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91.
Katsunori Yanagawa Michinari Sunamura Mark Alexander Lever Yuki Morono Akihiro Hiruta Osamu Ishizaki 《Geomicrobiology journal》2013,30(2):118-129
In this study, we investigated the diversity and spatial distribution of anaerobic methanotrophic archaea (ANMEs) in sediments of a gas hydrate field off Joetsu in the Japan Sea. Distribution of ANMEs in sediments was identified by targeting the gene for methyl coenzyme M reductase alpha subunit (mcrA), a phylogenetically conserved gene that occurs uniquely in methanotrophic and methanogenic archaea, in addition to 16S rRNA genes. Quantitative PCR analyses of mcrA genes in 14 piston core samples suggested that members of ANME-1 group would dominate AOM communities in sulfate-depleted sediments, even below the sulfate-methane interface, while ANME-2 archaea would prefer to populate in shallower sediments containing comparatively higher sulfate concentrations. These results suggest that, although the potential electron acceptors in sulfate-depleted habitats remain elusive, the niche separation of ANME-1 and -2 may be controlled by in situ concentration of sulfate and the availability in sediments. 相似文献
92.
Takahito Tamai Osamu Yamaguchi Shungo Hikoso Toshihiro Takeda Manabu Taneike Takafumi Oka Jota Oyabu Tomokazu Murakawa Hiroyuki Nakayama Yoshihiro Uno Kyoji Horie Kazuhiko Nishida Nahum Sonenberg Ajay M. Shah Junji Takeda Issei Komuro Kinya Otsu 《The Journal of biological chemistry》2013,288(14):10176-10187
Cardiomyocytes proliferate during fetal life but lose their ability to proliferate soon after birth and further increases in cardiac mass are achieved through an increase in cell size or hypertrophy. Mammalian target of rapamycin complex 1 (mTORC1) is critical for cell growth and proliferation. Rheb (Ras homologue enriched in brain) is one of the most important upstream regulators of mTORC1. Here, we attempted to clarify the role of Rheb in the heart using cardiac-specific Rheb-deficient mice (Rheb−/−). Rheb−/− mice died from postnatal day 8 to 10. The heart-to-body weight ratio, an index of cardiomyocyte hypertrophy, in Rheb−/− was lower than that in the control (Rheb+/+) at postnatal day 8. The cell surface area of cardiomyocytes isolated from the mouse hearts increased from postnatal days 5 to 8 in Rheb+/+ mice but not in Rheb−/− mice. Ultrastructural analysis indicated that sarcomere maturation was impaired in Rheb−/− hearts during the neonatal period. Rheb−/− hearts exhibited no difference in the phosphorylation level of S6 or 4E-BP1, downstream of mTORC1 at postnatal day 3 but showed attenuation at postnatal day 5 or 8 compared with the control. Polysome analysis revealed that the mRNA translation activity decreased in Rheb−/− hearts at postnatal day 8. Furthermore, ablation of eukaryotic initiation factor 4E-binding protein 1 in Rheb−/− mice improved mRNA translation, cardiac hypertrophic growth, sarcomere maturation, and survival. Thus, Rheb-dependent mTORC1 activation becomes essential for cardiomyocyte hypertrophic growth after early postnatal period. 相似文献
93.
Chisato Kusunoki Liu Yang Takeshi Yoshizaki Fumiyuki Nakagawa Atsushi Ishikado Motoyuki Kondo Katsutaro Morino Osamu Sekine Satoshi Ugi Yoshihiko Nishio Atsunori Kashiwagi Hiroshi Maegawa 《Biochemical and biophysical research communications》2013,430(1):225-230
Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid (ω3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of ω3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with ω3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). ω3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with ω3-PUFA prevented H2O2-induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress. 相似文献
94.
Maki Seki Osamu Tsuruta Ryo Tatsumi Aki Soejima 《Bioorganic & medicinal chemistry letters》2013,23(14):4230-4234
A novel series of pyrrolidine derivatives as Na+ channel blockers was synthesized and evaluated for their inhibitory effects on neuronal Na+ channels. Structure–activity relationship (SAR) studies of a pyrrolidine analogue 2 led to the discovery of 5e as a potent Na+ channel blocker with a low inhibitory action against human ether-a-go-go-related gene (hERG) channels. Compound 5e showed remarkably neuroprotective activity in a rat transient middle cerebral artery occlusion (MCAO) model, suggesting that 5e would act as a neuroprotectant for ischemic stroke. 相似文献
95.
Minoru Tanaka Xin Li Hidemasa Hikawa Takafumi Suzuki Katsuhiko Tsutsumi Masashi Sato Osamu Takikawa Hideharu Suzuki Yuusaku Yokoyama 《Bioorganic & medicinal chemistry》2013,21(5):1159-1165
Indoleamine 2,3-dioxygenase (IDO) plays a significant role in several disorders such as Alzheimer’s disease, age-related cataracts and tumors. A series of novel tryptoline derivatives were synthesized and evaluated for their inhibitory activity against IDO. Substituted tryptoline derivatives (11a, 11c, 11e, 12b and 12c) were demonstrated to be more potent than known inhibitor MTH-Trp. Suzuki–Miyaura cross-coupling reaction of 11a–d with phenylboronic acid proceeded in high yields. In most cases, C5 and C6 substitutions on the corresponding indole ring were well tolerated. The tryptoline derivative 11c is a promising chemical lead for the discovery of novel IDO inhibitors. 相似文献
96.
Purified glycerol oxidase from Aspergillus japonicus AT 008 was homogeneous by ultracentrifugation and acrylamide gel electrophoresis. The molecular weight was determined to be 400,000 by sedimentation equilibrium, and the isoelectric point was found to be 4.9 by isoelectric focusing. The enzyme showed spectral characteristics of a heme protein. The reduced form possessed absorption maxima at 557 and 430 nm and the oxidized one at 557, 530, 420, 280, and 238 nm. The heme in the enzyme was identified as protoheme IX (one mol per mol of enzyme protein).Glycerol was the best substrate for the enzyme, and the Km value for glycerol was determined to be 10.4 mm. Dihydroxyacetone was oxidized at 59% of that for glycerol, but glycerol 3-phosphate, dihydroxyacetone phosphate, methanol, and ethanol were not oxidized at all. The enzyme had an optimal pH at 7.0 with glycerol as substrate, and the enzymatic activity increased by treatment in alkaline pH. The enzyme was also activated by addition of several divalent metal ions including Zn2+, Ni2+, and Mg2+. 相似文献
97.
Osamu Hayashi Haruki Yamada Toshio Miyazaki 《Bioscience, biotechnology, and biochemistry》2013,77(8):1643-1645
The reactions of N-acetylchitooligosaccharides with chitinolytic enzyme were analyzed by HPLC using a Tosoh TSK-Gel amide-80 column with 70% acetonitrile as an eluent. We separated α and β anomeric forms of N-acetylchitooligosaccharides, and obtain the following advantages of this HPLC method.1. We can easily identify the reaction mechanism of chitinolytic enzymes by this method, distinguishing the inverting mechanism showing α anomer formation from the retaining mechanism showing β anomer formation.2. We can also estimate the cleavage patterns of N-acetylchitooligosaccharides by chitinolytic enzymes by using natural substrates. 相似文献
98.
Chiyozo Takayama Osamu Kirino Yoshio Hisada Akira Fujinami 《Bioscience, biotechnology, and biochemistry》2013,77(6):1547-1552
The antifungal activity of 441-acyl derivatives of 3-(3,5-dichlorophenyl)-2,4-imidazol- idinedione against Botrytis cinerea, and of 10 1-sulfonyl compounds against Aiternaria kikuchi- ana were assayed by the agar medium dilution method. The structure-activity relationships for the substituents of the acyl and sulfonyl moieties were analyzed with such physicochemical parameters as hydrophobic π, inductive electronic σ1, and steric E′cs and B1 values by multiple regression. The activity of the acyl derivatives against B. cinerea was related parabolically to the hydrophobicity of the substituents. The stronger the electron-donating power, the larger the overall steric bulkiness, and the smaller the minimum width in the direction perpendicular to the bond axis of the substituents, the greater was the activity. The activity of the sulfonyl derivatives against A. kikuciana was related only to the hydrophobicity of the substituents. 相似文献
99.
Osamu Yamada Akira Kurozumi Fumio Futatsuya Kensaku Ito Shuichi Ishida Katsura Munakata 《Bioscience, biotechnology, and biochemistry》2013,77(7):1467-1471
Some benzophenones substituted with methyl, methoxy, hydroxy or halogen groups inhibited growth and induced chlorosis in various plants. The structure activity relationships about the chlorosis-inducing activity and the growth inhibitory activity of the 3-methyl-benzophenones were well expressed by use of hydrophobic contant π, and Hammett’s σ. The highest selectivity for phytotoxic activities against barnyardgrass and the rice plant was with 3,3′-dimethyl-4-methoxybenzophenone (Methoxyphenone). 相似文献
100.
Tetsu Ando Osamu Saito Koshi Arai Nobutaka Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(11):2643-2649
The female sex pheromone of the oriental corn borer, Ostrinia furnacalis Guenée, was presumed to be composed of (Z)-12-tetradecenyl acetate and its geometrical isomer using electroantennogram technique. From the extracts of female moths, the presence of these compounds in a ratio of ca. 3:2 was confirmed by gas-liquid chromatography and gas-liquid chromatography combined with mass spectrometry in selected ion monitoring mode. Since the male moths were not attracted to mixtures of the two synthetic compounds, the presence of minor component(s) was suggested. 相似文献