Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 69 , Issue 12
Showing 1-33 articles out of 33 articles from the selected issue
Review
  • Takeshi MIZUNO
    2005 Volume 69 Issue 12 Pages 2263-2276
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    One of the most fundamental and widespread mechanisms of signal perception/transduction in prokaryotes is generally referred to as the “two-component regulatory system (TCS).” The concept of TCS has already been introduced a decade ago from extensive studies on the model prokaryotic bacterium Escherichia coli. Results of recent studies on the model higher plant Arabidopsis thaliana have led us to learn a new scenario as to the versatility of TCS in eukaryotic species. In the plant, on the one hand, TCS are crucially involved in the signal transduction mechanism underlying the regulation of sophisticated plant development in response to hormones (e.g., cytokinin and ethylene). On the other hand, a unique TCS variant is essentially integrated into the plant clock function that generates circadian rhythms, and also tells us the time and season on this regularly spinning and revolving world. In this review, recent progress with regard to studies on TCS in higher plants will be discussed, focusing particularly on the model higher plant Arabidopsis thaliana.
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Analytical Chemistry Regular Paper
Organic Chemistry Regular Papers
Biochemistry & Molecular Biology Regular Papers
  • Masaaki TAZOE, Keiko ICHIKAWA, Tatsuo HOSHINO
    2005 Volume 69 Issue 12 Pages 2277-2284
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Here we report the purification and biochemical characterization of a pyridoxine 5′-phosphate phosphatase involved in the biosynthesis of pyridoxine in Sinorhizobium meliloti. The phosphatase was localized in the cytoplasm and purified to electrophoretic homogeneity by a combination of EDTA/lysozyme treatment and five chromatography steps. Gel-filtration chromatography with Sephacryl S-200 and SDS/PAGE demonstrated that the protein was a monomer with a molecular size of approximately 29 kDa. The protein required divalent metal ions for pyridoxine 5′-phosphate phosphatase activity, and specifically catalyzed the removal of Pi from pyridoxine and pyridoxal 5′-phosphates at physiological pH (about 7.5). It was inactive on pyridoxamine 5′-phosphate and other physiologically important phosphorylated compounds. The enzyme had the same Michaelis constant (Km) of 385 μM for pyridoxine and pyridoxal 5′-phosphates, but its specific constant [maximum velocity (Vmax)⁄Km] was nearly 2.5 times higher for the former than for the latter.
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  • Sheila NATHAN, Christoph RADER, Carlos F. BARBAS
    2005 Volume 69 Issue 12 Pages 2302-2311
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    The isolation of therapeutic and functional protease inhibitors in vitro via combinatorial chemistry and phage display technology has been described previously. Here we report the construction of a combinatorial mouse-human chimeric antibody fragment (Fab) antibody library targeted against the protease of the tropical pathogen, Burkholderia pseudomallei. The resulting library was biopanned against the protease, and selected clones were analyzed for their ability to function as protease inhibitors. Three families of Fabs were identified by restriction fingerprinting, all of which demonstrated high specificity towards the protease of B. pseudomallei. Purified Fabs also demonstrated the capacity to inhibit B. pseudomallei protease activity in vitro, and this inhibitory property was exclusive to the pathogenic protease. Thus these recombinant antibodies are candidates for immunotherapy and tools to aid in further elucidation of the mechanism of action of the B. pseudomallei protease.
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  • Atsushi ENOMOTO, Mayuko HASEGAWA, Shogo KOMINE
    2005 Volume 69 Issue 12 Pages 2312-2318
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Non-obese diabetic (NOD) mice spontaneously develop type 1 diabetes with a strong female predilection. Using co-culture systems with both female and male spleen cells, we found that spleen cells derived from male NOD mice suppress autoantigen (glutamic acid decarboxylase) induced production of interferon-γ of female cells in vitro. In addition, this suppression appeared to be mediated by a soluble factor(s) produced by male cells in response to the same antigen. Our experimental systems might be useful for further understanding sex differences in autoimmunity as well as in the basic immune response.
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  • Chia-Lin CHYAN, Tiger T. T. LEE, Chiung-Pin LIU, Yuan-Chang YANG, Jaso ...
    2005 Volume 69 Issue 12 Pages 2319-2325
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    A cDNA clone, SiMT encoding an Ec type of metallothionein (MT)-like protein, was isolated from maturing seeds of sesame (Sesamum indicum L.), and its deduced protein sequence shared 47–65% similarity to other known Ec type of MT-like proteins with three highly conserved cysteine-rich segments. The transcript of SiMT was exclusively accumulated in maturing seeds from two weeks after flowering to the end of seed maturation. The results of a southern blot analysis suggested that one SiMT and one SiMT-like gene were present in the sesame genome. Recombinant SiMT fused with glutathione-S-transferase (GST) was over-expressed in Escherichia coli, and purified to homogeneity by affinity chromatography. Recombinant SiMT released from GST was harvested after factor Xa cleavage. Migration of the recombinant SiMT during SDS–PAGE was accelerated when its binding metal ions were depleted by EDTA. The metal-binding capability of recombinant SiMT was measured by inductively-coupled plasma atomic emission spectrometry. Our results show that the recombinant SiMT could trap zinc or copper ions, but not manganese ions, with a stoichiometric ratio (metal ion/SiMT) of approximately 2.
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  • Kenji YAMAGISHI, Toshiyuki KIMURA, Masahiro SUZUKI, Ko-ji YAMAKI, Shig ...
    2005 Volume 69 Issue 12 Pages 2333-2342
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    This report describes the first cloning and overexpression experiments on genes encoding cAMP-dependent protein kinase catalytic subunits in homobasidiomycete Schizophyllum commune. We used a degenerate PCR approach to identify two novel genes (ScPKAC1 and ScPKAC2) that are very similar to the catalytic subunits in many eukaryotes. The morphological phenotypes of ScPKAC1 and ScPKAC2 overexpressing clones were compared with those of constitutively active ScGP-A overexpressing clones to determine whether ScPKAC1 and ScPKAC2 are located downstream of heterotrimeric G-protein alpha subunit ScGP-A. Overexpression of constitutively active ScGP-A increased intracellular cAMP levels and suppressed aerial mycelium formation. In contrast, overexpressing ScPKAC1 and ScPKAC2 did not affect the intracellular cAMP levels, though aerial mycelium formation was strongly suppressed. These observations suggest that ScPKAC1 and ScPKAC2 proteins are located downstream of the G-protein alpha subunit ScGP-A in the cAMP signaling pathway.
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  • Ileana Cornelia FARCASANU, Masaki MIZUNUMA, Fumitaka NISHIYAMA, Tokich ...
    2005 Volume 69 Issue 12 Pages 2343-2348
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Ni2+ toxicity can be alleviated in yeast cells by exogenous L-histidine, but not by its enantiomer, D-histidine, nor by other natural L-amino acids tested. We studied the effect of L-histidine upon the accumulation and intracellular distribution of Ni2+ and found that moderate L-histidine concentrations (less than or equal to those of Ni2+) increased cell tolerance without decreasing Ni2+ accumulation. Although excess L-histidine appeared to lower Ni2+ accumulation, the concomitant presence of Ni2+ and L-histidine in the growth medium stimulated each other’s uptake.
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  • Yasuhisa ASANO, Ken’ichirou TAMURA, Nobutaka DOI, Techawaree UEA ...
    2005 Volume 69 Issue 12 Pages 2349-2357
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    We established a simple HPLC method to determine the activity and stereochemistry of the chiral mandelonitrile synthesized from benzaldehyde and cyanide, and applied it to screen for hydroxynitrile lyase (HNL) activity of plant origin. A total of 163 species of plants among 74 families were examined for (R)- and (S)-HNL activities using the method. We discovered that homogenate of leaves of Baliospermum montanum shows (S)-HNL activity, while leaves and seeds from Passiflora edulis, and seeds from Eriobotrya japonica, Chaenomles sinensis, Sorbus aucuparia, Prunus mume, and Prunus persica show (R)-HNL activity. Partially purified (R)-HNLs from Passiflora edulis and Eriobotrya japonica acted not only on benzaldehyde but also on aliphatic ketone. The enantiomeric excess of (R)-methylpropylketone cyanohydrin synthesized from 2-pentanone using homogenate from leaves of Passiflora edulis was 87.0%, and that of (R)-mandelonitrile synthesized by homogenate from seeds of Eriobotrya japonica was 85.0%.
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  • Yoshiho NAGATA, Masako YAMASHITA, Hiroaki HONDA, Junko AKABANE, Koichi ...
    2005 Volume 69 Issue 12 Pages 2374-2380
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    A lectin named GFL was isolated from the fruiting body of the basidiomycete mushroom Grifola frondosa, which belongs to Aphyllophorales. The lectin had a molecular mass of 24 kDa on SDS–PAGE. The hemagglutinating activity of GFL was not inhibited by any monosaccharide, and inhibited only by porcine stomach mucin so far as tested. The occurrence of GFL was studied at three stages during fruiting body formation. The largest quantity of hemagglutinating activity was found in the fruiting body, and lesser amounts in the mycelial mat and the primordium. The 24-kDa band of GFL was found at all three stages, and the band-intensity corresponded to the level of activity in each sample. By cloning and sequencing the GFL-cDNA, the primary structure of this lectin was determined. GFL is composed of 181 amino acids, having no signal peptide. The amino acid sequence was found to be homologous to those of so-called jacalin-related plant lectins, suggesting that GFL is the first example of a jacalin-related lectin of fungal origin.
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  • Annalisa LAMBERTI, Olimpia LONGO, Pompea Del VECCHIO, Nicola ZAMBRANO, ...
    2005 Volume 69 Issue 12 Pages 2395-2400
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Rat brain Fe65 and its truncated forms corresponding to the combined PTB1 and PTB2 domains, as well as to the isolated PTB2 domain, were expressed in Escherichia coli and purified from inclusion bodies by affinity chromatography. The recombinant proteins were refolded and judged functionally active by their ability to interact with native APP. Limited proteolysis of recombinant Fe65 and PTB1–2 with trypsin, chymotrypsin and V8 proteases showed that the most sensitive proteoltytic sites were positioned at the level of the interdomain regions comprised between WW/PTB1 and PTB1/PTB2. Secondary structure of the recombinant proteins, evaluated by CD spectroscopy, showed a different degree of unordered structures, the PTB2 domain being the higher organised region. In addition, intrinsic fluorescence measurements of PTB2, indicated that a conformational transition of the protein can be induced by denaturating agents such as GuHCl. These data provide first evidences on the secondary structural levels of Fe65.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Cenk KIG, Sezai TURKEL, Güler TEMIZKAN
    2005 Volume 69 Issue 12 Pages 2475-2478
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    We have isolated 14 different Schizosaccharomyces pombe mutants that synthesize invertase enzyme constitutively. Analyses of invertase activities revealed that the degrees of resistance to glucose repression were not similar among different complementation groups. One of the complementation groups appeared to be associated with functional and/or regulatory defects in hexose transport. Another complementation group appeared to be specific for the regulation of the inv1 gene alone, implying that these mutations might be associated with different genes acting on the glucose sensing and signaling pathway. In addition, we found that the wild-type level glucose uptake is essential for the full-level repression of inv1 expression.
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Food & Nutrition Science Regular Papers
  • Kouhei NAKAJIMA, Norimitsu TAMURA, Kazuo KOBAYASHI-HATTORI, Tadashi YO ...
    2005 Volume 69 Issue 12 Pages 2294-2301
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    The preventive effects of glycomacropeptide (GMP) against intestinal infection were investigated, and conjugates of GMP with xylooligosaccharide (XOS) and carboxymethyldextran (CMD) were prepared by the Maillard reaction to enhance the effect of GMP. The binding ability of GMP to intestinal pathogenic bacteria was evaluated by a binding assay with biotinylated bacteria. GMP showed the ability to bind to Salmonella enteritidis and enterohemorrhagic Escherichia coli O157:H7 (EHEC O157). This binding ability was decreased by a sialidase treatment and completely eliminated by periodate oxidation. These results indicate that such carbohydrate moieties as sialic acid in GMP are involved in binding to S. enteritidis and EHEC O157. The preventive effect of GMP on the adhesion of pathogenic bacteria to Caco-2 cells was also investigated. GMP showed an inhibitory effect on the adhesion of EHEC O157 in a dose-dependent manner, although it was not a potent inhibitor of the adhesion of Salmonella infection. However, in the case of Salmonella infection, GMP–XOS and GMP–CMD significantly suppressed IL-8 production which was the index of infection. Our results indicate GMP to be a promising agent for preventing intestinal infection.
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  • Mineka YOSHIMURA, Yuko WATANABE, Kouichi KASAI, Jun YAMAKOSHI, Takuro ...
    2005 Volume 69 Issue 12 Pages 2368-2373
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    A pomegranate extract (PE) from the rind containing 90% ellagic acid was tested for its skin-whitening effect. PE showed inhibitory activity against mushroom tyrosinase in vitro, and the inhibition by the extract was comparable to that of arbutin, which is a known whitening agent. PE, when administered orally, also inhibited UV-induced skin pigmentation on the back of brownish guinea pigs. The intensity of the skin-whitening effect was similar between guinea pigs fed with PE and those fed with L-ascorbic acid. PE reduced the number of DOPA-positive melanocytes in the epidermis of UV-irradiated guinea pigs, but L-ascorbic acid did not. These results suggest that the skin-whitening effect of PE was probably due to inhibition of the proliferation of melanocytes and melanin synthesis by tyrosinase in melanocytes. PE, when taken orally, may be used as an effective whitening agent for the skin.
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  • Asuka AKAHOSHI, Kazunori KOBA, Rie ENMOTO, Kazuko NISHIMURA, Yukiko HO ...
    2005 Volume 69 Issue 12 Pages 2409-2415
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    The interaction of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) was studied in male rats fed diets containing casein (CAS) or soy protein (SOY) as a protein source with low fat (LF, 6.0% soybean oil) or high fat (HF, 13.0% soybean oil) combinations for 4 weeks. CLA was added at the 1.0% level to all diets. The weight of perirenal adipose tissue tended to be lower in the SOY groups than in the corresponding CAS groups, and the difference between the LF diets was significant. The weight of epididymal adipose tissue showed a similar but insignificant trend. The weight of brown adipose tissue was heaviest on the SOY-HF diet and lowest on two CAS diets, the SOY-LF diet being intermediate. The concentration of serum leptin was lowest on the SOY-LF diet and was significantly lower than that of the corresponding CAS group, but this difference disappeared when the dietary fat level increased. The serum cholesterol-lowering activity of SOY in relation to CAS was reproduced even when CLA was given. Thus the body fat-reducing activity of CLA was most marked when rats were fed the SOY-LF diet. Although the CAS-HF diet increased body fat deposition, the magnitude of the reduction by lowering dietary fat level was more marked than in the case of SOY. These results indicate a complicated interaction of dietary manipulations with the body fat-reducing effect of CLA, but the combination of CLA with the SOY-LF diet appears to be an appropriate approach.
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Food & Nutrition Science Notes
Food & Nutrition Science Communications
Microbiology & Fermentation Technology Regular Paper
  • Emiko KITAGAWA, Kuniko AKAMA, Hitoshi IWAHASHI
    2005 Volume 69 Issue 12 Pages 2285-2293
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    It is well documented that iodine kills microorganisms with a broad spectrum, but a systematic study of its mechanism of action has not yet been reported. Here we found the action of iodine on gene expression level, using the yeast Saccharomyces cerevisiae with a DNA microarray. It was found that, like antimicrobial activity, iodine causes an immediate and dose-dependent (0.5 mM, 0.75 mM and 1 mM) transcriptional alteration in yeast cells. The effects of iodine continued after the first immediate response. Genes for c-compound and carbohydrate metabolism, for energy, and for cell rescue were continuously up-regulated. On the other hand, genes related to protein fate were induced especially at 0.5 h. The gene expression profile at 0.5 h was significantly different from that of a longer iodine exposed condition. The main reaction at 0.5 h after iodine addition might be due to oxidative toxicity, and the profile at 0.5 h was similar to that of an agricultural bactericide.
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  • San-Chin TSAI, Li-Duan TSAI, Yaw-Kuen LI
    2005 Volume 69 Issue 12 Pages 2358-2367
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    An isolated yeast strain was grown aerobically on phenol as a sole carbon source up to 24 mM; the rate of degradation of phenol at 30 °C was greater than other microorganisms at the comparable phenol concentrations. This microorganism was further identified and is designated Candida albicans TL3. The catabolic activity of C. albicans TL3 for degradation of phenol was evaluated with the Ks and Vmax values of 1.7±0.1 mM and 0.66±0.02 μmol/min/mg of protein, respectively. With application of enzymatic, chromatographic and mass-spectrometric analyses, we confirmed that catechol and cis,cis-muconic acid were produced during the biodegradation of phenol performed by C. albicans TL3, indicating the occurrence of an ortho-fission pathway. The maximum activity of phenol hydroxylase and catechol-1,2-dioxygenase were induced when this strain grew in phenol culture media at 22 mM and 10 mM, respectively. In addition to phenol, C. albicans TL3 was effective in degrading formaldehyde, which is another major pollutant in waste water from a factory producing phenolic resin. The promising result from the bio-treatment of such factory effluent makes Candida albicans TL3 be a potentially useful strain for industrial application.
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  • Megumi SHOBAYASHI, Shin-ichiro MITSUEDA, Mariko AGO, Tsutomu FUJII, Ka ...
    2005 Volume 69 Issue 12 Pages 2381-2388
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Ergosterol is an essential component of yeast cells that maintains the integrity of the membrane. It was investigated as an important factor in the ethanol tolerance of yeast cells. We investigated the effects of brewing conditions on the ergosterol contents of S. cerevisiae K-9, sake yeast, several kinds of Saccharomyces cerevisiae that produce more than 20% ethanol, and X2180-1A, laboratory yeast. K-9 had a higher total ergosterol contents under all the conditions we examined than X2180-1A. Ethanol and hypoxia were found to have negative and synergistic effects on the total ergosterol contents of both strains, and significantly reduced the free ergosterol contents of X2180-1A but only slightly reduced those of K-9. The maintenance of free ergosterol contents under brewing conditions might be an important character of sake yeast strains. DNA microarray analysis also showed higher expression of ergosterol biosynthesis genes in K-9 than in X2180-1A.
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  • Ehsan ALI, Rie ARAKI, Guangshan ZHAO, Makiko SAKKA, Shuichi KARITA, Te ...
    2005 Volume 69 Issue 12 Pages 2389-2394
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    Clostridium josui xylanase Xyn10A is a modular enzyme comprising two family-22 carbohydrate-binding modules (CBMs), a family-10 catalytic module (CM), a family-9 CBM, and two S-layer homologous modules, consecutively from the N-terminus. To study the functions of the family-22 CBMs, truncated derivatives of Xyn10A were constructed: a recombinant CM polypeptide (rCM), a family-22 CBM polypeptide (rCBM), and a polypeptide composed of the family-22 CBMs and CM (rCBM-CM). Recombinant proteins were characterized by enzyme and binding assays. rCBM-CM showed the highest activity toward xylan and weak activity toward some polysaccharides such as barley β-glucan and carboxymethyl-cellulose. Although rCBM showed an affinity for insoluble and soluble xylan as well as barley β-glucan and Avicel in qualitative binding assays, removal of the CBMs negligibly affected the catalytic activity and thermostability of the CM.
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  • Mitsutoshi KUBOTA, Miho NODATE, Mina YASUMOTO-HIROSE, Taku UCHIYAMA, O ...
    2005 Volume 69 Issue 12 Pages 2421-2430
    Published: 2005
    Released: December 23, 2005
    JOURNALS FREE ACCESS
    The cytochrome P450 CYP153 family is thought to mediate the terminal hydroxylation reactions of n-alkanes. We isolated 16 new P450 CYP153A genes (central region) from various environments such as petroleum-contaminated soil and groundwater, as well as one from the n-alkane-degrading bacterium Alcanivorax borkumensis SK2 (designated P450balk). The sequences of the new P450 genes were extended by PCR to generate full-length chimeric P450 genes, using the N- and C-terminal domains of P450balk. A differential CO-reduced P450 spectral analysis indicated that 8 P450 genes among the 16 chimeric genes were expressed in Escherichia coli to generate a soluble and functional enzyme. The several functional chimeric P450s and P450balk were further fused to the reductase domain of the self-sufficient P450 monooxygenase (P450RhF) at the C-terminus. E. coli cells expressing these self-sufficient P450 chimeric genes converted n-alkanes, cyclohexane, 1-octene, n-butylbenzene, and 4-phenyl-1-butene into 1-alkanols, cyclohexanol, 1,2-epoxyoctane, 1-phenyl-4-butanol, and 2-phenethyl-oxirane, respectively.
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Microbiology & Fermentation Technology Notes
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