QQ客服 官方微博 反馈留言

	Exploring the Electron Transfer Properties of Neuronal Nitric-oxide Synthase by Reversal of the FMN Redox Potential
	Li, H. Y. ; Das, A. ; Sibhatu, H. ; Jamal, J. ; Sligar, S. G. ; Poulos, T. L. ; Li HY(李海燕)
	2008
关键词	OXIDATION-REDUCTION POTENTIALS FLAVOPROTEIN DOMAIN FUNCTIONAL INTERACTIONS FLAVIN MONONUCLEOTIDE BACILLUS-MEGATERIUM OUTPUT STATE CALMODULIN HEME FLAVODOXIN MECHANISM
英文摘要	In nitric-oxide synthase ( NOS) the FMN can exist as the fully oxidized ( ox), the one-electron reduced semiquinone (sq), or the two-electron fully reduced hydroquinone (hq). InNOS and microsomal cytochrome P450 reductase the sq/hq redox potential is lower than that of the ox/sq couple, and hence it is the hq form of FMN that delivers electrons to the heme. Like NOS, cytochrome P450BM3 has the FAD/FMN reductase fused to the C-terminal end of the heme domain, but in P450BM3 the ox/sq and sq/hq redox couples are reversed, so it is the sq that transfers electrons to the heme. This difference is due to an extra Gly residue found in the FMN binding loop in NOS compared with P450BM3. We have deleted residue Gly-810 from the FMN binding loop in neuronal NOS ( nNOS) to give Delta G810 so that the shorter binding loop mimics that in cytochrome P450BM3. As expected, the ox/sq redox potential now is lower than the sq/ hq couple. Delta G810 exhibits lower NO synthase activity but normal levels of cytochrome c reductase activity. However, unlike the wild-type enzyme, the cytochrome c reductase activity of Delta G810 is insensitive to calmodulin binding. In addition, calmodulin binding to Delta G810 does not result in a large increase in FMN fluorescence as in wild-type nNOS. These results indicate that the FMN domain in Delta G810 is locked in a unique conformation that is no longer sensitive to calmodulin binding and resembles the "on" output state of the calmodulin-boundwild-type nNOS with respect to the cytochrome c reduction activity.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/62198]
专题	化学化工－已发表论文
推荐引用方式 GB/T 7714	Li, H. Y.,Das, A.,Sibhatu, H.,et al. Exploring the Electron Transfer Properties of Neuronal Nitric-oxide Synthase by Reversal of the FMN Redox Potential[J],2008.
APA	Li, H. Y..,Das, A..,Sibhatu, H..,Jamal, J..,Sligar, S. G..,...&李海燕.(2008).Exploring the Electron Transfer Properties of Neuronal Nitric-oxide Synthase by Reversal of the FMN Redox Potential..
MLA	Li, H. Y.,et al."Exploring the Electron Transfer Properties of Neuronal Nitric-oxide Synthase by Reversal of the FMN Redox Potential".(2008).

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。