亚硝酸盐还原酶催化反应中的多质子耦合电子转移机理的研究
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- 英文论文题名：The Theoretical Study of Multi-Proton-Coupled Electron Transfer during the Catalyzing Process of Nitrite Reductase
- 论文作者：秦鑫 ; 陈效华
- 英文论文作者：Xin Qin ; Xiaohua Chen ; Department of Chemistry and Chemical Engineering ; University of Chongqing
- 年：2016
- 作者机构：重庆大学化学化工学院;
- 论文关键词：含铜亚硝酸盐还原酶 ; 电子转移 ; 三质子转移
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十九分会：化学中的量子与经典动力学
- 语种：中文
- 分类号：O643.31
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十九分会 ; 化学中的量子与经典动力学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：176k
- 原文格式：D
- 会议级别：全国
摘要
亚硝酸盐还原酶催化还原亚硝酸根离子为一氧化氮的反应是脱氮作用中必经的一步,其中涉及一个电子、两个质子的转移~1。含铜亚硝酸盐还原酶中活性位点T2Cu的次级配体天冬氨酸残基及组氨酸残基在质子和电子转移的过程中起到比较重要的作用。计算结果显示,该催化反应雇佣特殊的三质子耦合电子转移的反应机理和双质子耦合NO脱离机理。组氨酸残基和天冬氨酸残基通过一个水分子形成氢键网,在催化反应中,组氨酸残基通过该氢键网将质子传递到天冬氨酸残基,促进天冬氨酸侧链将质子传递到亚硝酸根离子,从而形成一种三质子同时向同一方向运动传递的过程,同时一个电子从T1Cu位点转移到T2Cu位点,使其发生一种特殊的三质子协同电子转移机理。
The catalytic reduction of nitrite to nitric oxide including two protons and an electron transfer is an obligatory step during bacterial denitrification~1. The catalytic T2Cu active site of copper-containing nitrite reductase has two second sphere ligands: Histidine residue and Aspartic acid residue, playing an important role in the proton transfer reactions. Our calculations reveal that the catalytic reactions employ a triple-proton-coupled electron-transfer mechanism and a double-proton-coupled NO abruption mechanism, two special mechanisms. His links to the side chain of Asp by a water molecule, forming a proton transfer pathway for three protons moving together. At the same time, an electron transfers from T1Cu to T2Cu.
The catalytic reduction of nitrite to nitric oxide including two protons and an electron transfer is an obligatory step during bacterial denitrification~1. The catalytic T2Cu active site of copper-containing nitrite reductase has two second sphere ligands: Histidine residue and Aspartic acid residue, playing an important role in the proton transfer reactions. Our calculations reveal that the catalytic reactions employ a triple-proton-coupled electron-transfer mechanism and a double-proton-coupled NO abruption mechanism, two special mechanisms. His links to the side chain of Asp by a water molecule, forming a proton transfer pathway for three protons moving together. At the same time, an electron transfers from T1Cu to T2Cu.
引文
[1]M.J.Boulanger.;M.Kukimoto.;M.E.P.Murphy.J.Biol.Chem.2000,275:23957.