降低活性氧化减少酶与基质直接反应
Jeannine M Chan1, John A Bollinger, Cassidy L Grewell
1Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
Journal of the American Chemical Society
|March 12, 2004
概括
氧化还原酶在其CuZ中心将N2O转化为N2. 这项研究表明,激活的酶结合N2O,揭示了潜在的催化中间状态.
科学领域:
- 生物化学 生物化学
- 微生物学 微生物学
- 酶学 是一种酶学.
背景情况:
- 细菌脱转化转化氧化,氧化减少酶 (N2OR) 催化最终的N2O转化为N2.
- 酶的活性部位,4-硫化物桥梁四核CuZ中心,对于这种反应至关重要.
研究的目的:
- 调查来自Achromobacter环状细胞的N2OR的基质相互作用和催化机制.
- 描述激活酶中的CuZ中心的氧化状态.
主要方法:
- 降低活性N2OR的分离和表征.
- 可见吸收和电子磁共振 (EPR) 谱学.
- 用15N标记的N2O进行酶试验.
主要成果:
- 甲基维奥基因的还原激活增加了N2OR特异性活性高达15倍.
- 光谱分析证实CuZ中心可以达到 [4Cu(I) ] 的氧化状态.
- 在添加N2O和检测标记产品时的光谱变化表明了基质相互作用和潜在的催化中间体.
结论:
- 激活的N2OR与N2O结合,这表明在稳定状态周转之前存在基质相互作用阶段.
- 在970nm处的新型吸收带可能意味着N2O减少中的关键催化中间体.
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