Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 63 , Issue 11
Showing 1-38 articles out of 38 articles from the selected issue
Analytical Chemistry Note
Organic Chemistry Regular Papers
  • Yoshihito SHIONO, Kohki AKIYAMA, Hideo HAYASHI
    1999 Volume 63 Issue 11 Pages 1910-1920
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Four new okaramine congeners, okaramines J, K, L and M, were isolated from okara fermented with Penicillium simplicissimum ATCC 90288, together with five biogenetically related compounds, cyclo (8a-(α,α-dimethylallyl)-L-Trp-8a-(α,α-dimethylallyl)-L-Trp), cyclo (N8-(α,α-dimethylallyl)-L-Trp-6a′-(α,α-dimethylallyl)-L-Trp), cyclo (L-Trp-L-Trp), cyclo (6a′-(α,α-dimethylallyl)-L-Trp-L-Trp), and cyclo (N8-(α,α-dimethylallyl)-L-Trp-L-Trp). Their structures were elucidated on the basis of spectroscopic methods. The new okaramines exhibited no insecticidal activity against silkworms.
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  • Hiroaki TOSHIMA, Masatoshi SAITO, Teruhiko YOSHIHARA
    1999 Volume 63 Issue 11 Pages 1934-1941
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      All four stereoisomers of (2S, 3R)-(+)-piscidic acid were synthesized with high optical purity via Sharpless catalytic asymmetric dihydroxylation of (Z)- and (E)-trisubstituted olefins in 6 steps from (4-hydroxyphenyl)pyruvic acid. The Wittig reaction of methyl (4-hydroxyphenyl)pyruvate with (carbomethoxymethylene)triphenylphosphorane gave (Z)- and (E)-trisubstituted olefins in a 3:1 ratio. After protecting the phenolic hydroxyl group as the tert-butyldimethylsilyl ether, the (Z)-olefin was subjected to asymmetric dihydroxylation by using the chiral ligand, dihydroquinidine 1,4-anthraquinonediyl diether, and the reaction proceeded with 89% e.e. Desilylation and subsequent alkaline hydrolysis gave (2S, 3R)-(+)-piscidic acid. The optical purity was increased to >99% e.e. by recrystallization. The use of dihydroquinine 1,4-anthraquinonediyl diether enable (2R, 3S)-(-)-piscidic acid to be obtained. In the asymmetric dihydroxylation of the (E)-olefin, phthalazine ligands (dihydroquinidine and dihydroquinine 1,4-phthalazinediyl diethers) gave high e.e. values. Via the same deprotection procedure, (2S, 3S)-(+)-3-epi-piscidic acid and (2R, 3R)-(-)-2-epi-piscidic acid were respectively obtained.
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Organic Chemistry Notes
Organic Chemistry Preliminary Communication
Biochemistry & Molecular Biology Regular Papers
  • Norihiro MITSUKAWA, Ryoichi KONISHI, Masato UCHIKI, Takehiro MASUMURA, ...
    1999 Volume 63 Issue 11 Pages 1851-1858
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      An alcohol-soluble storage protein, a 16.6-kDa prolamin found in rice seeds, was purified from both the total protein body and purified type I protein body fractions. The partial amino acid sequences of three tryptic peptides generated from the purified polypeptide were analyzed. A part of the 16.6-kDa prolamin cDNA was amplified from developing seed mRNA by the reverse transcribed polymerase chain reaction using an oligo (dT) primer and a primer which was synthesized based on the partial amino acid sequence. The amplified product was used to isolate the full-length cDNA clone (λRP16) from a developing seed cDNA library. The cDNA has an open reading frame encoding a hydrophobic polypeptide of 149 amino acids. The polypeptide was rich in glutamine (20.0%), cysteine (10.0%), and methionine (6.9%). The cysteine content was higher than those of most other rice storage proteins. Messenger RNA of the 16.6-kDa prolamin was detected in seeds, but not in other aerial tissues.
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  • Ileana Cornelia FARCASANU, Dai HIRATA, Eiko TSUCHIYA, Keiko MIZUTA, To ...
    1999 Volume 63 Issue 11 Pages 1871-1881
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      To identify new proteins involved in Mn2+ homeostasis, we isolated Mn2+-resistant mutants of Saccharomyces cerevisiae starting from a calcineurin-deficient, Mn2+ hypersensitive strain (Δcmp1 Δcmp2). The mutations were found to lie in the PMR1 gene, known to encode a “P-type” Ca2+-ATPase that transports Ca2+ and Mn2+ from the cytosol to the Golgi apparatus. A second gene, AHP1, was cloned as a suppressor of the Mn2+ tolerance of a Δcmp1 Δcmp2 pmr1 mutant. Ahp1p was recently described as a thioredoxin peroxidase type II, an antioxidant protein with alkyl hydroperoxide defense properties in yeast. AHP1 disruption in strain W303 decreased tolerance to Mn2+ and H2O2. We found that a GFP-Ahp1p fusion construct was in the cytosol when cells were grown in glucose, and in the mitochondria when cells were grown in oleate. Based on Mn2+ transport data, we concluded that Ahp1p is involved in cellular Mn2+ homeostasis in trafficking of Mn2+ from cytosol to mitochondria and from cytosol for export across the plasma membrane.
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  • Tetsuyuki ENTANI, Seiji TAKAYAMA, Megumi IWANO, Hiroshi SHIBA, Fang-Si ...
    1999 Volume 63 Issue 11 Pages 1882-1888
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Self-incompatibility in Solanaceae is controlled by a single multiallelic locus, the S-locus. The S-allele associated ribonucleases (S-RNases) in the pistil are involved in pollen rejection. In this work, we analyzed two newly isolated lines of Petunia hybrida, termed PB and PF. They both had the same set of S-RNases (SB1- and SB2-RNases), however the PB was a self-incompatible diploid while PF was a self-compatible tetraploid. Cross pollination tests between PB and PF indicated diploid pollen from PF lost the incompatibility phenotype. In order to clarify the effects of polyploidy on pollen phenotypic change, we artificially induced tetraploid plants from a diploid SB1SB2 heterozygote (=PB) and a diploid SB1SB1 homozygote. The obtained SB1SB1SB1SB1 homoallelic tetraploid remained self-incompatible, whereas the SB1SB1SB2SB2 heteroallelic tetraploid became self-compatible. These data suggested that the diploid heteroallelic pollen lost the incompatibility phenotype and had the characteristics of self-compatibility with SB1SB2 style.
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  • Shigeru SAKAJO, Nobuko MINAGAWA, Akio YOSHIMOTO
    1999 Volume 63 Issue 11 Pages 1889-1894
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      To investigate the regulatory mechanism of alternative oxidase gene expression, genomic DNA was cloned from the yeast Pichia anomala. Genomic Southern blot analysis suggested that a single copy nuclear gene encoded an alternative oxidase in the yeast. The nucleotide sequence showed an uninterrupted coding region for the alternative oxidase protein. In the upstream region from the transcription initiation site found by primer extension analysis, CCAAT, TATAA, and UAS2-like elements were detected. The UAS2 is the element involved in transcriptional regulation by carbon source and the target site for the factor, HAP2/3/4/5 protein complex, in Saccharomyces cerevisiae. By a gel mobility shift assay, a specific retardation band was detected when a protein extract from cells grown on an inducing carbon source was incubated with a UAS2-containing probe. These results suggest that carbon source regulation of alternative oxidase gene expression is mediated by the UAS2-like element and a HAP-like factor in P. anomala.
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  • Yasuyuki ARAKANE, Daizo KOGA
    1999 Volume 63 Issue 11 Pages 1895-1901
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      A new chitinase isozyme (Chitinase A), which had only one optimum pH toward a long substrate, glycolchitin, was purified from the peel of yam tuber by CTAB (hexadecyl trimethyl ammonium bromide) treatment and ammonium sulfate fractionation, followed by column chromatography on DEAE-Cellulofine A-500, chromatofocusing, and gel filtration on Sephacryl S-100. The molecular weight was 28,000 by SDS-PAGE. The isoelectric point was 3.6. The optimum pH was 4.0 toward both a polymer substrate, glycolchitin, and an oligosaccharide substrate, GlcNAc5. The optimum temperature was 60°C. Chitinase A was stable between pH 6 and 11 and below 45°C. Kinetic analysis was done using a series of N-acetylchitooligosaccharides (GlcNAcn, n=2 to 6) and glycolchitin as the substrates. Chitinase A hydrolyzed N-acetylchitooligosaccharides in an endo/random fashion except the disaccharide, and released the monosaccharide from all hydrolyzed oligosaccharides. This enzyme preferred oligosaccharides with the longer chain lengths. Chitinase A was inhibited 76% by 55 μM allosamidin, which is known to be a specific inhibitor of insect chitinases.
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  • Daekyung KIM, Tatsuya ODA, Atsushi ISHIMATSU, Tsuyoshi MURAMATSU
    1999 Volume 63 Issue 11 Pages 1947-1952
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Chattonella marina is well known as the causative organism of red tide, and is highly toxic to fish. However, the toxic mechanism of C. marina has not been established. Recent studies demonstrated that C. marina generates reactive oxygen species (ROS) such as O2- and H2O2. In this study, we attempted to establish mutant strains of C. marina using a chemical mutagen, ethyl methane sulfonate (EMS). After 48 h of treatment with 1 mg/ml of EMS at 26°C, several viable cells were cloned, while more than 90% of C. marina cells died under these conditions. Among the strains isolated, one strain (mutant C) was significantly decreased in the production of O2-, but its growth rate was indistinguishable from the parental C. marina. Furthermore, superoxide dismutase (SOD) had almost no effect on the proliferation of mutant C, while SOD suppressed the growth of parental C. marina. In accordance with the lower level of O2- generation, mutant C was less toxic to Vibrio alginolyticus in a plankton/bacteria co-culture system as compared to parental C. marina. In contrast, no significant difference in H2O2 production between mutant C and parental C. marina was observed. These results may provide experimental evidence for a direct connection between the toxic effect of C. marina against V. alginolyticus and the production of superoxide anion. Although the detailed mechanism of the production of superoxide anion by C. marina is still unclear, our mutant strain isolated in this study may be a good tool for the clarification of the mechanism of O2- generation by C. marina.
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  • Motoyuki TAGASHIRA, Naoko NOZATO, Seiji ISONISHI, Aikou OKAMOTO, Kazun ...
    1999 Volume 63 Issue 11 Pages 1953-1958
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      To search for compounds that reverse the drug resistance induced by glutathione (GSH), an original screening system to detect intracellular GSH depleters was established. Among 8843 microbes derived from the soil samples tested, the extracts of two Streptomyces species, named KS6701 and KS8846, lowered the intracellular GSH level of Saccharomyces cerevisiae 5×47. From both the microbes, 5-hydroxy-4-oxo-L-norvaline (HON) was isolated as the active compound. At a concentration of 50-100 μg/ml, HON also decreased the GSH/protein level of the human ovarian tumor cell line, 2008/C13*5.25 and reversed its resistance to cisplatin. We also investigated the mechanism of the depletion. HON had little effect on γ-glutamylcysteine synthetase (γ-GCS) or glutathione synthetase, but HON decreased the quantity of thiol substances when it was spontaneously reacted with them. This suggested that the GSH depletion by HON occurred through a mechanism different from that of buthionine sulfoximine, a selective γ-GCS inhibitor.
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  • Kazuya MITSUHASHI, Midori YAMASHITA, Yeo Soo HWAN, Fumio IHARA, Takuya ...
    1999 Volume 63 Issue 11 Pages 1959-1964
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      A new lipase (OBase) which efficiently hydrolyzes oleyl benzoate (OB) was found in the culture supernatant of Acinetobacter nov. sp. strain KM109, a new isolate growing in a minimum medium containing OB as the sole carbon source. OBase was purified to homogeneity with 213-fold purification and 0.8% yield. The molecular weight was estimated to be 62,000±1,000 by SDS-PAGE under denatured-reduced conditions and to be 50,000±1,000 by gel-filtration HPLC under native conditions; these findings indicate that OBase is a monomeric enzyme. The optimum temperature and pH of OBase were about 45°C and pH 8. Temperature and pH stabilities were at or lower than 35°C and in a range of pH 6-8, respectively. Purified OBase preferentially hydrolyzed p-nitrophenyl benzoate (pNPB) over p-nitrophenyl acetate (pNPA) or p-nitrophenyl caproate (pNPC) [pNPB/pNPA=20 and pNPB/pNPC=5.4], indicating that OBase has a high affinity for benzoyl esters. Partial amino-acid sequences of OBase fragments obtained after lysyl endopeptidase treatment showed no similarity with known proteins.
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  • Chitoshi OKA, Masao TANAKA, Michiro MURAKI, Kazuaki HARATA, Katsunori ...
    1999 Volume 63 Issue 11 Pages 1977-1983
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      To get high level secretion of human lysozyme in Pichia pastoris, the following three signal sequences and one prepro sequence were evaluated: chicken lysozyme signal peptide, leucine-rich artificial signal peptide, Saccharomyces invertase signal peptide, and Saccharomyces prepro sequence of alpha factor (MF-α Prepro).
      Transformants harboring a lysozyme gene with MF-α Prepro secreted 20-fold more lysozyme than those harboring the lysozyme gene with any one of the other three signal sequences. Three mutant leader sequences derived from MF-α Prepro were constructed to discover the function of the pro region. The secretion was dramatically decreased by eliminating the pro region of MF-α Prepro. In contrast, MF-α Prepro with the EAEAEA sequence directed the secretion of an equivalent level of lysozyme having the extra amino acids (EAEAEA) in its N-terminus.
      For the effective secretion of native human lysozyme, MF-α Prepro without any spacer sequences was most suitable. The secreted protein by MF-α Prepro construct was identical with the authentic human lysozyme, judging from N-terminal amino acid sequencing and molecular mass spectrometric and crystallographic analysis.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Preliminary Communication
Food & Nutrition Science Regular Papers
  • Keiko KOHAMA, Takashi NAGASAWA, Naoyuki NISHIZAWA
    1999 Volume 63 Issue 11 Pages 1921-1926
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Seed protein of foxtail and proso millets were fractionated into polypeptides that were analyzed for their major protein, prolamin, and the NH2-terminal amino acid sequences of the proteins were determined. The proteins extracted from foxtail and proso millets were 64.1% and 80.0% prolamin, respectively. The polypeptides of the prolamins were classified into two groups. The major polypeptides of 27-19 kDa were rich in leucine and alanine, whereas the 17-14 kDa polypeptides were rich in methionine and cysteine. Glutelin-like proteins that were extracted with a reducing reagent were high in proline content, the major polypeptides being 17 and 20 kDa. The NH2-terminal amino acid sequence showed that the major polypeptides of prolamin were homologous to α-zein and a glutelin-like protein containing the Pro-Pro-Pro sequence, like the repetitive sequence of γ-zein. Although the prolamin consisted of a similar subunit to that of zein, polypeptides with various pI values were found among them.
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  • Wataru HASHIMOTO, Keiko MOMMA, Hye-Jin YOON, Sachiko OZAWA, Yasunobu O ...
    1999 Volume 63 Issue 11 Pages 1942-1946
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Feeding studies of transgenic potatoes with native and designed soybean glycinins in rats were done for four weeks. The designed glycinin has four additional methioninyl residues in the middle of the glycinin molecule. Rats were divided into four groups fed (I) only a commercial diet, (II) the diet plus non-transgenic potatoes, (III) the diet plus transgenic potatoes with native glycinin, and (IV) the diet plus transgenic potatoes with designed glycinin. Rats were fed 2,000 mg/kg-weight potatoes every day by oral administration. During the period tested, rats in each group (groups II, III, and IV) grew well without marked differences in appearance, food intake, body weight, or in cumulative body weight gain. No significant differences were also found in blood count, blood composition, and in internal organ weights among the rats after feeding potatoes (groups II, III, and IV) for four weeks. Necropsy at the end of experiment indicated neither pathologic symptoms in all rats tested nor histopathological abnormalities in liver and kidney. Judging from these results, the transgenic potatoes with glycinins are confirmed to have nearly the same nutritional and biochemical characteristics as non-transgenic one.
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  • Hideki MOCHIZUKI, Jun TAKIDO, Hiroaki ODA, Hidehiko YOKOGOSHI
    1999 Volume 63 Issue 11 Pages 1984-1987
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The effect of dietary taurine on hypercholesterolemia induced by a high-cholesterol diet in streptozotocin (STZ)-induced diabetic rats was investigated. The concentrations of serum and liver cholesterol were markedly elevated in STZ-diabetic rats fed on the cholesterol-containing diet, and dietary taurine significantly reduced this elevated level of cholesterol in the serum and liver. The gene expression of cholesterol 7α-hydroxylase (CYP7A1), which is the rate-limiting enzyme for cholesterol degradation, was induced by the supplementation of taurine to the high-cholesterol diet. It is suggested that one of the reasons for this hypocholesterolemic action by taurine might have been the enhancement of cholesterol degradation.
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Food & Nutrition Science Notes
  • Tamako NISHIIKE, Jun ICHIKAWA, Noriko KIKUGAWA, Hitoshi TAKAMURA, Teru ...
    1999 Volume 63 Issue 11 Pages 1997-2000
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Although lipid hydroperoxides are known to decrease food quality and safety, the stability of hydroperoxides in foods has hardly been investigated. We examined HPOD decomposition by kinetic means with or without various food components. Most amino acids, especially lysine, arginine and tryptophan, stabilized HPOD, while cysteine and ascorbic acid accelerated its decomposition. Sugars has little effect. According to activation energy calculations, it was found that the HPOD decomposition mechanism in reaction systems with various food components was similar to that in water.
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  • Yoritaka AOYAMA, Mizuho WADA
    1999 Volume 63 Issue 11 Pages 2005-2008
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The effects of orotic acid supplementation to casein, egg protein, soy protein and wheat gluten diets on the lipids of liver and serum were compared. When orotic acid was added, the contents of total lipids and triacylglycerol in the liver of the casein group were significantly higher or tended to be higher than those of the other three dietary groups. Dietary orotic acid had no effect on the food intake. The liver weight, and liver total lipids, triacylglycerol, cholesterol and phospholipids were increased or tended to be increased by the addition of orotic acid. The serum triacylglycerol level was decreased by the addition of orotic acid to either the casein or soy protein diet. Thus, the response to liver lipid accumulation induced by orotic acid feeding depended on the dietary protein type.
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  • Hwan-Sook SEO, Yasushi ENDO, Kenshiro FUJIMOTO
    1999 Volume 63 Issue 11 Pages 2009-2010
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The oxidation rates for conjugated linoleic acid (CLA), linoleic acid (LA), and their methyl and ethyl esters were measured in aqueous and solvent systems by the induction period method. In an aqueous system, the initiation rate was almost the same for all the samples, except for ethyl conjugated linoleate (ECL). The propagation rate, oxidizability, and kinetic chain length were different for the ester and free types of CLA and LA. CLA was the most stable, its oxidizability being half that of LA. However, ECL was very susceptible to free radical oxidation. In a solvent system, the CLA derivatives had higher or almost same oxidizability as the LA derivatives, although the propagation rates of CLA and LA were lower than those of their esters.
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  • Hiroaki SAITO, Rieko YAMASHIRO, Kenji ISHIHARA, Changhu XUE
    1999 Volume 63 Issue 11 Pages 2028-2030
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The fatty acid composition of the total lipids in ordinary muscle and of the stomach contents of the three highly migratory fish species, Euthynnus affinis (Temminck et Schlegel), Sarda orientalis (Canter), and Elagatis bipinnulata (Quoy et Gaimard), was determined. DHA was the dominant fatty acid among the polyunsaturated fatty acids in the tissue lipids of the three fish species and the DHA levels in the lipids of the muscles were comparatively high, while those in the stomach contents originating from their prey were generally low.
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Microbiology & Fermentation Technology Regular Papers
  • Keiko SASAKI-IGAWA, Tetsuya SATO, Hiroshi MASUDA, Takuji OHWADA
    1999 Volume 63 Issue 11 Pages 1859-1864
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The growth of Bradyrhizobium japonicum as well as Rhizobium leguminosarum bv. phaseoli growing in minimal medium was repressed by the addition of hydroxylysine (Hyl), although the sensitivity of the former to Hyl seemed to be lower than that of the latter. The nodulation efficiency of both Glycine max (L.) inoculated with B. japonicum cells and Phaseolus vulgaris (L.) inoculated with R. leguminosarum bv. phaseoli cells was reduced in the presence of Hyl, concomitantly with the decrease in the elongation of roots. Besides, the Hyl contents in the seed (seedling) exudates tended to increase when the host plants were inoculated with an unfavorable strain for their nodulation. These results suggest that the Hyl plays a role in the effective symbiotic relationship by regulating the growth of the root nodule bacteria on the root surface and/or the elongation of the host plant’s roots.
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  • Elisa ALVAREZ-MACARIE, Valerie AUGIER-MAGRO, Jacques BARATTI
    1999 Volume 63 Issue 11 Pages 1865-1870
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      A new esterase activity from Bacillus licheniformis was characterized from an Escherichia coli recombinant strain. The protein was a single polypeptide chain with a molecular mass of 81 kDa. The optimum pH for esterase activity was 8-8.5 and it was stable in the range 7-8.5. The optimum temperature for activity was 45°C and the half-life was 1 h at 64°C. Maximum activity was observed on p-nitrophenyl caproate with little activity toward long-chainfatty acid esters. The enzyme had a KM of 0.52 mM for p-nitrophenyl caproate hydrolysis at pH 8 and 37°C. The enzyme activity was not affected by either metal ions or sulfydryl reagents. Surprisingly, the enzyme was only slightly inhibited by PMSF. These characteristics classified the new enzyme as a thermostable esterase that shared similarities with lipases. The esterase might be useful for biotechnological applications such as ester synthesis.
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  • Tamotsu NISHIDA, Akira NAKAMURA, Haruhiko MASAKI, Takeshi UOZUMI
    1999 Volume 63 Issue 11 Pages 1902-1909
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      The expression of the cyclodextrin glucanotransferase (CGTase) gene (cgt) of Bacillus ohbensis, when introduced into an α-amylase-defective strain of B. subtilis on a multicopy plasmid, pHY300PLK, was induced in the presence of starch and was subject to catabolite repression by glucose as well as in the original strain, B. ohbensis. We constructed a cgt´::´lacZ translational fusion to study the expression in B. subtilis, and this construct was confirmed to be subject to both starch induction and catabolite repression. In order to define the region involved in the regulation of the cgt gene, a series of cgt´::´lacZ gene with various lengths of deletion in the promoter region was constructed on pHY300PLK. DNA regions responsible for starch induction and catabolite repression by glucose could be separated in the deletion experiment. Primer extension analysis showed that the catabolite repression was controlled at the initiation of transcription, while the starch induction is likely to be controlled by a transcriptional termination-antitermination mechanism.
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  • Toshihiko TAKEHANA, Sakura INOUE, Ryo TAKEI, Hiroyuki ITO, Hirokazu MA ...
    1999 Volume 63 Issue 11 Pages 1927-1933
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Four strains of acid-tolerant and protein-using bacteria were isolated from compost. Two of them, Gram-negative strains MB8 and MB11, were identified as a new genus close to Stenotrophomonas species MB8 and Burkholderia species MB11, respectively. Both bacteria produced extracellular carboxyl proteases (CP) in acid-casein-starch medium. The enzymes, termed CP MB8 and CP MB11, purified through ion exchange and gel filtration chromatographies had molecular weights of 61,000 (CP MB8) and 36,000 (CP MB11) as estimated by SDS-PAGE, and showed optimum activities with hemoglobin as a substrate at pH 3.5 (CP MB8) and pH 3.7 (CP MB11) at 55°C. Both of the enzymes were not inhibited by pepstatin, DAN, or EPNP. These results suggest that both enzymes are members of the pepstatin-insensitive carboxyl proteinase family (EC 3.4.23.33), except for a larger molecular weight of the CP MB8 enzyme.
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  • Akira MIYAUCHI, Makoto OZAWA, Makoto MIZUKAMI, Kouji YASHIRO, Shogo EB ...
    1999 Volume 63 Issue 11 Pages 1965-1969
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Brevibacillus choshinensis (Bacillus brevis) HPD31 is a very efficient producer of recombinant human epidermal growth factor (EGF). The produced EGF is secreted into the medium with high efficiency. However part of the EGF that accumulates in the medium, exists as multimeric forms which are biologically inactive. We found the bacterium has the activity to structurally convert multimeric forms to the monomeric, native ones. Optimal temperature and pH for the conversion were 40°C and pH 9, respectively. The reaction was promoted in the presence of reduced glutathione or cysteine. But the cells which had been sonicated or exposed to moderate heat treatment completely lost the activity. Thus, it was presumed that the activity might be due to the enzyme(s) that catalyze the protein disulfide exchanging reaction, and that they resides on the surface of viable cells.
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  • Hidetoshi KOJIMA, Hitoshi HASHIMOTO, Koji YODA
    1999 Volume 63 Issue 11 Pages 1970-1976
    Published: 1999
    Released: March 08, 2005
    JOURNALS FREE ACCESS
      Saccharomyces cerevisiae Mnn9 protein is a type II Golgi membrane protein which concerns in protein mannosylation. When solubilized by Triton X-100, it was recovered in two distinct complexes both having mannosyltransferase activity; one with Van1 protein (V-complex) and the other with Anp1, Hoc1, Mnn10, and Mnn11 proteins (A-complex). Characterization of the null mutants suggested that A-complex is also concerned in protein O-glycosylation. A-complex was more resistant than V-complex to dissociating conditions. Interaction between the lumenal domains of Van1 and Mnn9 was detected by a two-hybrid experiment. The anchor domain of Mnn9 protein could be replaced with other membrane anchors without losing the ability to form complexes similar to V- and A-complexes. Thus the lumenal domains are important to assemble these distinct complexes.
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Microbiology & Fermentation Technology Note
Microbiology & Fermentation Technology Preliminary Communication
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