Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
74 巻 , 5 号
選択された号の論文の44件中1~44を表示しています
Award Reviews
  • Michinori MATSUO
    2010 年 74 巻 5 号 p. 899-907
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Glucose and lipids are essential to the body, but excess glucose or lipids lead to metabolic syndrome. ATP-binding cassette (ABC) proteins are involved in the homeostasis of glucose and lipid in that they regulate insulin secretion and remove excess cholesterol from the body. Sulfonylurea receptor (SUR) is a subunit of the ATP-sensitive potassium channels, which regulate insulin secretion from pancreatic β-cells by sensing cellular metabolic levels. ABCG1 removes excess cholesterol from peripheral tissues and functions in reverse cholesterol transport to the liver. ABCG5 and ABCG8 suppress the absorption of cholesterol in the intestine and exclude cholesterol from the liver to the bile duct. ABCG1 and ABCG4, expressed in the central nervous system, play roles in lipid metabolism in the brain. These ABC proteins are targets of drugs and functional foods to cure and prevent diabetes, hyperlipidemia, and neurodegenerative diseases. In this review, recent knowledge of the physiological function and regulation of ABC proteins in the homeostasis of glucose and lipids is discussed.
  • Eiji SAKURADANI
    2010 年 74 巻 5 号 p. 908-917
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Studies of the application of functional lipids such as polyunsaturated fatty acids (PUFAs) have been conducted in various fields with a view to health and dietary requirements in a search for novel, rich sources. The filamentous fungus Mortierella alpina 1S-4 produces triacylglycerols rich in arachidonic acid, i.e., ones reaching 20 g/l in concentration and containing 30–70% arachidonic acid as total fatty acids. Various mutants derived from M. alpina 1S-4 have led to the production of oils containing various PUFAs. Molecular breeding of M. alpina strains by means of manipulation of the genes involved in PUFA biosynthesis facilitates improvement of PUFA productivity and elucidation of the functions of their enzymes. This review describes practical PUFA production through mutant breeding, functional analyses of the genes of the enzymes involved in PUFA biosynthesis, and recent advances in unique PUFA production through molecular breeding.
Organic Chemistry Note
Biochemistry & Molecular Biology Regular Papers
  • Hiroaki FUJIMORI, Masayoshi HISAMA, Hiroharu SHIBAYAMA, Atsushi KAWASE ...
    2010 年 74 巻 5 号 p. 918-922
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    To determine the component-activity relationships of phytoncide solutions on inhibitory activity in melanin biosynthesis, four types of phytoncide solution (A-type, AB-type, D-type, and G-type) were evaluated for inhibition of mushroom tyrosinase activity and melanin synthesis on murine B-16 melanoma cells and a human reconstituted skin model. The A-type, AB-type, D-type, and G-type of phytoncide solution treatment resulted in significant inhibition of tyrosinase activity. The amount of melanin was increased by treatment with phytoncide solutions in a concentration-dependent manner on murine B-16 melanoma cells without affecting cell growth. Furthermore, phytoncide solutions also suppressed melanin synthesis in a concentration-dependent manner on a human reconstituted skin model. These effects of A-type solution were superior to those of other solutions.
  • Yuling MI, Caiqiao ZHANG, ChunMei LI, Shinji TANEDA, Gen WATANABE, Aki ...
    2010 年 74 巻 5 号 p. 934-938
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Quercetin, an antioxidant flavonoid, is considered beneficial for human and animal health. In this study, the protective effect of quercetin on oxidative damage to testicular cells was studied in embryonic chickens after treatment with 4-nitro-3-phenylphenol (PNMPP) derived from diesel exhaust particles. Testicular cells were challenged with PNMPP (10−8–10−6 M) alone and in combination with quercetin for 48 h. The results showed that quercetin manifested no deleterious effect on spermatogonial cells up to 1.0 μg/ml. Exposure to PNMPP (10−6 M) induced condensed nuclei and vacuolated cytoplasm and reductions in testicular cell viability and spermatogonial cell numbers (p<0.05). It also induced lipid peroxidation by an elevation of thiobarbituric acid reactive substances and decreased glutathione peroxidase activity and superoxide dismutase activity (p<0.05). Simultaneous supplementation with quercetin restored these parameters to the same levels as in the control. These data indicate that quercetin protects spermatogonial cells from oxidative damage in embryonic chickens intoxicated with PNMPP.
  • Tetsuya KIMURA, Tomomi MIZUTANI, Jia-Lin SUN, Tetsu KAWAZU, Shuichi KA ...
    2010 年 74 巻 5 号 p. 954-960
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    The xylanase B gene encoding a thermostable family 10 xylanase of Clostridium stercorarium was expressed in plants under the control of a constitutive promoter. Two forms of the xylanase B gene, the xynB gene encoding the full length of the xylanase B gene including the bacterial signal sequence and the xynBM gene without the signal sequence region, were introduced into tobacco BY-2 cells and tobacco plants respectively under the control of the cauliflower mosaic virus 35S promoter. Transgenic BY-2 cells and tobacco plants showed xylanase activity and normal growth. The recombinant enzyme produced in transgenic BY-2 cells harboring the xynB gene was secreted into the culture supernatant, and the recombinant enzyme produced in transgenic BY-2 cells harboring the xynBM gene was localized in the cells. In contrast to tobacco plants, expression of the xynB gene under the control of the rice actin promoter in rice plants was toxic to host cells. However, the recombinant XynBM accumulated in leaf cells, and no phenotypic effect of expression of the xynBM gene was observed. Enzyme activity was maintained in cell-free extracts of transgenic rice leaves at 60 °C for 72 h, and the recombinant XynBM degraded hemicellulosic polymers in cell-free extracts of transgenic rice leaves.
  • Eun-Sun HWANG, Kwang-Kyun PARK
    2010 年 74 巻 5 号 p. 961-967
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Magnolol, a hydroxylated biphenyl compound isolated from the root and stem bark of Magnolia officinalis, has been reported to have anticancer activity, but little is known about its molecular mechanisms of action. Increased expression of cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism, has been identified in many cancer types. Matrix metalloproteinases (MMPs) are enzymes involved in various steps of metastasis development. The objective of this study was to study the effects of magnolol on cancer invasion and metastasis using PC-3 human prostate carcinoma cells. Cellular proliferation was determined by MTT colorimetric assay. Magnolol inhibited cell growth in a dose-dependent manner. In an invasion assay conducted in Transwell chambers, magnolol showed 33 and 98% inhibition of cancer cell at 10 μM and 20 μM concentrations, respectively, compared to the control. The expression of MMP-2/-9 and COX-1/-2 was assessed by gelatin zymography and Western blot respectively. The protein and mRNA levels of both MMP-2 and MMP-9 were down-regulated by magnolol treatment in a dose-dependent manner. These results demonstrate the antimetastatic properties of magnolol in inhibiting the adhesion, invasion, and migration of PC-3 human prostate cancer cells.
  • Yoshito NAKANISHI, Shengmin ZHOU, Sang-Wan KIM, Shinya FUSHINOBU, Jun- ...
    2010 年 74 巻 5 号 p. 984-991
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    We cloned a bacterial copper-containing nitrite reductase (NirK) homolog gene of Aspergillus oryzae (AonirK). Alignment showed that amino acid residues crucial for copper binding are conserved in the deduced sequence of the fungal protein. The recombinant protein exhibited distinct nitrite reductase activity, and its absorption and EPR spectra showed the presence of type 1 and type 2 copper atoms in the molecule. AonirK transcriptionally responded to denitrification conditions. Although the denitrifying activity of A. oryzae was weak under the conditions employed, high expression of the gene in the fungal cells enhanced the denitrifying activity 6-fold, accompanied by distinct cell growth. Furthermore, the highly expressed AoNirK was subcellularly localized to the mitochondria. The results demonstrated that AoNirK is responsible for fungal denitrification. Discussion is added on the novel insight concerning the origin and evolution of the mitochondrion provided by the findings for eukaryotic NirKs.
  • Faujan Bin H. AHMAD, Mansour GHAFFARI MOGHADDAM, Mahiran BASRI, Mohd B ...
    2010 年 74 巻 5 号 p. 1025-1029
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    An easy and efficient strategy to prepare betulinic acid esters with various anhydrides was used by the enzymatic synthesis method. It involves lipase-catalyzed acylation of betulinic acid with anhydrides as acylating agents in organic solvent. Lipase from Candida antarctica immobilized on an acrylic resin (Novozym 435) was employed as a biocatalyst. Several 3-O-acyl-betulinic acid derivatives were successfully obtained by this procedure. The anticancer activity of betulinic acid and its 3-O-acylated derivatives were then evaluated in vitro against human lung carcinoma (A549) and human ovarian (CAOV3) cancer cell lines. 3-O-glutaryl-betulinic acid, 3-O-acetyl-betulinic acid, and 3-O-succinyl-betulinic acid showed IC50<10 μg/ml against A549 cancer cell line tested and showed better cytotoxicity than betulinic acid. In an ovarian cancer cell line, all betulinic acid derivatives prepared showed weaker cytotoxicity than betulinic acid.
  • Kazutake HIROOKA, Yasutaro FUJITA
    2010 年 74 巻 5 号 p. 1030-1038
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Bacillus subtilis quercetin 2,3-dioxygenase (QdoI) catalyzes the C-ring cleavage of quercetin to yield 2-protocatechuoyl-phloroglucinol carboxylic acid and carbon monoxide. The recombinant QdoI effectively decomposed several flavonols, including quercetin, whereas its activity toward fisetin was low, suggesting that the 5-hydroxyl group at the A-ring is critical for substrate recognition. A B. subtilis mutant with derepressed QdoI activity was much more sensitive to quercetin than the wild type, but did not exhibit similar sensitivity toward the other flavonoids tested. Further analysis, including co-cultivation with the wild type and the mutant, led to the assumption that intracellular accumulation of protocatechuic acid derived from the rapid decomposition of quercetin severely affects cell viability. Although protocatechuic acid is also produced by fisetin degradation, cell death was avoided, probably due to the lower activity of QdoI toward fisetin. The sensitivity of the B. subtilis mutant toward quercetin was quenched by repression of QdoI by the use of its authentic repressors. Moreover, this adverse effect of excess QdoI with quercetin was also exerted on Escherichia coli cells. This implies the availability of the QdoI regulatory system as a novel selection marker for genetic transformation without using antibiotic-resistant ones.
  • Deyong YANG, Xishuang SONG, Jianing ZHANG, Lin YE, Shujing WANG, Xiang ...
    2010 年 74 巻 5 号 p. 1039-1044
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Apoptosis deficiency is a hallmark of many cancer cells. Functional suppression of specific antiapoptotic factors might provide a feasible strategy in cancer gene therapy. Livin, the latest found inhibitor of apoptosis protein (IAP) family member, plays important role in cell growth and apoptosis. It has been reported that Livin is highly expressed in bladder cancer tissues. In this study, we found that, unlike other cancer cell lines, there was only Livin-α not Livin-β expression in bladder cancer cell lines. We further investigated the effects of Livin knockdown on human bladder cancer T24 cell growth and apoptosis. We found that small interfering RNA (siRNA) mediated Livin suppression significantly inhibited T24 cell proliferation and colony formation ability. Livin knockdown dramatically increased the T24 cell apoptotic rate in response to different proapoptotic stimuli, such as Mitomycin and TNF-alpha, and this was associated with caspase-3 and caspase-9 activation. These results suggest that Livin knockdown can inhibit cell growth and increase sensitivity to apoptotic stimuli, and might serve as a potent target in bladder cancer gene therapy.
  • Tadamasa SASAKI, Haruko AKUTSU, Hiroaki SHIMADA, Shigetoshi MIURA
    2010 年 74 巻 5 号 p. 1045-1049
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Cytochrome P450s are widespread in the plant kingdom. The functions of plant P450s are dispersed through many aspects of plant metabolisms, which are involved in the biosynthesis of defense compounds and protectants against ultraviolet rays, as well as metabolic pathways for the biosynthesis and/or degradation of fatty acids, hormones, and signaling molecules. We found a gene for rice P450, OsCYP84A, which was classified into CYP84A in the CYP71 clan. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that this gene was ubiquitously expressed without any temporal and spatial specificity under normal growth conditions, but its expression was inducibly and significantly increased by ultraviolet (UV)-B and UV-C irradiation. Rice transformants in which OsCYP84A expression was suppressed by the antisense gene showed apparent growth retardation with obvious symptoms of damage on the plant bodies under UV-B irradiation, although no phenotypic alteration occurred under normal growth conditions. These results suggest the existence of a novel UV-tolerance system involving OsCYP84A.
  • Faiçal BRINI, Walid SAIBI, Imen AMARA, Ali GARGOURI, Khaled MAS ...
    2010 年 74 巻 5 号 p. 1050-1054
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Group-2 late embryogenesis abundant (LEA) proteins, also known as dehydrins, are claimed to stabilize macromolecules against damage caused by freezing, dehydration, ionic or osmotic stresses. However, their precise function remains unknown. Here, we investigated the effect of wheat dehydrin (DHN-5) protein on the activity and thermostability of two distinct enzymes, β-glucosidase (bglG) and glucose oxidase/peroxidase (GOD/POD) in vitro. The purified DHN-5 protein had the capacity to preserve and stabilize the activity of bglG subjected to heat treatment. In addition, DHN-5 stabilized oxidizing enzymes, as it improved reliability in measuring glucose concentrations with a glucose oxidase/peroxidase (GOD/POD) kit while the temperature increased from 37 to 70 °C. All together the data presented provide evidence that DHN-5 is a dehydrin able to preserve enzyme activities in vitro from adverse effects induced by heating.
  • Yu CAO, Nan JIN, Hui XU, Yi LIU, Wei Hua ZHU, Xin Ran LI, Dai Rong QIA ...
    2010 年 74 巻 5 号 p. 1073-1078
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Complex I is the first enzyme in the mitochondrial respiratory chain. It extracts energy from NADH, which is produced by the oxidation of sugars and fats, and traps the energy by virtue of a potential difference or voltage across the mitochondrial inner membrane. Herein, the genomic sequence and four splice variants encoding the complex I 19-kD subunit were isolated from Dunaliella salina. There were four transcripts coding for the complex I 19-kD subunit due to alternative splicing in algae, and the four transcripts were translated to two protein isoforms with varying C-terminals. We report the splicing pattern in the 3′-region of the D. salina 19-kD subunit, in which three of the exons (5, 6, and 7) could be alternatively spliced. Moreover, we found that four alternatively spliced variants were subject to coordinated transcription in response to different stresses by real-time quantitative PCR.
  • Satoshi TAKENAKA, Satoshi WAKAI, Hideyuki TAMEGAI, Susumu UCHIYAMA, Yo ...
    2010 年 74 巻 5 号 p. 1079-1083
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Homologous cytochromes c5 from a mesophile, Shewanella amazonensis (SA cytc5), and a psychrophile, Shewanella violacea (SV cytc5), were compared to elucidate the molecular mechanisms underlying protein stability and function. Cyclic voltammetry revealed that the two proteins had the same redox potential value. Differential scanning calorimetry showed that SV cytc5 was more stable than SA cytc5 in an enthalpic manner. These results and the structure model of Shewanella oneidensis cytochrome c5 indicated that hydrophobic heme environments in the two proteins are the same to maintain the same redox potential value, and that the intra-molecular interactions in SV cytc5, perhaps involved in Lys-50 and Tyr-73, account for its higher stability. Electron transfer from SV cytc5 to membrane proteins of S. violacea and S. amazonensis was faster than that from SA cytc5, suggesting that solvent-exposed Lys-4 in SV cytc5 is responsible for the faster association and dissociation between SV cytc5 and its redox partner.
Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Takayuki KOYANO, Kazunori KUME, Manabu KONISHI, Takashi TODA, Dai HIRA ...
    2010 年 74 巻 5 号 p. 1129-1133
    発行日: 2010/05/23
    公開日: 2010/05/23
    ジャーナル フリー
    In eukaryotes, cell polarity is essential for cell proliferation, differentiation, and development. It is regulated in 3 steps: establishment, maintenance, and transition. Compared to current knowledge of establishment and maintenance, the mechanism regulating the transition of cell polarity is poorly understood. In fission yeast during the G2 phase, growth polarity undergoes a dramatic transition, from monopolar to bipolar growth (termed NETO: new end take off). In this study, we screened systematically for protein kinases related to NETO using a genome-wide kinase deletion library. Analysis of these deletions suggested that 35 and 2 kinases had a putative positive and a negative role, respectively, in NETO. Moreover, 5 kinases were required for NETO-delay in the G1-arrested cdc10 mutant. These results suggest that many signaling pathways are involved in the regulation of NETO.
Food & Nutrition Science Regular Papers
  • Wichai CHERDSHEWASART, Wandee SUTJIT, Kade PULCHAROEN, Malyn CHULASIRI
    2010 年 74 巻 5 号 p. 923-927
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Butea superba is a traditional tuberous Thai plant enriched with flavonoids that is used for treating erectile dysfunction. We investigated the mutagenic and antimutagenic potentials of a B. superba extract by using the pre-incubation method of the Ames test. Salmonella typhimurium strains TA 98 and TA 100 were applied as the tester strains in the presence and absence of an S9 mixture. Prior to the mutagenic and antimutagenic tests, the survival of the tester strains was measured by treating with the B. superba extract. The results show that the B. superba extract exhibited dose-dependent cytotoxic effects. Data from the Ames test revealed that the B. superba extract to be non-mutagenic in the presence and absence of the S9 mixture. In contrast, the B. superba extract showed antimutagenic potential towards either or both of the tested mutagens: 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and benzo(a)pyrene (B(a)P) in the respective presence and absence of the S9 mixture, respectively. The plant antimutagenic activity was confirmed by a rec assay. A further study by micronucleus test demonstrated that the B. superba extract at the maximum loading volume could induce acute micronucleus formation in the tested animals. The in vitro mutagenic and antimutagenic assays confirmed the safe consumption of B. superba products at low dose (not more than 781.25 μg/ml of the plant extract), but the in vivo genotoxic assay demonstrated the unsafe consumption at a high dose (300 mg/kg of the BW plant extract or 16 g/kg of the BW plant powder).
  • Kazuyoshi NAMBA, Michiko HATANO, Tomoko YAESHIMA, Mitsunori TAKASE, Ku ...
    2010 年 74 巻 5 号 p. 939-945
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Twenty-seven elderly subjects (mean age 86.7±6.6 years) were pre-administered a test food containing 1×1011 cfu of BB536 daily for 5 weeks (P1), during which they also received influenza vaccination at week 3. The subjects were then randomized to a BB536 group and a placebo group for 14 weeks (P2). The proportion of subjects who contracted influenza was significantly lower in BB536 group than in the to placebo group. The proportion of subjects with fever was also significantly lower in the BB536 group than in the placebo group. In the P1 period, the NK cell activity and the bactericidal activity of the neutrophils were significantly higher at week 5 than to before BB536 administration. In the P2 period, although NK cell activity and neutrophilic activities declined at the end of the study in both the placebo and the BB536 group, neutrophil phagocytic activity and NK cell activity tended to maintain slightly higher levels in the BB536 group than in the placebo group. These results suggest that continuous ingestion of BB536 reduces the incidence of influenza and fever, probably by potentiating innate immunity.
  • Xiujuan WANG, Dongmei WANG, Jiaxian LI, Chuangxing YE, Kikue KUBOTA
    2010 年 74 巻 5 号 p. 946-953
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Three types of Cocoa tea, green, oolong, and black, were prepared from fresh young leaves of Camellia ptilophylla. Their aroma characteristics were compared by a sensory evaluation with corresponding traditional tea samples made from C. sinensis. The aroma profile of Cocoa green tea was quite different from that of traditional green tea, but fermented Cocoa oolong tea and black tea showed aroma profiles similar to those of traditional oolong tea and black tea. Cocoa green tea contained vanillin as the most abundant aroma constituent. Almost the same aroma compounds of jasmine lactone, indole and monoterpene alcohols, which are known as important aroma constituents in commercial oolong tea and black tea, were identified as the main aroma compounds in the fermented Cocoa tea types. The composition of these aroma compounds well explained the aroma profile of each Cocoa tea. The monoterpene alcohols seemed to be released during fermented tea manufacture, because seventeen glycosides consisting of the aglycons of terpene alcohols were identified in Cocoa tea leaves, and hydrolytic activity of crude enzymes in the p-nitrophenol glycoside substrate was also detected.
  • Takeshi TSURUTA, Ryo INOUE, Toshihiko IWANAGA, Hiroshi HARA, Takaji YA ...
    2010 年 74 巻 5 号 p. 968-973
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Some commensal intestinal bacteria in humans and mice are coated with secretory immunoglobulin A (S-IgA). It has been suggested that the S-IgA coating of commensal bacteria does not occur at random and thus identification of S-IgA-coated bacterial genera/species should help in elucidating the interaction between S-IgA and commensal intestinal bacteria, but no method of identifying the genera/species of S-IgA-coated bacteria has been established. To identify S-IgA-coated bacterial composition, we developed a method combining immunohistochemical detection of S-IgA and subsequent 16S rRNA targeted fluorescence in situ hybridization (FISH) analysis. Human and mouse fecal S-IgA coated bacterial composition was evaluated by this newly developed method with 10 frequently-used FISH probes. Fecal S-IgA-coated bacterial composition was successfully analyzed by this method, and this suggests that Enterobacteriaceae is preferably coated with S-IgA, whereas Bacteroides/Prevotella and Lactobacillus/Enterococcus groups appear to be poorly coated with S-IgA.
  • Yuko KITAMURA, Yukiko WASHINO, Eriko KOGA, Ayaka ITO, Maiko KAWAGOE, C ...
    2010 年 74 巻 5 号 p. 979-983
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Rat liver was subjected to two-thirds warm ischemia for 45 min and reperfusion (I/R) to evaluate the resulting oxidative stress. The plasma alanine aminotransferase and aspartate aminotransferase activities were significantly higher than those in the sham group 1.5–24 h after I/R, showing extensive liver cell death. The level of oxidative stress was compared between the ischemic and non-ischemic regions based on the change in antioxidative vitamins C and E. The vitamin C level was significantly decreased during I/R in both the ischemic and non-ischemic regions 0, 1.5, 3, 6, 12, and 24 h after the start of reperfusion, showing enhanced oxidative stress even in the non-ischemic lobules. This decrease of vitamin C in the ischemic region was significantly higher than that in the non-ischemic lobules, while the vitamin E content was decreased only in the ischemic lobes, demonstrating higher oxidative stress in the ischemic region than that in the non-ischemic region. Early transient activation of cytoprotective extracellular signal-related kinase (ERK) was apparent in both the ischemic and non-ischemic lobules, reflecting oxidative stress in both regions. Early transient activation of c-Jun NH2-terminal kinase (JNK) was only apparent in the ischemic region, corresponding to extensive oxidative stress and liver cell death. These results demonstrate that significant oxidative stress was induced, but that JNK leading to cell death was not activated in the non-ischemic part of the liver.
  • Azzedine MAZARI, Satoshi IWAMOTO, Ryo YAMAUCHI
    2010 年 74 巻 5 号 p. 1013-1017
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Unilamellar liposomes of phosphatidylcholines (PCs), 1-palmitoyl-2-linoleoyl-3-sn-PC (PLPC), 1-linoleoyl-2-palmitoyl-3-sn-PC (LPPC), and a 1:1 mixture of 1,2-dilinoleoyl-3-sn-PC and 1,2-dipalmitoyl-3-sn-PC (DLPC/DPPC), were peroxidized by the addition of a water-soluble 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) and of a lipid-soluble 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (MeOAMVN). LPPC liposomes showed the lowest oxidizability and kinetic chain-length values on AAPH-initiated peroxidation. On MeOAMVN-initiated peroxidation, PLPC liposomes with their lower peroxidation kinetic values were more stable than LPPC or DLPC/DPPC liposomes. The incorporation of cholesterol into the liposomes induced dose-dependent inhibition of PLPC and of LPPC peroxidation, while its effect was less important for the DLPC/DPPC liposomes. Our results indicate that the sn-position of unsaturated acyl chains and the cholesterol content are important modulating factors in the oxidizability of membrane phospholipids.
  • Hirotaka SEKIGUCHI, Kazuhiro IRIE, Akira MURAKAMI
    2010 年 74 巻 5 号 p. 1018-1024
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Helicobacter pylori (H. pylori) is a major human pathogen and plays a central role in chronic gastritis and gastric cancer. Since the adhesion of H. pylori to the human gastric epithelium is the initial and critical step of its infection, anti-H. pylori adhesion agents may be effective for the prevention and therapy of H. pylori-associated diseases. CD74 has recently been identified as a new receptor for H. pylori urease, and we have previously reported that several citrus components strongly suppressed CD74 expression in NCI-N87 gastric carcinoma cells. We found in this present study that auraptene (citrus coumarin) disrupted serum starvation-induced extracellular signaling-regulated kinase (ERK) 1/2 activation and attenuated H. pylori adhesion and IL-8 production in a co-culture system. In addition, the knockdown of CD74 expression led to a significant decrease of H. pylori adhesion, but unexpectedly increased IL-8 production. However, PD98059 (a MEK1/2 inhibitor) dramatically down-regulated this cytokine, suggesting MEK/ERK-dependent IL-8 production. Our results suggest that auraptene suppressed H. pylori adhesion and resulting chemokine production by disrupting ERK1/2 activation.
  • Syoji SAKAKIBARA, Ryuichiro MURAKAMI, Mikio TAKAHASHI, Takashi FUSHIMI ...
    2010 年 74 巻 5 号 p. 1055-1061
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    This study examined the effect of acetate on endothelial nitric oxide synthase (eNOS) in human umbilical vein endothelial cells (HUVECs) by immunoblotting assay and the ability of acetic acid to upregulate flow-mediated vasodilatation in humans. In HUVECs, acetate induced a biphasic increase in the phosphorylated form of eNOS. The amount of phosphorylated eNOS was significantly increased by exposure to 200 μmol/l acetate for 20 min (early phase) and for 4 h (late phase). The inhibitors of cAMP-dependent protein kinase (PKA) and AMP-activated protein kinase (AMPK) blocked acetate-induced eNOS phosphorylation in the early and the late phase respectively. Furthermore, in postmenopausal women, maximum forearm blood flow (FBF) in response to shear stress increased in the vinegar (acetic acid) administered group compared to the placebo group. These results suggest that acetic acid-induced eNOS phosphorylation contributes to upregulation of flow-mediated vasodilatation in humans.
  • Nhung Thuy DANG, Rie MUKAI, Ken-ichi YOSHIDA, Hitoshi ASHIDA
    2010 年 74 巻 5 号 p. 1062-1067
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Diabetes mellitus is a complex disease that is characterized by the defection of insulin sensitivity in such peripheral tissues as skeletal muscle, adipose tissue and liver. We have previously demonstrated that certain inositol derivatives stimulated glucose uptake accompanied by the translocation of glucose transporter 4 (GLUT4) to the plasma membrane in L6 myotubes. We investigated in this present study whether an oral intake of D-pinitol (PI) and myo-inositol (MI) would affect GLUT4 translocation in the skeletal muscle of mice. PI or MI at 1 g/kg BW administered orally to mice 30 min before a post-oral injection of glucose at 2 g/kg BW resulted in both PI and MI increasing GLUT4 translocation in the skeletal muscle and lowering the plasma glucose and insulin levels. PI and MI, therefore, have the potential to prevent diabetes mellitus by reducing the postprandial blood glucose level and stimulating GLUT4 translocation in the skeletal muscle.
  • Yukiko OKUMURA, Masataka NARUKAWA, Yusaku IWASAKI, Aiko ISHIKAWA, Hisa ...
    2010 年 74 巻 5 号 p. 1068-1072
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    We searched in this study for novel agonists of transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and transient receptor potential cation channel, subfamily A, member 1 (TRPA1) in pepper, focusing attention on 19 compounds contained in black pepper. Almost all the compounds in HEK cells heterogeneously expressed TRPV1 or TRPA1, increased the intracellular Ca2+ concentration ([Ca2+]i) in a concentration-dependent manner. Among these, piperine, isopiperine, isochavicine, piperanine, pipernonaline, dehydropipernonaline, retrofractamide C, piperolein A, and piperolein B relatively strongly activated TRPV1. The EC50 values of these compounds for TRPV1 were 0.6–128 μM. Piperine, isopiperine, isochavicine, piperanine, piperolein A, piperolein B, and N-isobutyl-(2E,4E)-tetradeca-2,4-diamide also relatively strongly activated TRPA1, the EC50 values of these compounds for TRPA1 were 7.8–148 μM. The Ca2+ responses of these compounds for TRPV1 and TRPA1 were significantly suppressed by co-applying each antagonist. We identified in this study new transient receptor potential (TRP) agonists present in black pepper and found that piperine, isopiperine, isochavicine, piperanine, piperolein A, and piperolein B activated both TRPV1 and TRPA1.
Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Satoru TOMITA, Tomohiro IRISAWA, Naoto TANAKA, Tomoo NUKADA, Eiichi SA ...
    2010 年 74 巻 5 号 p. 928-933
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    The contents, components, and synthesis genes of cell wall teichoic acid (WTA) in 18 strains of Lactobacillus plantarum were compared. The WTA of each strain was classified by its components as being either the glycerol- or the ribitol-type. The different strains in the WTA type showed marked differences also in two gene regions, tagD1–tagF2 and lp_1816–tagB2, as for the presence or absence, nucleotide sequences, and transcriptional activities. Our results clearly showed that the tagD1–tagF2 and lp_1816–tagB2 regions contained the synthesis genes of the WTA backbone of L. plantarum. We verified that the genes in the tagD1–tagF2 region were involved in the synthesis of the glycerol-type backbone. Furthermore, we propose that the genes in the lp_1816–tagB2 region were tarI, tarJ, tarK, and tarL, which are involved in the synthesis of the ribitol-type backbone.
  • Chang-Hua SHANG, Liang SHI, Ang REN, Lei QIN, Ming-Wen ZHAO
    2010 年 74 巻 5 号 p. 974-978
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    A homology-based PCR method was used to clone a cDNA encoding lanosterol synthase (LS) from Ganoderma lucidum (G. lucidum), which produces triterpenes. The cDNA of the LS (GenBank accession no. GQ169528) was found to contain an open reading frame (ORF) of 2,181 bp encoding a 726 amino acid polypeptide, whereas the LS genomic DNA sequence (GenBank accession no. GQ169529) consists of 2,924 bp. Functional complementation of G. lucidum LS (Gl-LS) in an erg7 yeast strain lacking LS activity demonstrated that the cloned cDNA encoded a functional LS. Analysis of the Gl-LS transcript profiles revealed a positive correlation between the pattern of LS gene expression and triterpenes content changes in G. lucidum during development. Up-regulation of expression of the Gl-LS gene by methyl jasmonate (MeJA) in the mycelia was also demonstrated by real-time RT-PCR. Up-regulation of the Gl-LS promoter activity by MeJA was also investigated.
  • Kenji WASHIO, Siew Ping LIM, Niran ROONGSAWANG, Masaaki MORIKAWA
    2010 年 74 巻 5 号 p. 992-999
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Pseudomonas sp. MIS38 produces an effective biosurfactant named arthrofactin, which is a cyclic lipopeptide synthesized by a mega complex composed of three nonribosomal peptide synthetases. In order to gain insight into the control mechanism of arthrofactin production, a Tn5 mutant library was constructed and screened for arthrofactin-deficient mutants. Along with a number of mutations that occurred in the arthrofactin synthetase operon, three other mutants harbored distinct Tn5 insertions in the genes encoding SyrF-like protein (arfF), heat shock protein (htpG), and (p)ppGpp synthetase/hydrolase (spoT). Epistasis analyses revealed that spoT functions early in the arthrofactin production pathway. We also found that spoT affects MIS38 swarming, biofilm formation, and the cell morphology.
  • Hiroto MORITA, Ken-Ichi KURIYAMA, Noritaka AKIYAMA, Ayako OKAMOTO, You ...
    2010 年 74 巻 5 号 p. 1000-1006
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    Carboxypeptidase O from Aspergillus oryzae IAM2640 is a serine-type carboxypeptidase. In this study, we cloned and sequenced cDNA and genomic DNA carrying ocpO encoding carboxypeptidase O. The results showed that the length of ocpO was 1,816 bp, and the open reading frame encoded a putative preproenzyme composed of 472 amino acid residues of the mature carboxypeptidase O and an additional N-terminal sequence of 50 amino acid residues. A BLASTN search revealed that a gene, AO090020000351, in A. oryzae RIB40, which is strain used in genome-wide sequencing, is a homolog of ocpO. The difference between AO090020000351 and ocpO was only one nucleotide. The difference caused substitution of Ala for Pro at the 277th position of the enzyme; therefore the protein encoded by AO090020000351 was overproduced and purified. The purified protein showed enzymatic properties similar to carboxypeptidase O, indicating that carboxypeptidase O and protease encoded by AO090020000351 are same enzyme.
  • Tsuyoshi SUGIO, Tomoe KOMODA, Yuko OKAZAKI, Yuki TAKEDA, Sousaku NAKAM ...
    2010 年 74 巻 5 号 p. 1007-1012
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    The iron-oxidizing bacterium Acidithiobacillus ferrooxidans MON-1 is highly resistant not only to mercuric chloride (HgCl2) but also to organomercurials such as methylmercury chloride (MMC). We have found that cytochrome c oxidase, purified from strain MON-1, reduces Hg2+ to volatilizable metal mercury (Hg0) with reduced mammalian cytochrome c or Fe2+ as an electron donor. In this study we found that cytochrome c oxidase can volatilize Hg0 from MMC as well as from Hg2+ with reduced mammalian cytochrome c or c-type cytochrome purified from strain MON-1 as an electron donor. We also found that MMC-Hg0 volatilization activity is present in the MON-1 plasma membrane but not in the cytosol. These activities were strongly inhibited by sodium cyanide (NaCN) and the antibody produced against purified MON-1 cytochrome c oxidase. This is the first report to indicate that cytochrome c oxidase is involved in the degradation of organomercurials in microorganisms.
  • Emiko SHINAGAWA, Osao ADACHI, Yoshitaka ANO, Toshiharu YAKUSHI, Kazuno ...
    2010 年 74 巻 5 号 p. 1084-1088
    発行日: 2010/05/23
    公開日: 2010/05/23
    [早期公開] 公開日: 2010/05/07
    ジャーナル フリー
    3-Dehydroshikimate dehydratase (DSD) is the first known enzyme catalyzing aromatization from 3-dehydroshikimate (DSA) to protocatechuate (PCA). Differently from cytosolic DSD (sDSD), a membrane-bound 3-dehydroshikimate dehydratase (mDSD) was found for the first time in the membrane fraction of Gluconobacter oxydans IFO 3244, and DSA was confirmed to be the direct precursor of PCA. In contrast to weak and instable sDSD, the abundance of mDSD in the membrane fraction suggested the metabolic significance of mDSD as the initial step in aromatization. mDSD was solubilized only by a detergent and was readily purified to high homogeneity. Its molecular weight was estimated to be 76,000. Purified mDSD showed a sole peak at 280 nm in the absorption spectrum and no critical cofactor requirements. The Km of DSA was measured at 0.5 mM, and the optimum pH was observed at pH 6–8. mDSD appeared to react only with DSA, and was inert to other compounds, such as 3-dehydroquinate, quinate, and shikimate.
Microbiology & Fermentation Technology Notes
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