the auxin reaction. The chemical structures of the 2, 4-dichlorophenoxyacetic acid derivatives required to induce glutathione S-transferase are discussed.
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  • Masahiko NONAKA, Yukihiro MATSUURA, Masao MOTOKI
    1996 Volume 60 Issue 1 Pages 131-133
    Published: January 23, 1996
    Released: February 08, 2008
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    Ca2+-independent microbial transglutaminase of a variant of Streptoverticillium mobaraense was compared with Ca2+-dependent guinea pig liver transglutaminase as a tool for incorporating lysine or lysine dipeptides into a food protein. The microbial enzyme was able to incorporate up to ca. 12 mol lrsine into a mole of citra-conylated αs1-casein. Twenty two lysine dipeptides could be the substrate for incorporation catalyzed by the enzyme. The microbial enzyme showed much higher incorporation of lysine or lysine dipeptides than the guinea pig liver enzyme, which was attributed to the higher themostability of the microbial enzyme.
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  • Masaaki ONDA, Mayumi HAYASHI, Masahito SUIKO, Ming-Cheh LIU, Hiroshi N ...
    1996 Volume 60 Issue 1 Pages 134-136
    Published: January 23, 1996
    Released: February 08, 2008
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    Adenosine 5'-phosphosulfate (APS) kinase from a thermophilic bacterium, Bacillus stearothermophilus, was purified to apparent homogeneity. The apparent molecular weight was 50 kDa, consisting of two 26-kDa subunits. The enzyme was very thermostable and lacked cysteine and methionine residues. Enzyme activity was more stimulated with Mn2+, Zn2+, or Co2+ than with Mg2+ and the Km for ATP and APS were 220 μM and 42 μM, respectively.
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  • Masahito SUIKO, Tamaki TOJO, P.H.Prasantha FERNANDO, Yoichi SAKAKIBARA ...
    1996 Volume 60 Issue 1 Pages 137-138
    Published: January 23, 1996
    Released: February 08, 2008
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    Three mammalian and eight non-mammalian arylsulfatases were inivestigated for their activities toward tyrosine-0-sulfate (TyrS) in peptides. None of the mammalian arylsulfatases exhibited detectable activities toward TyrS-containing peptides. Of the non-mammalian arylsulfatases tested, Types VII, VIII, and H-1, 2, and 5 displayed strong activity on endo-TyrS residues. The prokaryotic sulfatase, Type VI, was active only on free TyrS and N-terminal TyrS of Leu-enkephalin. All the sulfatases were active on p-nitrophenyl sulfate and p-nitrocatechol sulfate.
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  • Masakatsu SUZUKI, Tadao SAITO, Takatoshi ITOH
    1996 Volume 60 Issue 1 Pages 139-141
    Published: January 23, 1996
    Released: February 08, 2008
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    6-Phospho-β-galactosidase from Lactobacillus gasseri JCM 1031 was purified from lactobacilli to homogeneity, about 118-fold, with 0.5% recovery by several chromatographies. The molecular mass and isoelectric point of the purified enzyme were 58 kDa and pI 5.5, respectively. The Km and Vmax for o-nitrophenyl-β-D-ga-lactopyranoside-6-phosphate were 0.8 mM and 116.4 μmol/min/mg, respectively. Reducing agent, Fe2+ ion, and EDTA activated but PCMB, Zn2+, and Hg2+ ions strongly inhibited the enzymatic activity.
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  • Shunji TAKAHASHI, Tomoo SAKATA, Goro TAMURA
    1996 Volume 60 Issue 1 Pages 142-144
    Published: January 23, 1996
    Released: February 08, 2008
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  • Yasuhide OTA, Yutaka ITABASHI, Masaki HASUO
    1996 Volume 60 Issue 1 Pages 145-146
    Published: January 23, 1996
    Released: February 08, 2008
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    The positional specificity index (PSI) of microbial lipases was measured using chiral phase high-pressure liquid chromatography (HPLC). The PSI value calculated was more precise than that using thin-layer chromatography, especially when the PSI was near 100.
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  • Yoshiko MINAMI, Takeo KANAFUJI, Kazuo MIURA
    1996 Volume 60 Issue 1 Pages 147-149
    Published: January 23, 1996
    Released: February 08, 2008
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    An enzyme, β-glucosidase, which hydrolyzes indican (indoxyl-β-D-glucoside) was isolated in pure form from a plant, Polygonum tinctorium, and characterized. The enzyme showed specifically a low Km for indican (0.34mM). The enzyme reacted with some other β-glucosides having aromatic groups but not with α-glucoside or other glycosides like galactoside. The activity was inhibited by several metal cations such as Cu2+ and by typical inhibitors for β-glucosidase such as D-glucono-1, 5-lactone although these inhibitors required high concentrations.
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  • Yasuyoshi SAKAI, Nobuyuki YOSHIDA, Yoshiki TANI, Nobuo KATO
    1996 Volume 60 Issue 1 Pages 150-151
    Published: January 23, 1996
    Released: February 08, 2008
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    In Fusarium oxysporum S-1F4, fructosyl lysine oxidase (FLOD) was induced with Nε-fructosyl Nα-Z-lysine (ε-FL), which is a model compound of a glycated protein, and the induction was inhibited by the addition of cycloheximide in the growing cells. FLOD formation was greatly enhanced in an autoclave-browned medium containing glucose and L-lysine. Some Amadori compounds formed from glucose and L-lysine during autoclaving were assumed to induce the enzyme.After optimization of the culture conditions, FLOD produced in the browned medium was comparable to that in the medium with ε-FL.
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  • Atsushi SATOH, Yuji NARITA, Natsuyo ENDO, Hiroyuki NISHIMURA
    1996 Volume 60 Issue 1 Pages 152-153
    Published: January 23, 1996
    Released: February 08, 2008
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    A potent allelochemical in Glehnia littoralis F. Schm. was investigated. Falcalindiol was isolated from G. littoralis; 859.9 mg/kg of fresh root and 62.5 mg/kg of fresh aerial parts. Its structure was elucidated by spectroscopic methods, and the antimicrobial activities of falcalindiol were evaluated by the paper disk method against several microorganisms. The plant growth inhibition of falcalindiol wad also investigated.
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  • Minoru SATO, Toshiki NAKANO, Masaaki TAKEUCHI, Nobuhiro KANNO, Eizou N ...
    1996 Volume 60 Issue 1 Pages 154-156
    Published: January 23, 1996
    Released: February 08, 2008
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    The effects of dietary octopine, which is one of the major extractive component of marine molluscs, on the level of serum and liver cholesterol of rats fed with cholesterol-enriched or cholesterol-free diets were investigated. Dietary supplementation with 1.5% octopine in a cholesterol-enriched diet significantly decreased the serum total- and VLDL + LDL-cholesterol levels and by contrary increased the serum HDL-cholesterol level in rats. The same tendency was observed in the rats fed with 1.5% octopine in a cholesterol-free diet.
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  • Mitsunori KIRIHATA, Tsuguhiro MORIMOTO, Itsuo ICHIMOTO, Mitsue KOBAYAS ...
    1996 Volume 60 Issue 1 Pages 157-158
    Published: January 23, 1996
    Released: February 08, 2008
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    The synthesis of O-[(o-carboran-1-yl)methyl]-3-hydroxytyrosine (CMHT), a novel o-carborane-containinig amino acid for boron neutron capture therapy, was achieved by the short-step sequence, in which the aldol-type condensation of 4-[(o-carboran-1-yl)-methoxy]benzaldehyde (1) with ethyl isocyanoacetate (2) gave a trans/cis mixture of the oxazolines 5a dnd 5b in a 9:1 ratio. Separated trans-oxazoline 5a was transformed into Syn-CMHT in a moderate yield.
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  • Masatomo KOBAYASHI, Kyoko YOSHIZAWA, Akira SAKURAI, Teruko NAKAMURA
    1996 Volume 60 Issue 1 Pages 159-160
    Published: January 23, 1996
    Released: February 08, 2008
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    Gibberellin A1 (GA1), GA15, GA19, GA20, GA29, GA44, and abscisic acid (ABA) were identified from vegetative shoots of Japanese cherry (Prunus spachiana Kitamura f. ascendens Kitamura, Edo-higan) by full-scan GC-MS. GA4, GA9, GA34, and GA53 were also tentatively identified. The endogenous levels of these gibberellins and of ABA were higher in the weeping cherry (P.spachiana Kitamura f. spachiana cv. Plenorosea, Yaebeni-shidare) than in the normal cultivar (Edo-higan).
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  • Masayuki MACHIDA, Trini Violeta Jime'nez GONZALEZ, Lim Kong BOON, Kats ...
    1996 Volume 60 Issue 1 Pages 161-163
    Published: January 23, 1996
    Released: February 08, 2008
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    We have isolated an enolase gene (enoA) from Aspergillus oryzae by heterologous hybridizationi using the corresponding Saccharomyces cerevisiae ENO2 gene as a probe. A 2.9-kb BglII; fragment contained the entire structural gene enoA including 5'-and 3'-flanking regions. The homology between A. oryzae enoA and S.cerevisiae ENO2 genes is 66.9% when introns are removed. Genomic Southern analysis indicated that there is only one enolase gene in A.oryzae.
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  • Hiroshi TAGUCHI, Nobuko OHSHIMA, Katsumi SHIBATA
    1996 Volume 60 Issue 1 Pages 164-165
    Published: January 23, 1996
    Released: February 08, 2008
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    Relative activities of pyridine nucleotides themselves to nicotinic acid as niacin nutriture were investigated using Lactobacillus plantarum ATCC 8014. This organism is generally used as a test organism for measuring the niacin contents in foods, because this organism lacks the de novo NAD biosynthetic pathway, therefore, nicotinic acid or nicotinamide is required for growth. Nicotinic acid mononucleotide and nicotinic acid adenine dinucleotide had little niacin activity, while nicotinamide mononucleotide, NAD+, and NADP+ had a little niacin activity and the relative activity of the respective compound to nicotinic acid as niacin nutriture was 1/14, 1/5, and 1/33.
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  • Chiaki KATO, Maria SMORAWINSKA, Takako SATO, Koki HORIKOSHI
    1996 Volume 60 Issue 1 Pages 166-168
    Published: January 23, 1996
    Released: February 08, 2008
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    A pressure-regulated operon was cloned and sequenced from a barophilic bacterium strain DB6705. Gene expression by this promoter was regulated at the level of transcription by elevated pressure in the barophilic strain. The promoter sequence was similar to the promoter of ompH from Photobacterium sp. strain SS9.
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  • Kazutoshi SAYAMA, Kayoko OZEKI, Masako TAGUCHI, Itaro OGUNI
    1996 Volume 60 Issue 1 Pages 169-170
    Published: January 23, 1996
    Released: February 08, 2008
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    To find whether green tea and tea catechins have effects on the development of mammary glands, virgin DDD mice were fed on diets containing green tea and tea catechins. The degree of mammary gland development was examined by duct-alveolar growth and DNA content. The results indicated that green tea, but not tea catechins, has a growth-promoting effect on mammary gland development.
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  • Mitsuharu TANAKA, Junya MIZUTANI, Satoshi TAHARA
    1996 Volume 60 Issue 1 Pages 171-172
    Published: January 23, 1996
    Released: February 08, 2008
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    A cel1-free system of Botrytis cinerea, which can metabolize prenylated isoflavones into the corresponding dihydropyrano- and dihydrofurano-isoflavones, revealed the transformation to be initially catalyzed by a microsomal monooxygenase to yield an epoxy intermediate. The enzyme activity was markedly enhanced by pretreating the mycelia with 6-prenylnaringenin, and was dependent on NADPH and O2.
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  • Shou TAKASHIMA, Akira NAKAMURA, Hiroshi IIKURA, Haruhiko MASAKI, Takes ...
    1996 Volume 60 Issue 1 Pages 173-176
    Published: January 23, 1996
    Released: February 08, 2008
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    We report the cloning and sequencing of a Trichoderma reesei genomic DNA clone that encodes a protein similar to the Aspergillus CREA, a carbon catabolite repressor. The deduced amino acid sequence predicts a zinc finger protein of 402 amino acids in length. The overall amino acid sequence of the T. reesei CREA shows about 52% similarity with Aspergillus CREAs.
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  • Toshihiko SUGANUMA, Norihito TAHARA, Kanefumi KITAHARA, Tomonori NAGAH ...
    1996 Volume 60 Issue 1 Pages 177-179
    Published: January 23, 1996
    Released: February 08, 2008
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    An acid-stable α-amylase (AA) was purified from an acidic extract of citric acid-koji (A. usamii var.). The N-terminal sequence of the first 20 amino acids of the enzyme was identical with that of AA from A. niger, but the two enzymes differed in molecular weight. HPLC analysis for identifying the anomers of products indicated that the AA hydrolyzed maltopentaose (G5) at the third glycoside bond predominantly, which differed from Taka-amylase A and the neutral α-amylase (NA) from the citric acid-koji.
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