Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 68 , Issue 6
Showing 1-39 articles out of 39 articles from the selected issue
Review
Organic Chemistry Regular Papers
Organic Chemistry Notes
  • Tsunashi KAMO, Yuki IMURA, Tomomi HAGIO, Hidefumi MAKABE, Hisao SHIBAT ...
    2004 Volume 68 Issue 6 Pages 1362-1365
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Four novel diterpenoids were isolated from the fruiting bodies of Sarcodon scabrosus (Fr.) Karst. (Boraginaceae) together with neosarcodonin A. One of the novel compounds was elucidated to be a cyathane diterpenoid, namely neosarcodonin O, by its spectral data. The others were characterized as 19-O-linoleoyl, 19-O-oleoyl and 19-O-stearoyl derivatives of sarcodonin A, after comparison with the authentic samples synthetically prepared from sarcodonin A. These compounds, together with the five 19-O-acyl derivatives synthesized from sarcodonin A, each exhibited inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation on mouse ears by topical application.
    Download PDF (90K)
  • Sun PARK, Yuuko TAKANO, Hideyuki MATSUURA, Teruhiko YOSHIHARA
    2004 Volume 68 Issue 6 Pages 1366-1368
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    A maize plant (Zea mays) planted in a test tube was found to inhibit the growth of the soil-borne plant pathogen, Fusarium oxysporum f. sp. melongenae. The antifungal compounds, 6-methoxybenzoxazolinone and 6,7-dimethoxybenzoxazolinone, were isolated from an ethanol extract of Zea mays roots, and (6R)-7,8-dihydro-3-oxo-α-ionone and (6R,9R)-7,8-dihydro-3-oxo-α-ionol were isolated from the root exudate.
    Download PDF (111K)
  • Akira HIROTA, Miyuki INABA, Yu-Chi CHEN, Naoki ABE, Shoji TAKI, Masami ...
    2004 Volume 68 Issue 6 Pages 1372-1374
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We isolated from soybean miso 8-hydroxyglycitein and 6-hydroxydaidzein as DPPH-radical scavengers, and elucidated their chemical structures by mass spectrometric, and 1H- and 13C-NMR spectrosopic analyses. These compounds showed DPPH-radical scavenging activity as high as that of α-tocopherol, 8-hydroxygenistein and 8-hydroxydaidzein. This is the first report of the isolation of 8-hydroxyglycitein from a natural source.
    Download PDF (79K)
Organic Chemistry Communication
Biochemistry & Molecular Biology Regular Papers
  • Diah RACHMAWATI, Takehiko HOSAKA, Eiichi INOUE, Hiroyuki ANZAI
    2004 Volume 68 Issue 6 Pages 1193-1200
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    The Agrobacterium-mediated transformation system was extended to a famous Javanica rice variety, Rojolele, that is cultivated in Indonesia now. Efficient callus induction from immature and mature seeds of Rojolele did not succeed by any previous method for any rice cultivar. In this study, the callus from mature seeds of Rojolele exhibited a compact and nodular appearance on C medium after the carbon source and medium pH was modified. Scutellum-derived calli from mature seeds were co-cultivated with Agrobacterium tumefaciens strains EHA101 or LBA4404 that carried plasmid pAFT14, which contained the genes for β-glucuronidase (gus) and hygromycin resistance (hpt). Finally, the transformation efficiency of Rojolele variety using A. tumefaciens strain EHA101 (pAFT14) was improved to about 23%, similar to that of the Japonica rice variety Nipponbare. The seed fertility of transgenic Rojolele was more than 90%. The copy number of the transgene varied from one to three copies in the T0 transgenic lines. Both the gus and the hpt genes were inherited and expressed in the progeny.
    Download PDF (365K)
  • Do-Youn LEE, Sang-Soo LEE, Won-A JOO, Eun-Ju LEE, Chan-Wha KIM
    2004 Volume 68 Issue 6 Pages 1201-1208
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    BPA, bisphenol A, a monomer of epoxy resins and polycarbonate plastic, is used in many consumer products including the plastic linings of cans for food and babies’ bottles. BPA has been reported to cause reproductive toxicity and affects cells in rats and mice at high doses. In this study, the effect of BPA on protein expression in TM4 cells (a mouse Sertoli cell line) known to play an essential role in Spermatogenesis was investigated by two-dimensional electrophoresis (2-DE). After 16 h exposure to 50, 100, 150, 200, and 250 μM of BPA, the viability of TM4 cells decreased to about 90, 85, 78, 55, and 30% of control respectively. Approximately 800 protein spots in TM4 cells were analyzed by 2-DE with pH 4–7 linear immobilized pH gradient (IPG) Dry Strip, and 11 proteins which showed significantly different expression levels were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Among these, HSP 27 and placental calcium binding protein may be proteins differentially expressed by BPA exposure.
    Download PDF (278K)
  • Ken-ichi TAKEYAMA, Saya ITO, Shun SAWATSUBASHI, Yuko SHIRODE, Ayako YA ...
    2004 Volume 68 Issue 6 Pages 1209-1215
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Androgen receptor (hAR) regulates transcription of target genes in a ligand-dependent manner and recruits a number of co-activators for the ligand-induced transactivation via the N-terminal, activation function-1 (AF-1), and C-terminal, AF-2, transactivation domains. But the co-regulator functions on each of AR domains have not yet been fully understood. We have established a Drosophila transgenic system in which hAR and its deletion mutants are ectopically expressed in fly tissues together with an AR response element (ARE)-GFP reporter gene, and have confirmed that hAR was functional in ARE transactivation without affecting the expression of endogenous genes. We found that transcriptional activity of the hAR AF-1 domain was markedly reduced in Drosophila deficiency mutants of homologs for known mammalian co-activators of the AR ligand-dependent AF-2 domain. This suggests that hAR AF-1 recruits co-activators previously known only to interact with the AF-2 domain. Therefore, Drosophila with the hAR AF-1 transgene provides a relevant genetic system in which to uncover novel functions of vertebrate steroid hormone receptors and to screen for novel AF-1 co-regulators.
    Download PDF (326K)
  • Tetsuya SATOH, Junichi KATO, Noboru TAKIGUCHI, Hisao OHTAKE, Akio KURO ...
    2004 Volume 68 Issue 6 Pages 1216-1220
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We developed an ultrasensitive bioluminescence assay of ATP by employing (i) adenylate kinase (ADK) for converting AMP+ATP to two molecules of ADP, (ii) polyphosphate (polyP) kinase (PPK) for converting ADP back to ATP (ATP amplification), and (iii) a commercially available firefly luciferase. A highly purified PPK-ADK fusion protein efficiently amplified ATP, resulting in high levels of bioluminescence in the firefly luciferase reaction. The present method, which was approximately 10,000-fold more sensitive to ATP than the conventional bioluminescence assay, allowed us to detect bacterial contamination as low as one colony-forming unit (CFU) of Escherichia coli per assay.
    Download PDF (89K)
  • Osmundo Brilhante DE OLIVEIRA NETO, João Aguiar Nogueira BATIST ...
    2004 Volume 68 Issue 6 Pages 1235-1242
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    The cotton boll weevil (Anthonomus grandis) causes severe cotton crop losses in North and South America. This report describes the presence of cysteine proteinase activity in the cotton boll weevil. Cysteine proteinase inhibitors from different sources were assayed against total A. grandis proteinases but, unexpectedly, no inhibitor tested was particularly effective. In order to screen for active inhibitors against the boll weevil, a cysteine proteinase cDNA (Agcys1) was isolated from A. grandis larvae using degenerate primers and rapid amplification of cDNA ends (RACE) techniques. Sequence analysis showed significant homologies with other insect cysteine proteinases. Northern blot analysis indicated that the mRNA encoding the proteinase was transcribed mainly in the gut of larvae. No mRNA was detected in neonatal larvae, pupae, or in the gut of the adult insect, suggesting that Agcys1 is an important cysteine proteinase for larvae digestion. The isolated gene will facilitate the search for highly active inhibitors towards boll weevil larvae that may provide a new opportunity to control this important insect pest.
    Download PDF (180K)
  • Katsumi WATANABE, Naoko NISHIDA, Takashi ADACHI, Motoko UEDA, Toshio M ...
    2004 Volume 68 Issue 6 Pages 1243-1248
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Changes in the levels of thiamin-binding globulin and thiamin in wheat seeds during maturation and germination were studied. The thiamin-binding activity of the seed proteins increased with seed development after flowering. The thiamin content of the seeds also increased with development. Thiamin-binding activity decreased during seed germination. On the other hand, immunological analysis using an antibody directed against the thiamin-binding protein isolated from wheat seeds showed that the thiamin-binding globulin accumulated in the aleurone layer of the seeds during maturation, and then the protein was degraded and disappeared during seed germination. These results suggested that the thiamin-binding globulin of wheat seeds was synthesized and accumulated in the aleurone layer of the seeds with seed development, similar to the thiamin-binding albumin in sesame seeds, and that thiamin bound to the thiamin-binding globulin in the dormant wheat seeds for germ growth during germination.
    Download PDF (487K)
  • Hisashi TAKEDA, Naho HARA, Masayuki SAKAI, Akihiro YAMADA, Keisuke MIY ...
    2004 Volume 68 Issue 6 Pages 1249-1258
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Five transcriptional promoters of biphenyl-degradation genes in Rhodococcus sp. RHA1 were characterized. We newly identified the etbA4 promoter region, which was located adjacent upstream from a ferredoxin reductase gene, etbA4 and a dihydrodiol dehydrogenase gene, bphB2. The etbA4 promoter activity was determined in RHA1 using a promoter probe vector with a luxAB luciferase reporter gene, and was induced by a variety of aromatic compounds as well as the bphA1, ebdA1, etbA1, and etbD1 promoters. All these promoters were induced by aromatic compounds in a closely related heterologous host, R. erythropolis IAM1399 in the presence of RHA1 bphST genes, suggesting that these five promoters are under the control of bphST-coding two-component regulatory system. Sequence comparison of the bphA1 promoter with the ebdA1 and etbA1 promoters, whose transcription starts were determined by primer extension analysis, revealed a consensus sequence centering 42-bp upstream from the transcription start. This consensus was also conserved in the etbA4 and etbD1 promoters, and deletions of the bphA1 promoter affecting the consensus impaired inducible promoter activity. These results suggest that this consensus plays a role in transcription induction and/or the promotion of biphenyl degradation genes in RHA1.
    Download PDF (395K)
  • Tomonori SHINYA, Shinobu GONDO, Hiroshi IIJIMA, Kazunari HANAI, Hideak ...
    2004 Volume 68 Issue 6 Pages 1265-1272
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Stress-induced cell-lytic activity was found in tobacco BY-2 cells treated with various stresses. Among 14 stresses, an elicitor fraction isolated from Alternaria alternata showed the highest inducing activity. Cell-lytic activity increased for 72 h even in the control sample, treated with distilled water, and several isozymes of β-1,3-glucanases and chitinases were found to be involved in it. In contrast, cell-lytic activity in BY-2 cells treated with a fungal elicitor reached a higher level after 60 h. The principal enzymes specifically involved in this stress-induced portion are speculated to be basic β-1,3-glucanases. A class I β-1,3-glucanase gene (glu1) was found to be the specific gene for the stress-induced cell-lytic activity. Its expression became observable at 24 h, and the intensity reached a maximum at about 60–72 h. The glu1 was thus assigned as a late gene. Its role in the stress response is discussed in conjunction with earlier genes such as chitinases.
    Download PDF (205K)
  • Xiaohua XU, Orie KASHIMA, Akira SAITO, Hiroyuki AZAKAMI, Akio KATO
    2004 Volume 68 Issue 6 Pages 1273-1278
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Two serine-rich heptapeptides, Ser-Ser-Ser-Lys-Ser-Ser-Ser (S6K) and Ser-Ser-Ser-Ser-Ser-Ser-Ser (S7), were fused to the C-terminus of chicken lysozyme (Lz) by genetic modification to improve the functional properties of lysozyme. The cDNAs of S6K-lysozyme (S6K-Lz) and S7-lysozyme (S7-Lz) were inserted into the expression vector of Pichia pastoris and secreted in yeast cultivation medium. The secretion amounts of S6K-Lz and S7-Lz were about 60% of that of wild-type lysozyme (Wt-Lz). The CD spectra showed that the conformation of S6K-Lz and S7-Lz was conserved regardless of the attachment of serine-rich peptides. The denaturation curves of S6K-Lz and S7-Lz also showed that the conformational changes were very small. The lytic activity of S6K-Lz and S7-Lz was almost the same as that of Wt-Lz, while the bactericidal activity against Escherichia coli of S6K-Lz and S7-Lz was greatly increased. The acetic acid-urea PAGE of phosphatase-treated S6K-Lz and S7-Lz indicated the possibility of phosphorylation of the fused serine-rich heptapeptides.
    Download PDF (132K)
  • Masanobu DESHIMARU, Shingo YOSHIMI, Seijiro SHIOI, Shigeyuki TERADA
    2004 Volume 68 Issue 6 Pages 1279-1286
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Genes for Bowman–Birk type protease inhibitors (BBIs) of wild soja (Glycine soja) and soybean (Glycine max) comprise a multigene family. The organization of the genes for wild soja BBIs (wBBIs) was elucidated by an analysis of their cDNAs and the corresponding genomic sequences, and compared with the counterparts in the soybean. The cDNAs encoding three types of wild soja BBIs (wBBI-A, -C, and -D) were cloned. Two subtypes of cDNAs for wBBI-A, designated wBBI-A1 and -A2, were further identified. Similar subtypes (sBBI-A1 and -A2) were also found in the soybean genome. cDNA sequences for wBBIs were highly homologous to those for the respective soybean homologs. Phylogenetic analysis of these cDNAs demonstrated the evolutional proximity between these two leguminae strains.
    Download PDF (350K)
  • Akiyoshi TANAKA
    2004 Volume 68 Issue 6 Pages 1293-1298
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    The acid-induced denaturation of wild-type Staphylococcal nuclease (WT) and its eight mutant forms, L25A, V66L, G79S, A90S, G88V, H124L, V66L/G88V, and V66L/G79S/G88V, was investigated using Trp140 fluorescence as a probe at 30 °C. The values of pH1⁄2, at which the denaturation is half completed, and n, the apparent number of protons which trigger the denaturation and are taken up by the proteins upon denaturation at pH1⁄2, were evaluated from the pH dependence of the fluorescence intensity. The values of pH1⁄2 and n for WT were 3.8 and 1.8 respectively. The amino acid replacements changed the pH1⁄2 values to a range between 3.0 (H124L) and 4.4 (G79S) and also changed the n values to a range between 1.0 (A90S) and 3.0 (G88V). There was a negative correlation between the values of pH1⁄2 and n. It was suggested that the amino acid replacements may change the energy levels of the native state and/or the denatured state mainly in the neutral (stable) pH region, not in the acidic (unstable) region, resulting in the correlative changes in pH1⁄2 and n.
    Download PDF (111K)
  • Takahiro KUBOTA, Katsushiro MIYAMOTO, Masahide YASUDA, Yoshihiko INAMO ...
    2004 Volume 68 Issue 6 Pages 1306-1314
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We purified and characterized an intracellular β-N-acetylglucosaminidase (NagC) from a cytoplasmic fraction of Streptomyces thermoviolaceus OPC-520. The molecular mass of NagC was estimated to be 60 kDa by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of the enzyme were 6.0 and 50 °C respectively. Purified NagC hydrolyzed chitin oligosaccharides from N,N′-diacetylchitobiose (GlcNAc)2 to chitopentaose (GlcNAc)5, hydrolyzed N,N′-diacetylchitobiose especially rapidly, and showed a tendency to decrease with increases in the degree of polymerization. But, NagC didn’t hydrolyze chitohexaose (GlcNAc)6. The gene encoding NagC was cloned and sequenced. The open reading frame of nagC encoded a protein of 564 amino acids with a calculated molecular mass of 62,076 Da. The deduced amino acid sequence of NagC showed homology with several β-N-acetylglucosaminidases belonging to glycosyl hydrolase family 20. The expression plasmid coding for NagC was constructed in Escherichia coli. The recombinant enzyme showed pH and temperature optima and substrate specificity similar to those of the native enzyme. The gene arrangement near the nagC gene of S. thermoviolaceus OPC-520 was compared with that of S. coelicolor A3(2). Three genes, which appear to constitute an ABC transport system for sugar, were missing in the vicinity of the nagC gene.
    Download PDF (254K)
  • Tomoya YAMAGUCHI, Katsuhiro NAKAYAMA, Takami HAYASHI, Junshi YAZAKI, N ...
    2004 Volume 68 Issue 6 Pages 1315-1323
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Rice is most chilling sensitive at the onset of microspore release. Chilling treatment at this stage causes male sterility. The gene expression profile during the microspore development process under chilling stress was revealed using a microarray that included 8,987 rice cDNAs. As many as 160 cDNAs were up- or down-regulated by chilling during the microspore release stage. RT-PCR analysis of 5 genes confirmed the microarray results. We identified 3 novel genes whose expression levels were remarkably changed by chilling in rice anther. A new cis element that includes a DNA transposon Castaway sequence was found in the 5′ upstream region of two genes which were conspicuously down-regulated by chilling temperatures in rice anther.
    Download PDF (160K)
  • Shin-ichi ISHIKAWA, Yuki YANO, Keizo ARIHARA, Makoto ITOH
    2004 Volume 68 Issue 6 Pages 1324-1331
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Phosvitin, a phosphoprotein known as an iron-carrier in egg yolk, binds almost all the yolk iron. In this study, we investigated the effect of phosvitin on Fe(II)-catalyzed hydroxyl radical (OH) formation from H2O2 in the Fenton reaction system. Using electron spin resonance (ESR) with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and deoxyribose degradation assays, we observed by both assays that phosvitin more effectively inhibited OH formation than iron-binding proteins such as ferritin and transferrin. The effectiveness of phosvitin was related to the iron concentration, indicating that phosvitin acts as an antioxidant by chelating iron ions. Phosvitin accelerates Fe(II) autoxidation and thus decreases the availability of Fe(II) for participation in the OH-generating Fenton reaction. Furthermore, using the plasmid DNA strand breakage assay, phosvitin protected DNA against oxidative damage induced by Fe(II) and H2O2. These results provide insight into the mechanism of protection of the developing embryo against iron-dependent oxidative damage in ovo.
    Download PDF (144K)
  • Shuji KARASUDA, Kosuke YAMAMOTO, Michiko KONO, Shohei SAKUDA, Daizo KO ...
    2004 Volume 68 Issue 6 Pages 1338-1344
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    Kinetic analysis was done on the 46-kDa chitinase (EC 3.2.1.14) purified from the stomach of red sea bream, Pagrus major, using glycolchitin and N-acetylchitooligosaccharides (GlcNAcn, n=2–6) as substrates. High activity was observed at two pHs, such as 2.5 and 9.0, toward glycolchitin as seen in other insect chitinases, and also at both pH 2.5 and 5.0 even toward a short substrate, N-acetylchitopentasaccharide. Allosamidin competitively inhibited chitinase with Ki value of 0.0214 μM at pH 2.5 and 0.0024 μM at pH 9.0 in the reaction of glycolchitin. Substrate inhibition was observed in the reaction of N-acetylchitopentasaccharide. The anomeric forms of the products from N-acetylchitooligosaccharides were analyzed to be β anomer by the high pressure liquid chromatography (HPLC) method. The data for both β-anomer formation and allosamidin inhibition suggest that red sea bream chitinase belongs to family 18 of glycosyl hydrolases. This suggestion is also supported by the results for the N-terminal amino acid sequence.
    Download PDF (125K)
Biochemistry & Molecular Biology Notes
  • Yoshiaki YAMANO, Rio KAMON, Takao YOSHIMIZU, Yoshihisa TODA, Yuichi OS ...
    2004 Volume 68 Issue 6 Pages 1369-1371
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We constructed several mutant human MC4R cDNAs by site directed mutagenesis and expressed these receptors in COS-1 cells. The conserved DRY motif among GPCRs was mutated to generate eight mutants. While no MC4R ligand binding was detected in any of the mutants, one mutant, D146A, resulted in higher cAMP production in cells than the wild-type receptor without ligand stimulation.
    Download PDF (88K)
  • Terumichi TANAKA, Tomoaki ANDO, Shinnosuke HAGA, Yo KIKUCHI
    2004 Volume 68 Issue 6 Pages 1388-1392
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We prepared several mutants of the J3⁄4 and P4 domains of Escherichia coli ribonuclease P (RNase P): A62G, A62U, G63C/G64C, A65G, A67G, U69A, U69G, U69C, U69Δ, and U69UU. Comparison of the ribozyme and holo enzyme reactions at various concentrations of magnesium ions showed that the presence of a bulge at U69 in the P4 domain was important in the holo enzyme. The results also showed that the conserved bases G63 and G64 in the J3⁄4 domain were important for efficient ribozyme reactions but were replaceable in the presence of the protein component. Our data showed that the bases in the J3⁄4 and P4 domains displayed different responses to the metal ions that were affected by the presence of the protein component.
    Download PDF (267K)
  • Kazuyuki HIWATASHI, Kazuyuki HORI, Keitaro TAKAHASHI, Akira KAGAYA, Sh ...
    2004 Volume 68 Issue 6 Pages 1395-1397
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    We have found a novel prolyl aminopeptidase in Grifola frondosa. The enzyme was purified by DEAE-Sepharose CL-6B, Butyl-Toyopearl, Sephacryl S-100, and Mono-Q column chromatographies. The purified enzyme exists as a dimer and gives high activity toward L-proline-p-nitroanilide. The enzyme was strongly inhibited by p-chloromercuribenzoic acid and iodoacetic acid and markedly inhibited by phenylmethylsulfonyl fluoride and arphamenin A.
    Download PDF (62K)
Biochemistry & Molecular Biology Communication
  • Yukako SHIRASUKA, Ken-ichiro NAKAJIMA, Tomiko ASAKURA, Haruyuki YAMASH ...
    2004 Volume 68 Issue 6 Pages 1403-1407
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    A unique taste-modifying activity that converts the sense of sourness to the sense of sweetness occurs in the fruit of the plant Curculigo latifolia, intrinsic to West Malaysia. The active component, known as curculin, is a protein consisting of two identical subunits. We have found a new taste-modifying protein, named neoculin, of the same origin. Both chemical analysis and cDNA cloning characterized neoculin as a heterodimeric protein consisting of an acidic, glycosylated subunit of 113 amino acid residues and a basic subunit that is the monomeric curculin itself.
    Download PDF (99K)
Food & Nutrition Science Regular Papers
  • Yasuto YOSHIDA, Wakae YOKOI, Yasue WADA, Kenji OHISHI, Masahiko ITO, H ...
    2004 Volume 68 Issue 6 Pages 1185-1192
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    The hypocholesterolemic activities of 81 yeast strains were examined in rats fed a high cholesterol diet (HCD). Male Wistar rats were fed an HCD or an HCD supplemented with 10% yeast for 7 d. It was found that the hypocholesterolemic activities of the yeasts varied remarkably between strains. Kluyveromyces marxianus YIT 8292 exhibited the most potent hypocholesterolemic activity among the yeasts that were tested. K. marxianus YIT 8292 significantly decreased not only plasma total cholesterol but also liver total cholesterol when administered as a dietary admixture at a concentration of 3%. In contrast, brewer’s yeast and baker’s yeast, which have been predominantly used for food, did not exhibit hypocholesterolemic activity even when administered at a concentration of 10%. These results suggest that K. marxianus YIT 8292 may be utilized as a novel food material with the ability to contribute to the prevention of hypercholesterolemia.
    Download PDF (139K)
  • Shizuka SAITO, Yasuko OKAMOTO, Jun KAWABATA
    2004 Volume 68 Issue 6 Pages 1221-1227
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    DPPH radical scavenging reactions of protocatechuic acid and its methyl ester were investigated in various solvents. In alcoholic solvents, methyl protocatechuate rapidly scavenged more than four equivalents of the radical, whereas approximately two equivalents were consumed in aprotic solvents. Methyl, ethyl, butyl, isopropyl, and tert-butyl protocatechuates were examined for their DPPH radical scavenging abilities in methanol or ethanol. As a result, the radical scavenging equivalence of sterically bulky esters tended to decrease compared to that of methyl or ethyl ester. The ABTS radical scavenging ability of those esters in water also showed the same tendency. Since 2-methoxy derivatives were detected in the reaction mixture of methyl protocatechuate and DPPH radical in methanol, a nucleophilic attack of an alcoholic molecule on the o-quinone intermediate, which is sensitive to steric hindrance from alkyl groups of both esters and alcoholic solvents, must be crucial for total radical scavenging abilities.
    Download PDF (156K)
  • Hidemitsu UCHISAWA, Arata SATO, Junji ICHITA, Hajime MATSUE, Tomotada ...
    2004 Volume 68 Issue 6 Pages 1228-1234
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    The ornithine content of an extract of the brackish-water bivalve, Corbicula japonica, increased when the bivalve was frozen. It was not influenced by the period of freezing. This phenomenon was not apparent in the scallop, little-neck clam, or hard clam. We applied various low-temperature conditions for processing the bivalve from 4 °C to −10 °C and measured the ornithine content of each extract. The ornithine content was maximized by processing at −4 °C. The increase in this ornithine content was reduced when the bivalve was stored at 5 °C or 15 °C after processing at −4 °C, this decrease being reversed when the bivalve was again processed at −4 °C after warming. Low-temperature processing of the brackish-water bivalve therefore increased the ornithine content of the extract.
    Download PDF (138K)
Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Shigekazu YANO, Nopakarn RATTANAKIT, Mamoru WAKAYAMA, Takashi TACHIKI
    2004 Volume 68 Issue 6 Pages 1299-1305
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    KA-prep, a culture filtrate of Bacillus circulans KA-304 grown on a cell-wall preparation of Schizophyllum commune, has an activity to form protoplasts from S. commune mycelia. α-1,3-Glucanase, which was isolated from an ammonium sulfate fraction of 0–30% saturation of KA-prep, gave the protoplast-forming activity to an ammonium sulfate fraction of 30–50% saturation of KA-prep, which contained chitinase(s) and β-glucanase(s) but was inactive in the protoplast formation.
    Chitinase(s) and β-glucanase(s) in the ammonium sulfate fraction of 30–50% saturation were separated by DEAE-cellulofine A-500 column chromatography, and the protoplast-forming activity appeared when the chitinase preparation was mixed with the α-1,3-glucanase. The β-glucanase preparation was not effective for the protoplast formation whereas its addition enhanced the protoplast-forming activity of the mixture of α-1,3-glucanase and the chitinase preparation.
    The chitinase preparation contained two chitinases (chitinase I and II). Chitinase I showed the protoplast-forming activity with α-1,3-glucanase, but chitinase II did not. Chitinase I, a monomeric protein with a molecular weight of 41,000, was active toward colloidal chitin and ethylene glycol chitin. Chitinase I produced predominantly N,N′-diacetylchitobiose and N,N′,N″-triacetylchitotriose from colloidal chitin, and the enzyme was inactive to p-NP-β-D-N-acetylglucosaminide, suggesting that it was an endo-type enzyme. The N-terminal amino acid sequence of chitinase I (A L A T P T L N V S A S S G M) had no sequential identity to those of known chitinases.
    Download PDF (207K)
  • Tetsuo NAKANO, Koichiro MIYAKE, Hirofumi ENDO, Tohru DAIRI, Toru MIZUK ...
    2004 Volume 68 Issue 6 Pages 1345-1352
    Published: 2004
    Released: June 23, 2004
    JOURNALS FREE ACCESS
    For chlortetracycline biosynthesis in Streptomyces aureofaciens, the final reduction step is essential to give an antibiotic activity to its intermediate, which is catalyzed by tetracycline dehydrogenase with 7,8-dedimethyl-8-hydroxy-5-deazariboflavin (FO) as a cofactor. We identified and cloned the gene, which is essential for the biosynthesis of 6-demethyltetracycline and participates in the final step of its biosynthesis, from the genomic DNA of the 6-demethyltetracycline producer S. aureofaciens HP77. DNA sequence analysis revealed that the gene (tchA) had an open reading frame of 455 amino acids with an estimated molecular mass of 48.1 kDa. Southern hybridization analysis revealed that the tchA gene was located external to the chlortetracycline biosynthetic gene cluster in the genome. A conserved domain search of protein sequence databases indicated that TchA showed a similarity to FbiB, which is involved in the modification of FO in Mycobacterium bovis.
    Download PDF (204K)
Microbiology & Fermentation Technology Notes
feedback
Top