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161.
Kotaro Ito Yoshiki Hanya Yasuji Koyama 《Applied microbiology and biotechnology》2013,97(19):8581-8590
Glutaminase, an enzyme that hydrolyzes l-glutamine to l-glutamate, plays an important role in the production of fermented foods by enhancing the umami taste. In this study, we found ten glutaminase genes in the Aspergillus sojae genome by conducting a BLAST search of the characterized glutaminase sequence. We subsequently constructed glutaminase gene disruptants. The glutaminase activity of the gahB disruptant was decreased by approximately 90 % in A. sojae and Aspergillus oryzae, indicating that this enzyme (GahB) accounted for the majority of the glutaminase activity in Aspergillus species. Subsequently, GahB protein was purified from the AsgahB-overexpressing transformant and characterized. The molecular mass was estimated to be approximately 110 and 259 kDa by SDS-PAGE and gel filtration chromatography, respectively, indicating that the native form of AsGahB was a dimer. The optimal pH was 9.0, and the optimal temperature was 50 °C. Analysis of substrate specificity revealed that AsGahB had peptidoglutaminase-asparaginase activity, similar to AsGahA, but preferred free l-glutamine to free l-asparagine, C-terminal glutaminyl, and asparaginyl residues in peptides. 相似文献
162.
Masamitsu Konno Atsushi Hamabe Shinichiro Hasegawa Hisataka Ogawa Takahito Fukusumi Shimpei Nishikawa Katsuya Ohta Yoshihiro Kano Miyuki Ozaki Yuko Noguchi Daisuke Sakai Toshihiro Kudoh Koichi Kawamoto Hidetoshi Eguchi Taroh Satoh Masahiro Tanemura Hiroaki Nagano Yuichiro Doki Masaki Mori Hideshi Ishii 《Development, growth & differentiation》2013,55(3):309-318
Adipose tissue‐derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β‐cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow‐derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. 相似文献
163.
The invasive alien crayfish Pacifastacus leniusculus is considered harmful to freshwater pearl mussels Margaritifera laevis and M. togakushiensis. It also often colonises mussel habitats in Japan. In order to test the negative effects of alien crayfish on mussels, we evaluated the predation impact of signal crayfish on freshwater pearl mussels in vitro. We tested the relationship between the survival/injury rates of mussels and crayfish predation with respect to different sizes of mussels (four classes based on shell length: 10, 30, 50 and 70 mm). Crayfish selectively fed on the flesh of the 10-mm size class mussels after breaking their shells. The shell margins of mussels in all size classes were injured by crayfish. Results also showed that crayfish particularly injured the 50-mm size class of mussels. This observation could be attributed to this mussel size being the most suitable shell size (29.56–37.73 mm in carapace length) that the crayfish can effectively hold. This study shows that the presence of invasive crayfish reduces freshwater pearl mussel populations by damaging the shell margins and/or killing the mussels. This negative impact of invasive crayfish not only decreases the mussel population but could also limit mussel recruitment, growth and reproduction. 相似文献
164.
Yoshihiro Kato Motoji Kawasaki Tomohiro Nigo Shunya Nakamura Akira Fusano Yasuhiro Teranishi Mari N. Ito Takaaki Sumiyoshi 《Bioorganic & medicinal chemistry》2013,21(18):5851-5854
A series of 2,3-disubstituted pyridines were synthesized and evaluated for their PDE4 inhibitory activity. We successfully modified undesirable cyano group of initial lead compound 2 to 4-pyridyl group with improvement of in vitro efficacy and optimized the position of nitrogen atoms in pyridine moiety and alkylene linker. The most potent compound showed significant efficacy in animal models of asthma and inflammation. 相似文献
165.
Keisuke Yoshikawa Yoshihiro Kita Ayako Furukawa Noriko Kawamura Sanae Hasegawa-Ishii Yoichi Chiba Shiro Takei Kei Maruyama Takao Shimizu Atsuyoshi Shimada 《Prostaglandins, leukotrienes, and essential fatty acids》2013,88(5):373-381
Excitotoxicity is involved in neurodegenerative conditions. We investigated the pathological significance of a surge in prostaglandin production immediately after kainic acid (KA) administration [initial phase], followed by a sustained moderate elevation in prostaglandin level [late phase] in the hippocampus of juvenile rats. Numerous pyknotic hippocampal neurons were observed 72 h after KA treatment; this number remained elevated on days 10 and 30. Gross hippocampal atrophy was observed on days 10 and 30. Pre-treatment with indomethacin ameliorated neuronal death on days 10 and 30, and prevented hippocampal atrophy on day 30. Microglial response was moderated by the indomethacin pre-treatment. Blockade of only late-phase prostaglandin production by post-treatment with indomethacin ameliorated neuronal death on day 30. These findings suggest a role for initial-phase prostaglandin production in chronic progressive neuronal death, which is exacerbated by late-phase prostaglandin production. Blockade of prostaglandin production has therapeutic implications in preventing long-term neurological sequelae following excitotoxic brain damage. 相似文献
166.
Shiro Chihara Akira Ito Masahiro Yahata Takashi Tobita Yasuo Koyama 《Bioscience, biotechnology, and biochemistry》2013,77(12):2709-2717
Eight α-N-acyl colistin nonapeptide derivatives including three aliphatic, four aromatic and one alicyclic derivatives were synthesized by the reaction of colistin nonapeptide with corresponding acid chlorides. This acylation reaction was carried out under the condition kept restrictedly at pH 5,0 in order to introduce an acyl group only to α-amino group but not to γ-amino group existing in a colistin nonapeptide molecule. Synthetic method and several physico-chemical natures of these acyl colistin nonapeptide derivatives are given in this paper.All of the acylated derivatives thus synthesized exhibited characteristic antimicrobial activities. Antimicrobial spectra were substantially based upon a gram-negative type and not so much altered by chemical structures of acyl groups which were considerably differentiated from each other such as cyclic or chain form. Thus, more possible response of carbon size than its structure to the antimicrobial effectiveness was inferred. In spite of almost no toxicity and feeble antimicrobial activity of colistin nonapeptide itself, these acylated colistin nonapeptide derivatives showed a toxicity against mice at a dose of 16.9~70 mg/kg in LD50, which, however, was inferior to the toxicity of colistin sulfate, possibly correspondent to their much weaker antimicrobial activities, as a whole. Hence, it seems likely that acyl part of these acylated colistin nonapeptide derivatives including that of colistin is seriously responsible for the biological activities. 相似文献
167.
Hiroyasu Koyama Katsura Kogure Kenji Mori Masanao Matsui 《Bioscience, biotechnology, and biochemistry》2013,77(4):915-920
Antimycinone A3, which is a neutral fragment of mild alkaline hydrolysate of antimycin A3, and its stereoisomers were synthesized stereoselectively from methyl trans-2-n-butylpent-3-enoate or methyl cis-2-n-butylpent-3-enoate, and natural antimycinone A3 was proved to possess Hα-Hβ and Hβ-Hγ trans configuration. 相似文献
168.
169.
170.
Kazumoto Hashizume Kinji Kakiuchi Emiko Koyama Tokuji Watanabe 《Bioscience, biotechnology, and biochemistry》2013,77(4):449-459
When a solution of soybean acid-precipitated or 11S protein was frozen and stored at ?1 to ?5°C, the protein became partially insoluble after thawing. Ultracentrifugation and disc-electrophoresis of freeze-stored 11S protein solution after removing insoluble components revealed that new components which may be aggregates or associates of the 11S component were formed. When concentrated and stored at 5°C, disc-electrophoresis of 11S component showed that associates were formed. Mercaptoethanol could dissolve the insoluble protein and also convert the associates to the original 11S component. NEM–11S was not insolubilized by frozen storage at ?5°C or storage at 5°C after being concentrated. From these facts it can be concluded that denaturation of soybean protein by freezing may be caused by intermolecular reactions through S-S bonds as a result of concentration by freezing. This may suggest a mechanism of the formation of sponge-like texture in kori-tofu which is made by frozen storage of soybean curd for 15 to 20 days at ?1 to ?3°C. 相似文献