从化酶Fe蛋白转移到MoFe蛋白的电子转移的合规门
Karamatullah Danyal1, Diana Mayweather, Dennis R Dean
1Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, USA.
Journal of the American Chemical Society
|May 1, 2010
概括
酶Fe蛋白质电子转移是受形状变化而不是粘度的限制. 透压力揭示了这种封闭机制,水分子在这个过程中发挥了关键作用.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 生物能源学 生物能源学
背景情况:
- 酶Fe蛋白 ([4Fe-4S]集群) 将电子转移到MoFe蛋白中.
- 电子转移 (ET) 与ATP水解相结合.
- 化酶复合体的形状变化表明ET的"入门".
研究的目的:
- 为了研究酸酶中电子转移的"关口假说".
- 了解构造变化在内部复杂电子转移中的作用.
- 为了阐明电子转移和ATP水解之间的关系.
主要方法:
- 研究了Fe (红色) 蛋白质由MoFe蛋白质进行的复合内氧化.
- 利用各种溶液来探测形状控制.
- 测量了透压和粘度效应.
- 评估溶剂运动同位素效应.
主要成果:
- 电子转移门是通过对奥斯莫斯压力变化的反应来确认的.
- 不少于80个水分子参与了反应.
- 粘度变化没有影响电子转移速率.
- 溶剂动态同位素效应的缺失表明ATP水解并没有限制ET的速度.
结论:
- 由透压和水相互作用调节的形状变化,酸酶中门电子转移.
- 电子转移先于ATP水解和Pi释放,解这些事件.
- ATP水解与电子转移的合机制仍然很复杂.
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