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排序方式: 共有206条查询结果,搜索用时 31 毫秒
91.
92.
Norifumi Shioda Yasushi Yabuki Yuka Kobayashi Misaki Onozato Yuji Owada Kohji Fukunaga 《The Journal of biological chemistry》2014,289(27):18957-18965
α-Synuclein (αSyn) accumulation in dopaminergic (DA) neurons is partly regulated by long-chain polyunsaturated fatty acids. We found that fatty acid-binding protein 3 (FABP3, H-FABP), a factor critical for arachidonic acid (AA) transport and metabolism in brain, is highly expressed in DA neurons. Fabp3 knock-out (Fabp3−/−) mice were resistant to 1-methyl-1,2,3,6-tetrahydropiridine-induced DA neurodegeneration in the substantia nigra pars compacta and showed improved motor function. Interestingly, FABP3 interacted with αSyn in the substantia nigra pars compacta, and αSyn accumulation following 1-methyl-1,2,3,6-tetrahydropiridine treatment was attenuated in Fabp3−/− compared with wild-type mice. We confirmed that FABP3 overexpression aggravates AA-induced αSyn oligomerization and promotes cell death in PC12 cells, whereas overexpression of a mutant form of FABP3 lacking fatty-acid binding capacity did not. Taken together, αSyn oligomerization in DA neurons is likely aggravated by AA through FABP3 in Parkinson disease pathology. 相似文献
93.
94.
Tatsuya Ueki Norifumi Kawakami Masaaki Toshishige Koichi Matsuo Kunihiko Gekko Hitoshi Michibata 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Background
Vanabins are a unique protein family of vanadium-binding proteins with nine disulfide bonds. Possible binding sites for VO2+ in Vanabin2 from a vanadium-rich ascidian Ascidia sydneiensis samea have been detected by nuclear magnetic resonance study, but the metal selectivity and metal-binding ability of each site was not examined.Methods
In order to reveal functional contribution of each binding site, we prepared several mutants of Vanabin2 by in vitro site-directed mutagenesis and analyzed their metal selectivity and affinity by immobilized metal-ion affinity chromatography and Hummel Dreyer method.Results
Mutation at K10/R60 (site 1) markedly reduced the affinity for VO2+. Mutation at K24/K38/R41/R42 (site 2) decreased the maximum binding number, but only slightly increased the overall affinity for VO2+. Secondary structure of both mutants was the same as that of the wild type as assessed by circular dichroism spectroscopy. Mutation in disulfide bonds near the site 1 did not affect its high affinity binding capacity, while those near the site 2 decreased the overall affinity for VO2+.General significance
These results suggested that the site 1 is a high affinity binding site for VO2+, while the site 2 composes a moderate affinity site for multiple VO2+. 相似文献95.
Ikeda K Ikawa K Ikeda A Nishikawa Y Morikawa N 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2006,844(1):148-152
A simple, rapid and precise HPLC method using ultrafiltration to remove plasma protein was developed to determine biapenem concentrations in human plasma. Plasma was separated by centrifugation at 4 degrees C from blood collected in heparinized vacuum tubes, and biapenem was stabilized by immediate mixing the plasma with 1M 3-morpholinopropanesulfonic acid (MOPS) buffer (pH 7.0) (1:1). Biapenem was detected by ultraviolet absorbance at 300nm with no interfering plasma peak. The calibration curve of biapenem in human plasma was linear from 0.04 to 50microg/mL. The limit of detection was 0.01microg/mL, which was more than 40-fold lower than that of conventional plasma protein precipitation using ammonium sulfate. The assay has been clinically applied to pharmacokinetic studies in patients. 相似文献
96.
97.
Shigeki Moriguchi† Feng Han§ Norifumi Shioda Yui Yamamoto Takeharu Nakajima‡ Osamu Nakagawasai‡ Takeshi Tadano‡ Jay Z. Yeh† Toshio Narahashi† Kohji Fukunaga¶ 《Journal of neurochemistry》2009,110(1):170-181
Aberrant behaviors related to learning and memory in olfactory bulbectomized (OBX) mice have been documented in the previous studies. We reported that the impairment of long-term potentiation (LTP) of hippocampal CA1 regions from OBX mice was associated with down-regulation of CaM kinase II (CaMKII) and protein kinase C (PKC) activities. We now demonstrated that the nootropic drug, nefiracetam, significantly improved spatial reference memory-related behaviors as assessed by Y-maze and novel object recognition task in OBX mice. Nefiracetam also restored hippocampal LTP injured in OBX mice. Nefiracetam treatment restored LTP-induced PKCα (Ser657) and NR1 (Ser896) phosphorylation as well as increase in their basal phosphorylation in the hippocampal CA1 region of OBX mice. Likewise, nefiracetam improved LTP-induced CaMKIIα (Thr286) autophosphorylation and GluR1 (Ser831) phosphorylation and increased their basal phosphorylation. The enhancement of PKCα (Ser657) and CaMKIIα (Thr286) autophosphorylation by nefiracetam was inhibited by treatment with (±)-α-Methyl-(4-carboxyphenyl)glycine and DL-2-Amino-5-phosphonovaleric acid, respectively. The enhancement of LTP induced by nefiracetam is inhibited by treatment with 2-methyl-6-(phenylethynyl)-pyridine, but not by treatment with LY367385, suggesting that metabotropic glutamate receptor 5 (mGluR5) but not mGluR1 is involved in the nefiracetam-induced LTP enhancement. Taken together, nefiracetam ameliorates OBX-induced deficits in memory-related behaviors and impairment of LTP in the hippocampal CA1 region through activation of NMDAR and mGluR5, thereby leading to an increase in activities of CaMKIIα (Thr286) and PKCα (Ser657), respectively. 相似文献
98.
During left-right (L-R) axis formation, Nodal is expressed in the node and has a central role in the transfer of L-R information in the vertebrate embryo. Bone morphogenetic protein (BMP) signaling also has an important role for maintenance of gene expression around the node. Several members of the Cerberus/Dan family act on L-R patterning by regulating activity of the transforming growth factor-β (TGF-β) family. We demonstrate here that chicken Dan plays a critical role in L-R axis formation. Chicken Dan is expressed in the left side of the node shortly after left-handed Shh expression and before the appearance of asymmetrically expressed genes in the lateral plate mesoderm (LPM). In vitro experiments revealed that DAN inhibited BMP signaling but not NODAL signaling. SHH had a positive regulatory effect on Dan expression while BMP4 had a negative effect. Using overexpression and RNA interference-mediated knockdown strategies, we demonstrate that Dan is indispensable for Nodal expression in the LPM and for Lefty-1 expression in the notochord. In the perinodal region, expression of Dan and Nodal was independent of each other. Nodal up-regulation by DAN required NODAL signaling, suggesting that DAN might act synergistically with NODAL. Our data indicate that Dan plays an essential role in the establishment of the L-R axis by inhibiting BMP signaling around the node. 相似文献
99.
Miki Kawada-Matsuo Yuuma Yoshida Takeshi Zendo Junichi Nagao Yuichi Oogai Yasunori Nakamura Kenji Sonomoto Norifumi Nakamura Hitoshi Komatsuzawa 《PloS one》2013,8(7)
Staphylococcus aureus uses two-component systems (TCSs) to adapt to stressful environmental conditions. To colonize a host, S. aureus must resist bacteriocins produced by commensal bacteria. In a comprehensive analysis using individual TCS inactivation mutants, the inactivation of two TCSs, graRS and braRS, significantly increased the susceptibility to the class I bacteriocins, nukacin ISK-1 and nisin A, and inactivation of vraSR slightly increased the susceptibility to nukacin ISK-1. In addition, two ABC transporters (BraAB and VraDE) regulated by BraRS and one transporter (VraFG) regulated by GraRS were associated with resistance to nukacin ISK-1 and nisin A. We investigated the role of these three TCSs of S. aureus in co-culture with S. warneri, which produces nukacin ISK-1, and Lactococcus lactis, which produces nisin A. When co-cultured with S. warneri or L. lactis, the braRS mutant showed a significant decrease in its population compared with the wild-type, whereas the graRS and vraSR mutants showed slight decreases. Expression of vraDE was elevated significantly in S. aureus co-cultured with nisin A/nukacin ISK-1-producing strains. These results suggest that three distinct TCSs are involved in the resistance to nisin A and nukacin ISK-1. Additionally, braRS and its related transporters played a central role in S. aureus survival in co-culture with the strains producing nisin A and nukacin ISK-1. 相似文献
100.
Norifumi Urao Varadarajan Sudhahar Seok-Jo Kim Gin-Fu Chen Ronald D. McKinney Georg Kojda Tohru Fukai Masuko Ushio-Fukai 《PloS one》2013,8(3)