基质位置与反应结果的实验相关性在阿利法原酶,SyrB2中的反应结果
Ryan J Martinie1, Jovan Livada1, Wei-chen Chang1
1Departments of †Chemistry and of ‡Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Journal of the American Chemical Society
|May 13, 2015
概括
铁基酸盐依赖的 (Fe/2OG) 氧化酶具有不同的反应性. 基质在铁中心附近的位置决定了SyrB2是酸盐还是酸盐,解释了酶的结果.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
背景情况:
- 铁酸依赖的 (Fe/2OG) 氧化酶进行各种化学反应.
- 在这个酶家族中理解基质特异性和反应结果的确定仍然是一个挑战.
- Fe/2OG基酶SyrB2表现出不同的化和化活性,这取决于氨基酸基质.
研究的目的:
- 研究基质定位如何影响Fe/2OG氧化酶SyrB2.2.的反应结果.
- 为了将基质碳的位置与观察到的化与化相对应.
- 为预测其他Fe/2OG氧酶酶的结果提供一个框架.
主要方法:
- 利用电子磁共振 (EPR) 谱学研究了SyrB2.2的铁-酸添加物.
- 测量了基质原子与铁-酸物种之间的超细合.
- 确定不同氨基酸基质 (l-threonine,l-norvaline,l-aminobutyric acid) 的Fe-(2) H距离和N-Fe-(2) H角.
主要成果:
- 对每个氨基酸的铁中心相对于基质定位建立了不同的几何参数.
- 观察到不同的Fe-(2) H距离 (氨酸的4.2 Å到诺瓦氨酸的3.4 Å) 和N-Fe-(2) H角 (氨酸的85°到诺瓦氨酸的65°).
- 这些几何差异与观察到的反应性趋势 (化与化) 直接相关.
结论:
- 基质的定位是SyrB2.2反应结果的关键决定因素.
- 实验相关性提供了一个基于结构数据的Fe/2OG氧酶活性的预测模型.
- 这项工作有助于理解和预测Fe/2OG酶的催化机制,包括它们在抑制基化或形成中间体中的作用.
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