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91.
Yoshiaki Suzuki Hisao Yamamura Susumu Ohya Yuji Imaizumi 《The Journal of biological chemistry》2013,288(51):36750-36761
L-type voltage-dependent Ca2+ channels (LVDCC) and large conductance Ca2+-activated K+ channels (BKCa) are the major factors defining membrane excitability in vascular smooth muscle cells (VSMCs). The Ca2+ release from sarcoplasmic reticulum through ryanodine receptor significantly contributes to BKCa activation in VSMCs. In this study direct coupling between LVDCC (Cav1.2) and BKCa and the role of caveoline-1 on their interaction in mouse mesenteric artery SMCs were examined. The direct activation of BKCa by Ca2+ influx through coupling LVDCC was demonstrated by patch clamp recordings in freshly isolated VSMCs. Using total internal reflection fluorescence microscopy, it was found that a large part of yellow fluorescent protein-tagged BKCa co-localized with the cyan fluorescent protein-tagged Cav1.2 expressed in the plasma membrane of primary cultured mouse VSMCs and that the two molecules often exhibited FRET. It is notable that each BKα subunit of a tetramer in BKCa can directly interact with Cav1.2 and promotes Cav1.2 cluster in the molecular complex. Furthermore, caveolin-1 deficiency in knock-out (KO) mice significantly reduced not only the direct coupling between BKCa and Cav1.2 but also the functional coupling between BKCa and ryanodine receptor in VSMCs. The measurement of single cell shortening by 40 mm K+ revealed enhanced contractility in VSMCs from KO mice than wild type. Taken together, caveolin-1 facilitates the accumulation/clustering of BKCa-LVDCC complex in caveolae, which effectively regulates spatiotemporal Ca2+ dynamics including the negative feedback, to control the arterial excitability and contractility. 相似文献
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95.
Yoshiaki Kitamura Yuki Masegi Shunsuke Ogawa Remi Nakashima Yukihiro Akao Yoshihito Ueno Yukio Kitade 《Bioorganic & medicinal chemistry》2013,21(15):4494-4501
We have developed chemically modified siRNAs and miRNAs bearing urea/thiourea-bridged aromatic compounds at their 3′-end for RNAi therapy. Chemically modified RNAs possessing urea/thiourea-bridged aromatic compounds instead of naturally occurring dinucleotides at the 3′-overhang region were easily prepared in good yields and were more resistant to nucleolytic hydrolysis than unmodified RNA. siRNAs containing urea or thiourea derivatives showed the desired knockdown effect. Furthermore, modified miR-143 duplexes carrying the urea/thiourea compounds in the 3′-end of each strand were able to inhibit the growth of human bladder cancer T24 cells. 相似文献
96.
Humio Kurasawa Yoshiaki Kanauti Koji Takei Shiroshi Ogawa Tetsutaro Okabe Toshiro Hayakawa 《Bioscience, biotechnology, and biochemistry》2013,77(10):1809-1813
A screening was designed to isolate microorganisms having poly(γ-glutamic acid) (PGA) endohydrolase activity. Of the strains screened, TM-4222, from a soil sample, showed the highest viscosity decrement ability on PGA. It was identified to be a Myrothecium sp. The fungal production of the enzyme was slightly promoted with yeast extract and greatly promoted with· both yeast extract and PGA. The fungus was evaluated to produce PGA hydrolase of an endo-type specificity by analyzing of the reaction products. 相似文献
97.
Humio Kurasawa Yoshiaki Kanauchi Tadakatsu Wakayama Toshiro Hayakawa Ikuo Igaue 《Bioscience, biotechnology, and biochemistry》2013,77(12):2913-2916
Varoius piericidin analogues (PS-I, -II and -III in Fig. 2) were synthesized from three 4-acetoxy-6-formylpyridines by Wittig reaction to determine the structure-activity relationships. New type inhibitors, 5-alkenyl-2, 3-dimethoxy-4-hydroxy-6-methylpyridines (PS-IV) were synthesized by intramolecular cyclization. 相似文献
98.
Norihiro Azuma Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(9):2655-2660
Human casein micelles were reconstituted from isolated κ- and β-caseins and calcium ions. Micelle formation was recognized in the presence of calcium chloride even at the low concentration of 5mM. At pH levels ranging from 5.5 to 8.0, the re-formed micelles were quite stable so that precipitation of β-casein was not observed. The large micelles were constituted by a higher ratio of β-casein to κ-casein (16:1 by weight) than the small micelles (3: 1). The κ-casein in the small micelles contained carbohydrates to about 43% (w/w) in the molecule, whereas that in the large micelles was only about 25%. When the casein micelles were re-formed from κ-easein and fractionated β-casein components, the extent of phosphorylation of the β-casein component was found to influence the micelle formation; i.e., the β-casein component with no phosphate (the 0-P form) was disadvantageous to form micelles, but the component with 5 phosphates (the 5-P form) formed micelles most easily. 相似文献
99.
Makoto Kiso Hisao Nishiguchi Akira Hasegawa Hiroyuki Okumura Ichiro Azuma 《Bioscience, biotechnology, and biochemistry》2013,77(6):1523-1525
In the initial stage of hydrolysis, exo-ß-(l-→3)-d-glucanase from Basidiomycetes sp. QM 806 cleaved laminaran from Eisenia bicyclis with a pattern resembling an endo-hydrolase. Five kinds of intermediate gluco-oligosaccharides were separated by a combination of gel filtration and HPLC. They were shown to be 32-O-ß-d-glucosyl-gentiobiose, 32-O-ß-d-gentiobiosyl-gentiobiose, 33O-ß-d-glucosyl-gentiotriose, 34-ß-d-glucosyl-32-O-gentiobiosyl-gentiobiose, and 33-O-ß-d-gentio-biosylgentiotriose by enzymic hydrolysis and methylation analysis as well as by 13C NMR spectroscopy. As a result, such kinds of ß-(l → 3)-ß-(l→6)-linked oligosaccharides could be accounted for in the initial cleavage, and they were hydrolyzed ultimately to glucose, gentiobiose, and gentio-triose. It suggests that a single (1 → 3)-linkage on a block of (1 → 6)-links show some resistance to attack by this enzyme. 相似文献
100.
Yoshiaki Nakahara Masanao Matsui Kenji Mori 《Bioscience, biotechnology, and biochemistry》2013,77(11):2243-2245
A novel synthetic method of 3-substituted furans was developed and syntheses of perillen and dendrolasin are described. 相似文献