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501.
Nishino Hiroshi Hodoki Yoshikuni Thottathil Shoji Devasia Ohbayashi Kako Takao Yoshitake Nakano Shin-ichi 《Aquatic Ecology》2015,49(3):263-272
Aquatic Ecology - Single-cell PCR and gene sequencing were conducted to evaluate species and genotypic compositions of Cryptomonas in the eutrophic Lake Hira, Japan. We determined the sequences of... 相似文献
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Valerie J. Klema Mengyi Ye Aditya Hindupur Tadahisa Teramoto Keerthi Gottipati Radhakrishnan Padmanabhan Kyung H. Choi 《PLoS pathogens》2016,12(2)
Flavivirus nonstructural protein 5 (NS5) consists of methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, which catalyze 5’-RNA capping/methylation and RNA synthesis, respectively, during viral genome replication. Although the crystal structure of flavivirus NS5 is known, no data about the quaternary organization of the functional enzyme are available. We report the crystal structure of dengue virus full-length NS5, where eight molecules of NS5 are arranged as four independent dimers in the crystallographic asymmetric unit. The relative orientation of each monomer within the dimer, as well as the orientations of the MTase and RdRp domains within each monomer, is conserved, suggesting that these structural arrangements represent the biologically relevant conformation and assembly of this multi-functional enzyme. Essential interactions between MTase and RdRp domains are maintained in the NS5 dimer via inter-molecular interactions, providing evidence that flavivirus NS5 can adopt multiple conformations while preserving necessary interactions between the MTase and RdRp domains. Furthermore, many NS5 residues that reduce viral replication are located at either the inter-domain interface within a monomer or at the inter-molecular interface within the dimer. Hence the X-ray structure of NS5 presented here suggests that MTase and RdRp activities could be coordinated as a dimer during viral genome replication. 相似文献
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Yuko Ogawa Yoshihiro Akimoto Mamoru Ikemoto Yoshikuni Goto Anna Ishikawa Sakura Ohta Yumi Takase Hayato Kawakami Masafumi Tsujimoto Ryohei Yanoshita 《Biochemistry and Biophysics Reports》2021
BackgroundExtracellular vesicles (EVs) have been isolated from various sources, including primary and cultured cell lines and body fluids. Previous studies, including those conducted in our laboratory, have reported the stability of EVs under various storage conditions.MethodsEVs from human whole saliva were separated via size-exclusion chromatography. To simulate the effects of gastric or intestinal fluids on the stability of EVs, pepsin or pancreatin was added to the samples. Additionally, to determine the effect of bile acids, sodium cholate was added. The samples were then subjected to western blotting, dynamic light scattering, and transmission electron microscopy analyses. In addition, the activity of dipeptidyl peptidase (DPP) IV retained in the samples was examined to monitor the stability of EVs.ResultsUnder acidic conditions, with pepsin mimicking the milieu of the stomach, the EVs remained stable. However, they partially lost their membrane integrity in the presence of pancreatin and sodium cholate, indicating that they may be destabilized after passing through the duodenum. Although several associated proteins, such as mucin 5B and CD9 were degraded, DPP IV was stable, and its activity was retained under the simulated gastrointestinal conditions.ConclusionOur data indicate that although EVs can pass through the stomach without undergoing significant damage, they may be disrupted in the intestine to release their contents. The consistent delivery of active components such as DPP IV from EVs into the intestine might play a role in the efficient modulation of homeostasis of the signal transduction pathways occurring in the gastrointestinal tract. 相似文献
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Shosuke Okamoto Akiko Hijikata Ryoji Kikumoto Shinji Tonomura Hiroto Hara Kunihiro Ninomiya Akira Maruyama Mamoru Sugano Yoshikuni Tamao 《Biochemical and biophysical research communications》1981,101(2):440-446
Four stereoisomers of 4-methyl-1-[N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulfonyl)-L-arginyl]-2-piperidinecarboxylic acid were synthesized and examined for the inhibitory effect on thrombin. The inhibitory potency varied largely with the stereo-configuration of the 4-methyl-2-piperidinecarboxylic acid portion. The (2R, 4R)-isomer was the most potent inhibitor with a Ki of 0.019 μM, while the (2R, 4S) and (2S, 4R)-isomers showed the values of Ki 0.24 and 1.9 μM, respectively. The least potent inhibitor, (2S, 4S)-isomer, showed a Ki of 280 μM which is approximately 15,000 times that of (2R, 4R)-isomer. 相似文献