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硫化对含有Ni的一氧化碳脱的作用
1Department of Chemistry, Texas A&M University, College Station, 77843-3255, USA.
Journal of the American Chemical Society
|July 22, 2004
概括
硫化物离子通过可逆地与酶结合来抑制一氧化碳脱酶 (CODH) 的活性.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 生物有机化学 生物有机化学
背景情况:
- 一氧化碳脱酶 (CODH) 对于碳循环至关重要.
- 活性位点C集群结构在CODH酶之间有所不同.
- 一个关键的区别是Carboxydothermus hydrogenoformans CODH中存在一个mu(2) - 硫化离子,而Rhodospirillum rubrum (CODH(Rr)) 和Moorella thermoacetica (CODH(Mt)) CODH中没有这种离子.
研究的目的:
- 调查CODH活跃地点的结构和功能差异.
- 探索硫化物对CODH活性和光谱特性的影响.
主要方法:
- 酶活性测定. 酶活性测定.
- 电子偏磁共振 (EPR) 光谱学.电子偏磁共振 (EPR) 光谱学.
- 动力分析以确定抑制常量 (K(I)).
主要成果:
- 硫化物部分抑制了CODH (Rr) 和CODH (Mt) 的CO氧化活性,导致CODH (Rr) 的滞后.
- 硫化物与CODH ((Mt) 在C ((red1) 状态的结合改变了EPR信号,并且是可逆的.
- 一个运动模型提出可逆的硫化物与C ((red1) 结合,抑制催化并在减少时解离.
结论:
- 硫化物可逆抑制CODH活动,通过结合C(red1) 状态.
- 硫化物的抑制作用与其他离子相似,表明一种共同的结合方式.
- 这种结合可能涉及C中的Ni和独特Fe原子的桥梁.
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