一种有机金属中间体,在酸酶的基因还原过程中产生
Hong-In Lee1, Robert Y Igarashi, Mikhail Laryukhin
1Department of Chemistry Education, Kyungpook National University, Daegu 702-701, Korea. leehi@knu.ac.kr
Journal of the American Chemical Society
|August 5, 2004
概括
研究人员使用先进的电子核双共振 (ENDOR) 技术研究了一种化酶中间体. 这项研究揭示了被捕获的酶还原中间体的结构,为固定机制提供了洞察力.
科学领域:
- 生物化学 生物化学
- 生物有机化学 生物有机化学
- 酶学 是一种酶学.
背景情况:
- 酶是一种关键的金属酶,催化 (N2) 减少.
- 酶MoFe蛋白中的特定替代改变了基质范围.
- 了解酶中间体是固化的关键.
研究的目的:
- 为了表征一个被困的S = 1/2中介的酶MoFe蛋白在Propargyl酒精减少过程中.
- 通过同位素标记和先进的ENDOR技术,阐明活性位点FeMo辅助因子中间体的结构.
主要方法:
- 酶MoFe蛋白 (alpha-70 Val to Ala) 的位点导向突变发生.
- 制备同位素替代的基醇 ((13) C, (1,2) H).
- 在35 GHz应用连续波 (CW) 和脉冲 (13)C ENDOR,Mims脉冲ENDOR和随机场调制的ENDOR.
主要成果:
- 一个被困的 S = 1/2 周转率中间产品被生成并研究.
- 该中间体含有propargyl酒精的3碳链,由三个质子发出的分辨 (1,2) H ENDOR信号.
- 两个强度合的质子 (H(a)) 呈现相同的超精密张量,限制了结构模型.
- 提出了一种新的生物有机金属复合物,其减少的propargyl酒精产品作为金属cyclopropane与Fe原子结合.
结论:
- 这项研究提供了第一次详细描述被捕获的酶还原中间体.
- 拟议的结构,一个金属-cyclopropane复合体,提供了一个可信的模型基质结合和减少.
- 这项工作促进了对固化的复杂机制的理解.
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