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91.
Shigeru Aonuma Tsutomu Mimura Jeman Kim Hiroko Akamatsu Kihachi Saito Masafumi Hisaoka 《Bioscience, biotechnology, and biochemistry》2013,77(10):1377-1380
The products of several Bacillus strains were investigated on rabbit serum calcium decreasing, oxytocic and toad heart function promoting activities. These products were obtained from the clear supernatant fluid of the culture medium after the cells were removed by centrifugation.For the production of rabbit serum calcium decreasing substance, Bacillus subtilis K and Bacillus natto No. 8 were found to be usefull, Bacillus megaterium KM, Bacillus cereus var. mycoides and Bacillus subtilis K produced oxytocic principle. Bacillus subtilis K, Bacillus brevis and Bacillus megaterium KM also produced toad heart function promoting factor.A procedure was developed to obtain the electrophoretically homogenous rabbit serum calcium decreasing substance from culture filtrate of Bacillus subtilis K. The crude substance was obtained as isoelectric precipitate by adjusting the culture filtrate to pH 3.0. The crude substance was purified by gel filtration on a Sephadex G-75 column, isoelectric fractionation and chromatography on DEAE-cellulose column. The purified preparation was shown to be homogenous by Tiselius electrophoresis but was separated into two bands by polyacrylamide electrophoresis. The chemical analysis of this biologically active substance indicated this substance to be a lipoprotein. The substance decreased rabbit serum calcium level about 12% at 6~8hr after intravenous injection (dose; 0.5 mg/kg body weight). 相似文献
92.
Yohei Miyanoiri Mitsuhiro Takeda Kosuke Okuma Akira M. Ono Tsutomu Terauchi Masatsune Kainosho 《Journal of biomolecular NMR》2013,57(3):237-249
The 1H–13C HMQC signals of the 13CH3 moieties of Ile, Leu, and Val residues, in an otherwise deuterated background, exhibit narrow line-widths, and thus are useful for investigating the structures and dynamics of larger proteins. This approach, named methyl TROSY, is economical as compared to laborious methods using chemically synthesized site- and stereo-specifically isotope-labeled amino acids, such as stereo-array isotope labeling amino acids, since moderately priced, commercially available isotope-labeled α-keto acid precursors can be used to prepare the necessary protein samples. The Ile δ1-methyls can be selectively labeled, using isotope-labeled α-ketobutyrates as precursors. However, it is still difficult to prepare a residue-selectively Leu and Val labeled protein, since these residues share a common biosynthetic intermediate, α-ketoisovalerate. Another hindering drawback in using the α-ketoisovalerate precursor is the lack of stereo-selectivity for Leu and Val methyls. Here we present a differential labeling method for Leu and Val residues, using four kinds of stereo-specifically 13CH3-labeled [U–2H;15N]-leucine and -valine, which can be efficiently incorporated into a protein using Escherichia coli cellular expression. The method allows the differential labeling of Leu and Val residues with any combination of stereo-specifically isotope-labeled prochiral methyls. Since relatively small amounts of labeled leucine and valine are required to prepare the NMR samples; i.e., 2 and 10 mg/100 mL of culture for leucine and valine, respectively, with sufficient isotope incorporation efficiency, this approach will be a good alternative to the precursor methods. The feasibility of the method is demonstrated for 82 kDa malate synthase G. 相似文献
93.
Masahiro Moritoki Takeshi Kadowaki Toshiro Niki Daisuke Nakano Genichiro Soma Hirohito Mori Hideki Kobara Tsutomu Masaki Masakazu Kohno Mitsuomi Hirashima 《PloS one》2013,8(4)
Galectin-9 ameliorates various murine autoimmune disease models by regulating T cells and macrophages, although it is not known what role it may have in B cells. The present experiment shows that galectin-9 ameliorates a variety of clinical symptoms, such as proteinuria, arthritis, and hematocrit in MRL/lpr lupus-prone mice. As previously reported, galectin-9 reduces the frequency of Th1, Th17, and activated CD8+ T cells. Although anti-dsDNA antibody was increased in MRL/lpr lupus-prone mice, galectin-9 suppressed anti-dsDNA antibody production, at least partly, by decreasing the number of plasma cells. Galectin-9 seemed to decrease the number of plasma cells by inducing plasma cell apoptosis, and not by suppressing BAFF production. Although about 20% of CD19−/low CD138+ plasma cells expressed Tim-3 in MRL/lpr lupus-prone mice, Tim-3 may not be directly involved in the galectin-9-induced apoptosis, because anti-Tim-3 blocking antibody did not block galectin-9-induced apoptosis. This is the first report of plasma cell apoptosis being induced by galectin-9. Collectively, it is likely that galectin-9 attenuates the clinical severity of MRL lupus-prone mice by regulating T cell function and inducing plasma cell apoptosis. 相似文献
94.
95.
Exposure to high‐concentration oxygen in the neonatal period induces abnormal retinal vascular patterning in mice
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Akane Morita Hiroko Ushikubo Asami Mori Kenji Sakamoto Tsutomu Nakahara 《Birth defects research. Part B, Developmental and reproductive toxicology》2016,107(6):216-224
The interruption of vascular development could cause structural and functional abnormalities in tissues. We have previously reported that short‐term treatment of newborn mice with vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors induces abnormal retinal vascular growth and patterns. An exposure of neonatal mice to high‐concentration oxygen disturbs normal retinal vascular development. The present study aimed to determine (1) whether vascular abnormalities are observed in the retina of newborn mice exposed to high concentrations of oxygen, and (2) how astrocyte network formation is affected following the exposure to hyperoxia. Newborn (postnatal day 0) mice were exposed to 75% oxygen for 48 or 96 hr. During hyperoxia exposure, VEGF expression decreased, and the onset of retinal vascularization was completely suppressed. After completion of the hyperoxic period, retinal vascularization occurred, but it was delayed in a hyperoxic exposure duration‐dependent manner. In retinas of hyperoxia‐exposed mice, dense capillary plexuses were found, and the number of arteries and veins decreased. The astrocyte network formation was slightly delayed under hyperoxic conditions, and the network became denser in retinas of mice with an episode of hyperoxia. Expression of VEGF levels in the avascular retina of mice that were exposed to hyperoxia was higher than that of control mice. These results suggest that short‐term interruption of the onset of vascular development resulting from the reduction in VEGF signals induces abnormal vascular patterns in the mouse retina. The abnormalities in retinal astrocyte behavior might contribute to the formation of an abnormal retinal vascular growth. 相似文献
96.
Ryosuke Fujiwara Shuhei Noda Yoshifumi Kawai Tsutomu Tanaka Akihiko Kondo 《Biotechnology letters》2016,38(9):1543-1549
Objectives
To find a novel host for the production of 4-vinylphenol (4VPh) by screening Streptomyces species.Results
The conversion of p-coumaric acid (pHCA) to 4VPh in Streptomyces mobaraense was evaluated using a medium containing pHCA. S. mobaraense readily assimilated pHCA after 24 h of cultivation to produce 4VPh. A phenolic acid decarboxylase, derived from S. mobaraense (SmPAD), was purified following heterologous expression in Escherichia coli. SmPAD was evaluated under various conditions, and the enzyme’s kcat/Km value was 0.54 mM ?1 s?1. Using intergenetic conjugation, a gene from Rhodobacter sphaeroides encoding a tyrosine ammonia lyase, which catalyzes the conversion of l-tyrosine to p-coumaric acid, was introduced into S. mobaraense. The resulting S. mobaraense transformant produced 273 mg 4VPh l?1 from 10 g glucose l?1.Conclusion
A novel strain suitable for the production of 4VPh and potentially other aromatic compounds was isolated.97.
Yong Wu Fan-Yan Wei Layla Kawarada Takeo Suzuki Kimi Araki Yoshihiro Komohara Atsushi Fujimura Taku Kaitsuka Motohiro Takeya Yuichi Oike Tsutomu Suzuki Kazuhito Tomizawa 《PLoS genetics》2016,12(9)
Reversible infantile liver failure (RILF) is a unique heritable liver disease characterized by acute liver failure followed by spontaneous recovery at an early stage of life. Genetic mutations in MTU1 have been identified in RILF patients. MTU1 is a mitochondrial enzyme that catalyzes the 2-thiolation of 5-taurinomethyl-2-thiouridine (τm5s2U) found in the anticodon of a subset of mitochondrial tRNAs (mt-tRNAs). Although the genetic basis of RILF is clear, the molecular mechanism that drives the pathogenesis remains elusive. We here generated liver-specific knockout of Mtu1 (Mtu1LKO) mice, which exhibited symptoms of liver injury characterized by hepatic inflammation and elevated levels of plasma lactate and AST. Mechanistically, Mtu1 deficiency resulted in a loss of 2-thiolation in mt-tRNAs, which led to a marked impairment of mitochondrial translation. Consequently, Mtu1LKO mice exhibited severe disruption of mitochondrial membrane integrity and a broad decrease in respiratory complex activities in the hepatocytes. Interestingly, mitochondrial dysfunction induced signaling pathways related to mitochondrial proliferation and the suppression of oxidative stress. The present study demonstrates that Mtu1-dependent 2-thiolation of mt-tRNA is indispensable for mitochondrial translation and that Mtu1 deficiency is a primary cause of RILF. In addition, Mtu1 deficiency is associated with multiple cytoprotective pathways that might prevent catastrophic liver failure and assist in the recovery from liver injury. 相似文献
98.
Tsutomu Kataoka Manabu Fuchikami Shinji Nojima Nobuyuki Nagashima Motoaki Araki Jun Omura Tatsuhiro Miyagi Yasumasa Okamoto Shigeru Morinobu 《Genes, Brain & Behavior》2019,18(7)
Impaired fear memory extinction (Ext) is one of the hallmark symptoms of post‐traumatic stress disorder (PTSD). However, since the precise mechanism of impaired Ext remains unknown, effective interventions have not yet been established. Recently, hippocampal‐prefrontal brain‐derived neurotrophic factor (BDNF) activity was shown to be crucial for Ext in naïve rats. We therefore examined whether decreased hippocampal‐prefrontal BDNF activity is also involved in the Ext of rats subjected to a single prolonged stress (SPS) as a model of PTSD. BDNF levels were measured by enzyme‐linked immunosorbent assay (ELISA), and phosphorylation of TrkB was measured by immunohistochemistry in the hippocampus and medial prefrontal cortex (mPFC) of SPS rats. We also examined whether BDNF infusion into the ventral mPFC or hippocampus alleviated the impaired Ext of SPS rats in the contextual fear conditioning paradigm. SPS significantly decreased the levels of BDNF in both the hippocampus and mPFC and TrkB phosphorylation in the ventral mPFC. Infusion of BDNF 24 hours after conditioning in the infralimbic cortex (ILC), but not the prelimbic cortex (PLC) nor hippocampus, alleviated the impairment of Ext. Since amelioration of impaired Ext by BDNF infusion did not occur without extinction training, it seems the two interventions must occur consecutively to alleviate impaired Ext. Additionally, BDNF infusion markedly increased TrkB phosphorylation in the ILC of SPS rats. These findings suggest that decreased BDNF signal transduction might be involved in the impaired Ext of SPS rats, and that activation of the BDNF‐TrkB signal might be a novel therapeutic strategy for the impaired Ext by stress. 相似文献
99.
100.
Chun YJ Shimada T Sanchez-Ponce R Martin MV Lei L Zhao B Kelly SL Waterman MR Lamb DC Guengerich FP 《The Journal of biological chemistry》2007,282(24):17486-17500
Streptomyces and other bacterial actinomycete species produce many important natural products, including the majority of known antibiotics, and cytochrome P450 (P450) enzymes catalyze important biosynthetic steps. Relatively few electron transport pathways to P450s have been characterized in bacteria, particularly streptomycete species. One of the 18 P450s in Streptomyces coelicolor A3(2), P450 105D5, was found to bind fatty acids tightly and form hydroxylated products when electrons were delivered from heterologous systems. The six ferredoxin (Fdx) and four flavoprotein Fdx reductase (FDR) proteins coded by genes in S. coelicolor were expressed in Escherichia coli, purified, and used to characterize the electron transfer pathway. Of the many possibilities, the primary pathway was NADH --> FDR1 --> Fdx4 --> P450 105D5. The genes coding for FDR1, Fdx4, and P450 105D5 are located close together in the S. coelicolor genome. Several fatty acids examined were substrates, including those found in S. coelicolor extracts, and all yielded several products. Mass spectra of the products of lauric acid imply the 8-, 9-, 10-, and 11-hydroxy derivatives. Hydroxylated fatty acids were also detected in vivo in S. coelicolor. Rates of electron transfer between the proteins were measured; all steps were faster than overall hydroxylation and consistent with rates of NADH oxidation. Substrate binding, product release, and oxygen binding were relatively fast in the catalytic cycle; high kinetic deuterium isotope effects for all four lauric acid hydroxylations indicated that the rate of C-H bond breaking is rate-limiting in every case. Thus, an electron transfer pathway to a functional Streptomyces P450 has been established. 相似文献