Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 72 , Issue 2
Showing 1-50 articles out of 53 articles from the selected issue
Award Review
  • Kousaku MURATA, Shigeyuki KAWAI, Bunzo MIKAMI, Wataru HASHIMOTO
    2008 Volume 72 Issue 2 Pages 265-277
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Sphingomonas species A1 is a newly identified pit-forming bacterium that directly incorporates a macromolecule (alginate) into its cytoplasm through a pit-dependent transport system, which we termed a superchannel. A pit is a novel, high-dimensional organ acquired through the fluidity and reconstitution of cell surface molecules, including flagellin, and through cooperation with the transport machinery in the cells, which confers upon bacterial cells a more efficient way to secure and assimilate macromolecules. The analysis of the superchannel changes general ideas regarding the fluidity and function of the cell surface, evolution and origin of cell-surface organs, including flagella, transport, and assimilation systems of macromolecules, and the divergence and energetics of metabolism.
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Organic Chemistry Regular Papers
  • Young Heui KIM, Chan Bok CHUNG, Jin Guk KIM, Kang Il KO, Sun Hee PARK, ...
    2008 Volume 72 Issue 2 Pages 303-311
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    In order to investigate the potential of a Sanguisorba officinalis root extract as an active ingredient for wrinkle-care cosmetics, we measured its free radical scavenging activity, elastase inhibitory activity, expression of MMP-1 (matrix metalloprotease-1) in vitro, and type I collagen synthesis in normal human fibroblast cells. To isolate the main components from the S. officinalis root extract, we purified the extract by solvent fractionation, column chromatography, and recrystallization. The active component was identified as ziyuglycoside I by a spectroscopic analysis. Ziyuglycoside I increased the expression of type I collagen in a dose-dependent manner (by up to 71.3% at 50 μM). A clinical study of a formulation containing ziyuglycoside I, which involved visual evaluation and image analysis, showed a significantly different effect (p<0.05) of the test formulation from that of the placebo. This result suggests that ziyuglycoside I isolated from S. officinalis root extract could be used as an active ingredient for cosmetics.
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  • Norio MUTO, Tatsuru TOMOKUNI, Mari HARAMOTO, Hideki TATEMOTO, Tsutomu ...
    2008 Volume 72 Issue 2 Pages 477-484
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    A chloroform extract of the leaves of Juniperas taxifolia exhibited a marked antiproliferative effect on human promyelocytic leukemia HL-60 cells at a concentration of 2.5 μg/ml. Deoxypodophyllotoxin (4) was identified in the extract as an outstanding antiproliferative compound, and five diterpenes (13, 5, and 6) were isolated as known compounds with weak or no cytotoxicity. These compounds were examined for their respective apoptosis- and differentiation-inducing activities toward HL-60 cells by DNA fragmentation and NBT-reducing assays, respectively. Among them, 7α-hydroxysandaracopimaric acid (6) was found to have a potent differentiation-inducing activity in a dose-dependent manner at 0.125–2 μg/ml (0.39–6.29 μM), together with apoptosis-inducing activity at concentrations of more than 2.5 μg/ml (7.86 μM). Deoxypodophyllotoxin (4) that exerted cytotoxic and apoptosis-inducing activities at 2 ng/ml (5 nM) did not induce differentiation at the same concentration, and the other diterpenes (13 and 5) showed no effect on cell differentiation, even at 5 μg/ml. It was thus demonstrated for the first time that 7α-hydroxysandaracopimaric acid was an effective differentiation-inducing compound toward HL-60 cells.
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  • Yutaka HAYASHI, Tomonobu TOYOMASU, Yuko HIROSE, Yu ONODERA, Wataru MIT ...
    2008 Volume 72 Issue 2 Pages 523-530
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The rice genome contains two ent-copalyl diphosphate synthase genes: OsCPS1 acts in gibberellin (phytohormone) biosynthesis, and OsCPS2/OsCyc2 acts in the synthesis of oryzalexins A-F and phytocassanes A-E (phytoalexins). We characterized the enzymatic properties of recombinant OsCPS2/OsCyc2 fused with a tag-protein at the N-terminus, and compared them to those of OsCPS1. Several enzymatic properties of OsCPS2/OsCyc2, including the optimal pH, optimal temperature, divalent cation requirement, and kinetic values for the geranylgeranyl diphosphate (GGDP) substrate, were almost the same as those of OsCPS1. However, OsCPS2/OsCyc2 activity was not inhibited by 50–60 μM GGDP substrate, by which the OsCPS1 activity was inhibited. Furthermore, the OsCPS1 activity exhibited approximately 70% inhibition by 100 μM Amo-1618 (a gibberellin biosynthetic inhibitor), whereas the OsCPS2/OsCyc2 activity exhibited approximately 10% inhibition. These results indicate that the properties of OsCPS2/OsCyc2 were partially different from those of OsCPS1, although OsCPS2/OsCyc2 catalyzes the same reaction step as OsCPS1.
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  • Tomonobu TOYOMASU, Takuma KAGAHARA, Kazunori OKADA, Jinichiro KOGA, Mo ...
    2008 Volume 72 Issue 2 Pages 562-567
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Rice (Oryza sativa L.) produces a variety of diterpene phytoalexins, such as momilactones, phytocassanes, and oryzalexins. Momilactone B was previously identified as an allelopathic substance exuded from the roots of rice. We identified in this present study momilactone A and phytocassanes A–E in extracts of, and exudates from, the roots of rice seedlings. The concentration of each compound was of the same order of magnitude as that of momilactone B. Expression analyses of the diterpene cyclase genes responsible for the biosynthesis of momilactones and phytocassanes suggest that these phytoalexins found in roots are primarily biosynthesized in those roots. None of phytocassanes B–E exhibited allelopathic activity against dicot seedling growth, whereas momilactone A showed much weaker allelopathic activity than momilactone B. The exudation of diterpene phytoalexins from the roots might be part of a system for defense against root-infecting pathogens.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Yoshikazu ENDO, Misako YOKOYAMA, Munenori MORIMOTO, Kengo SHIRAI, Go C ...
    2008 Volume 72 Issue 2 Pages 312-320
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Expression of the eglA gene, encoding for a major endoglucanse EG A in Aspergillus nidulans, is induced by cellulose and cellobiose, but not by xylose. This suggests that induction is independent of XlnR, a transcriptional activator of xylanolytic and cellulolytic genes in Aspergillus.
    Mutational analysis of the eglA promoter was performed to identify the novel cis-element responsible for XlnR-independent induction. The region spanning −153 to −138 (CCGTACCTTTTTAGGA), designated CeRE(Cellulose Responsive Element), was found to be the upstream activating element essential to inductive expression of the eglA gene.
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  • Satoru YASUDA, Satoko HASUI, Masaki KOBAYASHI, Shirou ITAGAKI, Takeshi ...
    2008 Volume 72 Issue 2 Pages 329-334
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The aim of this study was to elucidate the mechanism of folate transport in the placenta. A study of folate was carried out to determine which carriers transport folates in the human choriocarcinoma cell line BeWo, a model cell line for the placenta. We investigated the effects of buffer pH and various compounds on folate uptake. In the first part of the study, the expression levels of the mRNA of the folate receptor α (FRα), the reduced folate carrier (RFC), and heme carrier protein 1 (HCP1) were determined in BeWo cells by RT-PCR analysis. Folate uptake into BeWo cells was greater under an acidic buffer condition than under a neutral one. Structure analogs of folates inhibited folate uptake under all buffer pH conditions, but anion drugs (e.g., pravastatin) inhibited folate uptake only under an acidic buffer condition. Although thiamine pyrophosphate (TPP), a substrate of RFC, had no effect on folate uptake, hemin (a weak inhibitor of folate uptake via HCP1) decreased folate uptake to about 80% of the control level under an acidic buffer condition. Furthermore, kinetic analysis showed that hemin inhibited the low-affinity phase of folate uptake under an acidic buffer condition. We conclude that pH-dependent folate uptake in BeWo cells is mediated by at least two carriers. RFC is not involved in folate uptake, but FRα (high affinity phase) and HCP1 (low affinity phase) transport folate in BeWo cells.
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  • Katjana DASKALOW, Prisca BOISGUERIN, Burkhard JANDRIG, Rudolf VOLKMER, ...
    2008 Volume 72 Issue 2 Pages 346-351
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Monoclonal antibodies against S-tagged fusion proteins expressed in pET vectors were generated and further characterized. Most pET vectors contain a 15-meric S-tag as a fusion tag for the detection of recombinant proteins. Two antibodies, G18BA3 and G18BE8, recognized this S-tag in enzyme immunoassay and Western blot. Their epitopes were mapped using peptide array technology and were confirmed to be AAKFERQHMDSPD. This corresponds to the C-terminal region of the S-tag plus additional amino acids P and D, which are also present in most available pET vectors. Amino acid substitution analysis revealed several essential residues for binding. The binding motif was therefore FExxHxDxxD for G18BA3 and AxxFExxH for G18BE8. Since some commercially available protein standards are expressed in pET vectors, G18BA3 and G18BE8 were also found to detect the ladder bands of a molecular weight marker on immunoblot analysis. Both antibodies should be highly useful for the simultaneous detection of recombinant pET vector-expressed fusion proteins and protein molecular weight standards in Western blotting, especially when chemoluminescent detection systems are used.
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  • Qin YAN, Wei ZHOU, Xingwei LI, Meiqing FENG, Pei ZHOU
    2008 Volume 72 Issue 2 Pages 352-359
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The purification method for a novel ginsenoside-hydrolyzing β-glucosidase from Paecilomyces Bainier sp. 229 was successfully simplified by the application of microcrystalline cellulose (MCC) as a novel chromatographic matrix. Only two chromatographic steps, Q-Sepharose FF and MCC column in sequence, were required to purify the enzyme to apparent homogeneity. The purified enzyme, with a native molecular weight estimated to be 305 KDa, was composed of three identical subunits of approximately 102 KDa each. The optimal enzyme activity was observed at pH 3.5 at 55 °C. It was stable within pH 3–7 and at temperatures lower than 50 °C. The optimal substrate for the enzyme was p-nitrophenyl-β-D-glucoside, followed by ginsenoside Rd, gentiobiose, and ginsenoside Rb1. It converted ginsenoside Rb1 to ginsenoside Rg3 specifically and efficiently. The hydrolyzing pathway of ginsenoside Rb1 by the enzyme was Rb1→Rd→Rg3. The specific activities against ginsenoside Rb1 and Rd were 56.7 μmol/min/mg and 129.4 μmol/min/mg respectively.
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  • Takekazu OKUMURA, Fumiko NAGAI, Shuta YAMAMOTO, Toshikazu HASHIMOTO, M ...
    2008 Volume 72 Issue 2 Pages 360-367
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    This report describes a new immunological method for the detection and quantification of Nitrospira populations using the reverse passive latex agglutination (RPLA). The numbers of the genus Nitrospira have been quantified only by molecular biological techniques such as FISH and quantitative PCR to date. Using high-density latex particles and a specific polyclonal antibody, Nitrospira populations in the wastewater treatment process were quantified in the shortest 4 h of incubation. The minimum detectable number of Nitrospira cells was 7.0×105 (log10 5.85) cells/ml. It is thought that the RPLA method can quantify Nitrospira populations more simply, economically, and speedily than molecular biological techniques or the culture method, because this procedure has a simple protocol and does not require the use of specialized equipment, expensive reagents, or technical skill. Therefore it is applicable for use in the everyday control and maintenance of water quality in wastewater treatment facilities where equipment is not sufficient or in the field.
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  • Hiromichi SAINO, Masaharu MIZUTANI, Jun HIRATAKE, Kanzo SAKATA
    2008 Volume 72 Issue 2 Pages 376-383
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    β-Primeverosidase (PD) is a family 1 glycosidase catalyzing the hydrolysis of β-primeverosides (6-O-β-D-xylopyranosyl-β-D-glucopyranosides) to release a disaccharide primeverose. To investigate how PD recognizes the disaccharide moiety of β-primeverosides, the recombinant PD was expressed by a baculovirus-insect cell system. The recombinant PD was secreted from High Five cells and was properly modified with N-glycosylation and correct cleavage at the N-terminal signal peptide. The recombinant PD exhibited high substrate specificity to β-primeverosides in terms of the glycone moiety, consistently with the substrate specificity of native PD from Camellia sinensis. Next, β-glycosylamidines were synthesized as substrate analog inhibitors. β-Primeverosylamidine strongly inhibited PD activity, but β-glucosylamidine did not. Hence β-primeverosylamidine is an ideal chemical tool for probing disaccharide recognition in the active site of PD. An affinity adsorbent for PD was prepared using β-primeverosylamidine as a ligand. Affinity chromatography gave large amounts of PD with high purity, permitting crystallographic study.
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  • Kojiro TAKANASHI, Nobukazu SHITAN, Akifumi SUGIYAMA, Yoshihisa KAMIMOT ...
    2008 Volume 72 Issue 2 Pages 398-405
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Many plant secondary metabolites show strong biological activities and are potentially also toxic to plants, while plants producing such active compounds are usually insensitive to their own metabolites, suggesting that they have species-specific detoxification mechanisms. In order to clarify the detoxification mechanism of alkaloids, we used cultured cells of Coptis japonica, which are capable of producing a yellow benzylisoquinoline alkaloid, berberine, and accumulate it in the vacuole. Unlike other plant cells that do not produce berberine, C. japonica shows strong tolerance to this alkaloid. We established a fission yeast strain that was sensitive to berberine and performed functional screening using a C. japonica cDNA library. One cDNA clone, which conferred clear berberine tolerance, encoded galactinol synthase (CjGolS). The possible role of CjGolS in berberine tolerance is discussed.
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  • Muneaki HIDAKA, Masashi NAGATA, Yohei KAWANO, Hiroshi SEKIYA, Hirofumi ...
    2008 Volume 72 Issue 2 Pages 406-411
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    There is limited information on the effect of fruits on human cytochrome P450 (CYP) 2C9 activity. The objective of this study was to determine the effect of fruit juice on CYP2C9-mediated drug metabolism. Nine citrus fruits and eight tropical fruits were chosen. We investigated effects of the fruits on diclofenac 4′-hydroxylation and tolbutamide hydroxylation by human liver microsomes. Among the fruits, pineapple juice showed potent inhibition of CYP2C9 activity. The addition of 25 μl (5.0% v/v) of pineapple juice resulted in almost complete inhibition. Next we examined the inhibitory effect of bromelain, a cysteine protease in pineapple. Bromelain also strongly inhibited CYP2C9 activity. In addition, E-64, a cysteine protease inhibitor, almost entirely blocked inhibition by pineapple juice and bromelain. Thus we found that pineapple juice was a potent inhibitor of CYP2C9, and that the inhibitory effect might be due to the bromelain contained in pineapple.
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  • Asako SUZUKI, Kyoko KANAMARU, Nobuhiro AZUMA, Masashi KATO, Tetsuo KOB ...
    2008 Volume 72 Issue 2 Pages 428-434
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    His-Asp phosphorelays are signal transduction mechanisms widely found in both prokaryotes and eukaryotes. The phosphorelay comprises three types of signal transducers: a sensor with histidine kinase (HK), a response regulator containing a phospho-accepting receiver (RR), and a histidine-containing phosphotransmitter (HPt). In this study, we examined HK expression using a green fluorescent protein (GFP) reporter driven by HK promoters in Aspergillus nidulans. All the transformants showed fluorescence derived from GFP in a submerged culture, although some of them were very weak, indicating that all the promoters were active. As judged by the fluorescence of transformants grown on a culture plate on which sexual development was induced, promoters of fphA, hk-8-2, and hk-8-5 preferentially functioned in conidial heads, the promoter of phkA preferentially functioned in cleistothecia, and the promoters of tcsB and nikA function in both conidial heads and cleistothecia. These results indicate that at least some HKs of A. nidulans showed temporally and spatially different expression during the cell cycle.
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  • Masataka KAJIKAWA, Keisuke MATSUI, Misa OCHIAI, Yoshikazu TANAKA, Yoic ...
    2008 Volume 72 Issue 2 Pages 435-444
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The liverwort Marchantia polymorpha L. synthesizes arachidonic (ARA) and eicosapentaenoic acids (EPA) from linoleic and α-linolenic acids respectively by a series of reactions catalyzed by Δ6-desaturase, Δ6-elongase, and Δ5-desaturase. Overexpression of the M. polymorpha genes encoding these enzymes in transgenic M. polymorpha plants resulted in 3- and 2-fold accumulation of ARA and EPA respectively, as compared to those in the wild type. When these three genes were introduced and co-expressed in tobacco plants, in which long-chain polyunsaturated fatty acids (LCPUFAs) are not native cellular components, ARA and EPA represented up to 15.5% and 4.9% respectively of the total fatty acid in the leaves. Similarly in soybean, C20-LCPUFAs represented up to 19.5% of the total fatty acids in the seeds. These results suggest that M. polymorpha can provide genes crucial to the production of C20-LCPUFAs in transgenic plants.
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  • Shaofu LIAO, Phuntip POONPAIROJ, Kyong-Cheol KO, Yumiko TAKATUSKA, Yos ...
    2008 Volume 72 Issue 2 Pages 445-455
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Selenomonas ruminantium synthesizes cadaverine and putrescine from L-lysine and L-ornithine as the essential constituents of its peptidoglycan by a constitutive lysine/ornithine decarboxylase (LDC/ODC). S. ruminantium grew normally in the presence of the specific inhibitor for LDC/ODC, DL-α-difluoromethylornithine, when arginine was supplied in the medium. In this study, we discovered the presence of arginine decarboxylase (ADC), the key enzyme in agmatine pathway for putrescine synthesis, in S. ruminantium. We purified and characterized ADC and cloned its gene (adc) from S. ruminantium chromosomal DNA. ADC showed more than 60% identity with those of LDC/ODC/ADCs from Gram-positive bacteria, but no similarity to that from Gram-negative bacteria. In this study, we also cloned the aguA and aguB genes, encoding agmatine deiminase (AguA) and N-carbamoyl-putrescine amidohydrolase (AguB), both of which are involved in conversion from agmatine into putrescine. AguA and AguB were expressed in S. ruminantium. Hence, we concluded that S. ruminantium has both ornithine and agmatine pathways for the synthesis of putrescine.
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  • Tyler J. AVIS, Raphaël ANGUENOT, Bertrand NEVEU, Sébastien ...
    2008 Volume 72 Issue 2 Pages 456-462
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The basidiomycetous fungus Pseudozyma flocculosa represents a promising new host for the expression of complex recombinant proteins. Two novel heterologous promoter sequences, the Ustilago maydis glyceraldehyde-3-phosphate dehydrogenase (GPD) and Pseudozyma tsukubaensis α-glucosidase promoters, were tested for their ability to provide expression in P. flocculosa. In liquid medium, these two promoters produced lower levels of intracellular green fluorescent protein (GFP) as compared to the U. maydis hsp70 promoter. However, GPD and α-glucosidase sequences behaved as constitutive promoters whereas the hsp70 promoter appeared to be morphology-dependent. When using the hsp70 promoter, the expression of GFP increased proportionally to the concentration of hygromycin in the culture medium, indicating possible induction of the promoter by the antibiotic. Optimal solid-state culture conditions were designed for high throughput screening of hygromycin-resistant transformants with the hsp70 promoter in P. flocculosa.
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  • Takuya SAKURAI, Hiroshi NISHIOKA, Hajime FUJII, Norihiko NAKANO, Takak ...
    2008 Volume 72 Issue 2 Pages 463-476
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    In this study we investigated the antioxidative effects of Oligonol (Amino Up Chemical Co., Ltd., Sapporo, Japan), a new polyphenol, in adipocytes. The levels of reactive oxygen species (ROS) and the expression of adipokine genes decreased in HW mouse white adipocytes upon treatment with Oligonol as compared to control cells. The transcriptional activity of nuclear factor-kappaB (NF-κB) and the activation of extracellular signal-regulated kinase (ERK) 1/2 were also down-regulated by Oligonol. In addition, when C57BL/6J mice were fed a high fat diet (HFD) for 5 weeks, the levels of epididymal white adipose tissue (WAT) mass and lipid peroxidation in WAT both increased, but Oligonol intake clearly inhibited such HFD-induced increases. Furthermore, dysregulated expression of genes for adipokines in WAT of mice fed solely a HFD was attenuated by Oligonol intake. These results suggest that Oligonol has antioxidative effects and that it attenuates HFD-induced dysregulated expression of genes for adipokines in adipocytes.
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  • Yoshinobu KIMURA, Misao KUROKI, Megumi MAEDA, Mitsuhiro OKANO, Minehik ...
    2008 Volume 72 Issue 2 Pages 485-491
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    A Japanese cypress (Chamaecyparis obtusa) pollen allergen, Cha o 1, is one of the major allergens that cause allergic pollinosis in Japan. Although it has been found that Cha o 1 is glycosylated and that the amino acid sequence is highly homologous with that of Japanese cedar pollen allergen (Cry j 1), the structure of N-glycans linked to Cha o 1 remains to be determined. In this study, therefore, we analyzed the structures of the N-glycans of Cha o1. The N-glycans were liberated by hydrazinolysis from purified Cha o 1, and the resulting sugar chains were N-acetylated and pyridylaminated. The structures of pyridylaminated N-glycans were analyzed by a combination of exoglycosidase digestion, two dimensional (2D-) sugar chain mapping, and electrospray ionization mass spectrometry analysis. Structural analysis indicated that the major N-glycan structure of Cha o1 is GlcNAc2Man3Xyl1Fuc1GlcNAc2 (89%), and that high-mannose type structures (Man9GlcNAc2, Man7GlcNAc2) occur as minor components (11%).
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  • Anna C. N. CHUA, Eric S. L. HSIAO, Yuan-Chang YANG, Li-Jen LIN, Wing-M ...
    2008 Volume 72 Issue 2 Pages 506-513
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Seed storage proteins of plants commonly comprise several groups of multiple isoforms encoded by gene families. From about 300 expressed sequence tag (EST) clones in maturing jelly fig (Ficus awkeotsang Makino) achenes, gene families encoding precursor polypeptides of two storage protein classes, including six 11S globulin isoforms and two 2S albumin isoforms, were identified. Complete sequences encoding the precursor polypeptides of these eight storage proteins were obtained by sequencing the pertinent EST clones that contained full-length cDNA fragments. Matrix-assisted laser desorption/ionization mass spectrometry analysis confirmed the presence of these storage protein isoforms in the extract of jelly fig achenes resolved in SDS–PAGE. The amino acid compositions of the deduced storage proteins indicated that achene proteins in jelly fig are nutritive, for both isoforms of 2S albumin are sulfur-rich, and one of them is also rich in tryptophan.
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  • Yoshinobu KIMURA, Takao WATANABE, Mariko KIMURA, Megumi MAEDA, Yoshiyu ...
    2008 Volume 72 Issue 2 Pages 514-522
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    In this report, we describe that a salt adaptation of plant cells induces glycoform changes in N-glycoproteins. Intracellular and cell-wall glycopeptides were prepared from glycoproteins expressed in wild-type BY2 cells and salt-adapted cells. N-Glycans were liberated from those glycopeptides by hydrazinolysis, and the released oligosaccharides were N-acetylated and pyridylaminated. The structures of pyridylaminated (PA-) N-glycans were analyzed by a combination of two-dimensional sugar-chain mapping, MS analysis, and exoglycosidase digestion. In both wild-type cells and salt-adapted cells, the plant complex type structure was predominant among N-glycans expressed on glycoproteins, but we found that the Man2Xyl1Fuc1GlcNAc2 structure was significantly expressed on intracellular and cell-wall glycoproteins of the salt-adapted cells. Furthermore, enhancement of the specific activities of α-mannosidase and β-N-acetylglucosaminidase was observed in the salt-adapted BY2 cells, suggesting that the glycoform changes are due to changes in glycosidase activities.
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  • Kenji HATTORI, Noriko MOTOHASHI, Izumi KOBAYASHI, Takeshi TOHYA, Mai O ...
    2008 Volume 72 Issue 2 Pages 540-547
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    We have identified four cytosolic sulfotransferase (SULT) homologs in the genome database of Drosophila melanogaster, and have designated these genes dmST1-4. Each of these four isozymes was subsequently classified into a different and novel gene family, as determined by the low amino acid sequence homology (less than 40%) between them, and also toward their vertebrate homologs. The transcripts for these four SULT homologs were detectable at all developmental stages in D. melanogaster. In addition, three of these isozymes, the exception being dmST2, were successfully expressed and purified in Escherichia coli. These recombinant dmST1, 3, and 4 products showed high sulfating activity toward phenolic compounds such as vanillin and 4-nitrophenol, but showed no activity toward typical endogenous substrates such as tyramine and serotonin. DmST4 and dmST3 showed the lowest and highest Km values for 3′-phosphoadenosine-5′-phosphosulfate (PAPS) respectively. DmST4 also showed low but not negligible activity toward 20-hydroxyecdysone.
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  • Akira HOSOMI, Yu-ya KAWANISHI, Naotaka TANAKA, Kaoru TAKEGAWA
    2008 Volume 72 Issue 2 Pages 548-556
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    PhoX homology (PX) domain-containing proteins play critical roles in vesicular trafficking, protein sorting, and lipid modification in eukaryotic cells. Several proteins with PX domains contain an associated domain termed PXA (PX-associated). Although PXA domain-containing proteins are required for some important cellular processes, the function of the PXA domain is unknown. We identified three PXA domain-containing proteins in Schizosaccharomyces pombe. S. pombe Pxa1p (SPAC5D6.07c) contained only the PXA domain, not the PX domain. To elucidate the role of the PXA domain in eukaryotic cells, we constructed and characterized a disruption mutant, pxa1. The pxa1 disruptant contained enlarged vacuoles and exhibited mislocalization of vacuolar carboxypeptidase Y (CPY). The conversion rate from pro- to mature-CPY was greatly impaired in pxa1 cells, and fluorescence microscopy indicated that a sorting receptor for CPY, Vps10p, mislocalized to the vacuolar membrane. The mutants were also deficient in vacuolar sorting of a multivesicular body (MVB) marker, a ubiquitin–GFP–carboxypeptidase S (Ub–GFP–CPS) fusion protein. Taken together, these results indicate that Pxa1 protein is required for normal vacuole function and morphology in S. pombe.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Tsuyoshi NAKAGAWA, Shinya NAKAMURA, Katsunori TANAKA, Makoto KAWAMUKAI ...
    2008 Volume 72 Issue 2 Pages 624-629
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    We developed a new series of Gateway binary vectors, R4pGWBs, that are plant transformation vectors designed for one-step construction of chimeric genes between any promoter and any cDNA. The structure of R4pGWBs is almost the same as the promoterless type of improved pGWBs (ImpGWBs), except that the attR1 site is replaced with attR4, which enables tripartite recombination of these vectors with promoter- and cDNA-entry clones. While ImpGWBs are suitable for promoter analysis and constitutive expression of cDNAs in higher plants, R4pGWBs have a great advantage in expressing a cDNA under the regulation of desired promoters.
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  • Masaharu TAKEMURA, Kazuto SUGIMURA, Katsuzumi OKUMURA, Siripan LIMSIRI ...
    2008 Volume 72 Issue 2 Pages 630-635
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Immortalized cell lines maintain telomeres by the expression of telomerase or by a mechanism designated alternative lengthening of telomeres (ALT). Although DNA polymerase α (pol-α) is reported to be required for telomere maintenance, the critical role of pol-α in telomere maintenance has not been firmly determined. We examined the role of retinoblastoma protein (pRb) and pol-α in the regulation of telomere length, using telomere-fiber FISH. Telomere length varied dependent on the intracellular abundance of pol-α or pRb in HeLa cells. A proportion of hyper-phosphorylated pRb (ppRb) molecules localized to sites of telomeric DNA replication in HeLa cells. Pol-α might thus contribute to telomere maintenance, and might be regulated by ppRb.
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Food & Nutrition Science Regular Papers
  • Kohei NAKAJIMA, Mai SATO, Makoto HATTORI, Tadashi YOSHIDA, Keiji YOSHI ...
    2008 Volume 72 Issue 2 Pages 295-302
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Ossein gelatin (OG) and low-molecular-weight ossein gelatin (LOG) were conjugated with a glucose/fructose stearic acid monoester (GE/FE), which had been prepared from the hydrolysate of a sucrose stearic acid diester, by the Maillard reaction to improve their physical properties. The molar ratio of each conjugate (GE/FE-OG or GE/FE-LOG) was about 1:1, and the conjugation resulted in a decreased isoelectric point. The GE/FE-OG gel showed a lower storage modulus, melting temperature, and enthalpy change than those for the OG gel at both the early and late stages of gelation, and each gel at pH 3.0 showed somewhat lower characteristics than those at pH 7.0. The conjugates acquired superior emulsifying ability, GE/FE-LOG in particular exhibiting markedly higher emulsifying ability in the acidic pH range, in the presence of NaCl, and over a wide temperature range. It is thus expected that conjugation with GE/FE could be effective for providing a new type of gelatin with a soft texture, easy melting, and emulsifying ability.
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  • Hideaki HARA, Yasuaki ISE, Nobutaka MORIMOTO, Masamitsu SHIMAZAWA, Koj ...
    2008 Volume 72 Issue 2 Pages 335-345
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    We investigated the laxative activity of an extract of agarwood leaves from Aquilaria sinensis. The laxative activity was measured in mice by counting the stool frequency and stool weight, and the drugs were orally administered. An acetone extract of agarwood leaves and senna (a representative laxative drug) both increased the stool frequency and weight, but a methanol extract did not. The laxative effect of the acetone extract was milder than that of the anthraquinoid laxative, senna, and the former did not induce diarrhea as a severe side effect. We identified the main constituent contributing to the laxative effect of the acetone extract as genkwanin 5-O-β-primeveroside (compound 4). Compound 4 strengthened the spontaneous motility and induced contraction in the ileum. This ileal contraction induced by compound 4 was inhibited by atropine, but not by azasetron, suggesting that the effect of compound 4 was mediated by acetylcholine receptors, and not by serotonin. The laxative mechanism for compound 4 may in part involve stimulation of intestinal motility via acetylcholine receptors.
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  • Hyung-Sun YOUN, Hyo Jin LIM, Hwa Jin LEE, Daniel HWANG, Mihi YANG, Rao ...
    2008 Volume 72 Issue 2 Pages 368-375
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Garlic has long been used as a folk medicine. Numerous studies have demonstrated that a garlic extract and its sulfur-containing compounds inhibited nuclear factor kappa B (NF-κB) activation induced by various receptor agonists including lipopolysaccharide (LPS). Toll-like receptors (TLRs) play a key role in sensing diverse microbial products and inducing innate immune responses. The dimerization of TLR4 is required for the activation of downstream signaling pathways, including NF-κB. Therefore, TLR4 dimerization may be one of the first lines of regulation in activating LPS-induced signaling pathways. We report here biochemical evidence that the ethyl acetate fraction of garlic inhibited the LPS-induced dimerization of TLR4, resulting in the inhibition of NF-κB activation and the expression of cyclooxygenase 2 and inducible nitric oxide synthase. Our results demonstrate for the first time that a garlic extract can directly inhibit the TLRs-mediated signaling pathway at the receptor level. These results shed a new insight into understanding how garlic modulates the immune responses that could modify the risk of many chronic diseases.
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  • Jintana WIBOONSIRIKUL, Yukitaka KIMURA, Yumi KANAYA, Takuo TSUNO, Shuj ...
    2008 Volume 72 Issue 2 Pages 384-392
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    A by-product of rice bran oil and protein production was treated with water and compressed hot water at 20 °C to 260 °C for 5 min, and at 200 °C and 260 °C for 5 to 120 min. Each extract was evaluated for its yield, radical scavenging activity, carbohydrate, protein, total phenolic and furfural contents, molecular-mass distribution and antioxidative activity. The maximum yield was obtained at 200 °C. The radical scavenging activity and the protein, total phenolic and furfural contents of the extract increased with increasing temperature. However, the carbohydrate content abruptly decreased when treated at above 200 °C. The extract treated at 260 °C for 5 min exhibited suppressive activity toward the autoxidation of linoleic acid. Each extract obtained at temperatures lower than or equal to 200 °C exhibited emulsifying ability.
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  • Tomoyuki MISHIMA, Shinpei HARINO, Jun SUGITA, Michio NAKAHARA, Tohru S ...
    2008 Volume 72 Issue 2 Pages 393-397
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    In this in vivo study, the time course of plasma concentration and the urinary excretion of ethyl α-D-glucoside (α-EG) and ethyl β-D-glucoside (β-EG) were investigated in rats after a single oral dose of 4 mmol/kg body weight. Maximal plasma concentrations of both α-EG and β-EG (EGs) reached approximately 3 mM at 1 h after oral administration and then decreased rapidly. Approximately 80% of EGs administered were excreted into the urine during the first 6 h. Within 24 h, cumulative urinary α-EG and β-EG excretions were estimated to be 87.2±7.9% and 85.4±5.0%, respectively. Traces of both EGs were detected in plasma and urine 24 h after oral ingestion. The results of this study indicate that almost all of both EGs was rapidly absorbed into the blood stream and easily excreted into the urine after oral administration, and that a small amount of them remained in the rat body 24 h after administration.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Noriko KOMATSUZAKI, Toshihide NAKAMURA, Toshinori KIMURA, Jun SHIMA
    2008 Volume 72 Issue 2 Pages 278-285
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    γ-Aminobutyric acid (GABA) has several physiological functions in humans. We have reported that Lactobacillus paracasei NFRI 7415 produces high levels of GABA. To gain insight into the higher GABA-producing ability of this strain, we analyzed glutamate decarboxylase (GAD), which catalyzes the decarboxylation of L-glutamate to GABA. The molecular weight of the purified GAD was estimated to be 57 kDa by SDS–PAGE and 110 kDa by gel filtration, suggesting that GAD forms the dimer under native conditions. GAD activity was optimal at pH 5.0 at 50 °C. The Km value for the catalysis of glutamate was 5.0 mM, and the maximum rate of catalysis was 7.5 μmol min−1 mg−1. The N-terminal amino acid sequence of GAD was determined, and the gene encoding GAD from genomic DNA was cloned. The findings suggest that the ability of Lb. paracasei to produce high levels of GABA results from two characteristics of GAD, viz., a low Km value and activity at low pH.
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  • Shun’ichi ISHII, Yasuaki HOTTA, Kazuya WATANABE
    2008 Volume 72 Issue 2 Pages 286-294
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Two H-type microbial fuel cells were prepared. The anaerobic chambers were inoculated with rice paddy field soil and fed cellulose as an energy source. In one reactor, the anode and cathode were connected with a wire (closed circuit, CC), while they were not connected in the other reactor (open circuit, OC). The OC reactor actively produced methane. In the CC reactor, however, an electric current of 0.2 to 0.3 mA was constantly generated, and methane production was almost completely suppressed. Electron microscopy revealed that rod-shaped cells with long prosthecae-like filaments were specifically enriched in the CC reactor. Comparisons of 16S rRNA gene clone libraries revealed entirely different phylogenetic compositions in the CC and OC communities; phylotypes related to Rhizobiceae, Desulfovibrio, and Ethanoligenens were specifically enriched in the CC community. The results indicate that electrogenesis resulted in the enrichment of distinctive microbial populations and suppressed methanogenesis from cellulose.
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  • Rattiya WAEONUKUL, Khin Lay KYU, Kazuo SAKKA, Khanok RATANAKHANOKCHAI
    2008 Volume 72 Issue 2 Pages 321-328
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    The effect of polymeric substances such as α-cellulose, birchwood xylan, corn hull, and sugarcane bagasse, and of soluble sugars such as L-arabinose, D-galactose, D-glucose, D-xylose, and cellobiose, on the induction of multienzyme complexes in a facultatively anaerobic bacterium, Paenibacillus curdlanolyticus B-6, was investigated under aerobic conditions. Cells and culture supernatants of strain B-6 grown on different carbon sources were analyzed. Cells grown on each carbon source adhered to cellulose. Hence strain B-6 cells from all carbon sources must have an essential component responsible for anchoring the cells to the substrate surfaces. Native–polyacrylamide gel electrophoresis (native–PAGE), sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE), zymogram analysis, and enzymatic assays indicated that many proteins having xylanolytic and cellulolytic activities from P. curdlanolyticus B-6 grown on each carbon source were produced as two multienzyme complexes in the culture supernatants. These results indicate that P. curdlanolyticus B-6 produced multienzyme complexes when grown on both polymeric and soluble sugars. The multienzyme complexes of P. curdlanolyticus B-6 consisted of the main enzymes and non-enzymatic subunits and the production of some different subunits, depending on the carbon source.
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  • Tatsuya FUJII, Naoki TAKAYA
    2008 Volume 72 Issue 2 Pages 412-420
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Fusarium oxysporum JCM11502 expresses a denitrifying (nitrate (NO3)-respiring) mechanism and can thrive under oxygen (O2) limitation. The fungus reduces NO3 to nitrite at the initial step of denitrification. In this study, we cloned the gene coding NADH-NO3 reductase (NADH-Nar) (niaD) from F. oxysporum JCM11502. The niaD gene complemented the defective NO3 assimilation by mutant strain M10, indicating that the fungus reduced NO3 through NADH-Nar activity and assimilated it like other fungi. We found that the transcription of niaD and the production of NADH-Nar activity were enhanced under O2-limited denitrifying conditions relative to aerobic conditions. Strain M10 produced less NADH-Nar activity and less denitrified product than the wild-type strain. Introducing niaD into the mutant also restored these defects, indicating that niaD is involved in denitrification. These results indicate that the fungus denitrified NO3 through NADH-Nar activity in addition to the ubiquinol-Nar mechanism.
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  • Yoshie NAGAHASHI, Masaaki TAZOE, Tatsuo HOSHINO
    2008 Volume 72 Issue 2 Pages 421-427
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    A novel gene (pdxP) encoding a pyridoxine 5′-phosphate (PNP) phosphatase involved in the last step of pyridoxine biosynthesis was cloned from Sinorhizobium meliloti IFO 14782 on the basis of the peptide sequences of the natural enzyme. The pdxP gene is an open reading frame (708 bp) encoding 235 amino acid residues with a calculated molecular weight of 26,466. From its deduced amino acid sequence, it was predicted that the enzyme belongs to the haloacid dehalogenase superfamily.
    Transformants of Escherichia coli and S. meliloti by pdxP gene expression plasmids showed stimulated PNP phosphatase activities. When pdxP was overexpressed together with the PNP synthase gene (pdxJ) in S. meliloti, the recombinant strain produced 149 mg/l of pyridoxine, 46% and 16% higher than the host strain and the pdxJ recombinant of S. meliloti respectively.
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  • Xiqian LAN, Xin ZHANG, Ritsuko KODAIRA, Zeyang ZHOU, Makoto SHIMOSAKA
    2008 Volume 72 Issue 2 Pages 492-498
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    A gene coding for a second β-N-acetylglucosaminidase (nagB) was isolated from the chitinolytic bacterium Aeromonas hydrophila strain SUWA-9. The nagB open reading frame encoded a polypeptide of 618 amino acid residues with a molecular mass of 68.8 kDa. It did not contain a sequence characteristic of a signal peptide at the N-terminus. The deduced amino acid sequence showed high similarity to those of bacterial β-N-acetylhexosaminidases classified into family 20 of glycosyl hydrolases. The nagB gene was successfully expressed in Escherichia coli, and the recombinant protein hydrolyzed N-acetylchitooligomers from dimer to hexamer and produced monomer as a final product. Reverse transcription-mediated PCR (RT-PCR) analysis revealed that nagB was transcribed when SUWA-9 cells were grown in the presence of colloidal chitin. In the upstream of the nagB gene, three genes, coding for putative N-acetylglucosamine kinase, β-glucosidase, and ATP-binding protein of ABC-type transporter, were identified, and these genes likely to constitute an operon.
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  • Shinya KIMURA, Jun-ichi MARUYAMA, Michio TAKEUCHI, Katsuhiko KITAMOTO
    2008 Volume 72 Issue 2 Pages 499-505
    Published: February 23, 2008
    Released: February 23, 2008
    [Advance publication] Released: February 07, 2008
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    Aspergillus oryzae has numerous protease genes that might cause proteolytic degradation of heterologously-produced proteins. The productivity of the heterologous protein can be improved by protease gene disruption, but it is difficult to select disruption targets efficiently. In this study, we monitored the expression of 132 protease genes by DNA microarray. A group of protease genes up-regulated during cultivation was identified by clustering analysis. In this protease group, the nptB gene encoding neutral protease II was included as well as the alpA, tppA, and pepA genes, disruption of which has improved human lysozyme (HLY) production. The nptB gene was disrupted to investigate its involvement in HLY production, and nptB disruptants showed an improvement in the production. These observations suggest that monitoring the expression of protease genes is an efficient strategy in screening potential disruption targets for heterologous protein production in A. oryzae.
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