从酶二化物状态中可逆光诱导的减少消除H2,E(4)(4H) 简斯中间体
Dmitriy Lukoyanov1, Nimesh Khadka2, Zhi-Yong Yang2
1Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
酶酶
科学领域:
- 生物化学
- 生物有机化学
- 酶机制
背景情况:
- 酶催化 (N2) 降解为氨 (NH3),这是生命的重要过程.
- 该机制涉及一系列复杂的减少步骤和中间状态.
- 之前的工作确立了与"Janus中间体" (E4~4H) 相关的每N2的强制性H2释放.
研究的目的:
- 阐明E4 (H) 中介物中还原性消除 (重新) 激活过程的原子级细节.
- 研究H2释放的机制及其与N2结合和减少的关系.
主要方法:
- 在低温 (<20K) 的450nm光分解中介物.
- 电子磁共振 (EPR) 和电子核双共振 (ENDOR) 光谱.
- 运动同位素效应 (KIE) 的测量.
主要成果:
- 通过光诱导的H2释放,E4 (H4) 的光解产生了新的状态,E4 (H2) *.
- 导致H2重新添加 (氧化添加,oa) 来改造E4H.
- 一个大的动态同位素效应 (KIE=10) 和温度不变的量子产量表明核道在H2形成.
结论:
- 在N2降解过程中,Janus中间体 (E4(4H)) 是强制性H2损失的关键阶段.
- 释放H2涉及反应屏障,可能通过核道进行.
- 通过结合N2来维持H2的平衡,从而导致H2的排放和随后的N2的减少.
更多相关视频
10:01Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
07:30A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones
Published on: January 21, 2020
相关概念视频
Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Nucleophilic Aromatic Substitution: Elimination–Addition
Electrophilic Aromatic Substitution: Nitration of Benzene
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Preparation of Amines: Reduction of Amides and Nitriles
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
