一个单位突变 (F429H) 将CYP 2B4酶转化为血红素氧酶:一个QM/MM研究
Dandamudi Usharani1, Costantino Zazza, Wenzhen Lai
1Institute of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
Journal of the American Chemical Society
|February 24, 2012
概括
细胞染色体P450 2B4 (CYP 2B4) 到F429H的突变改变了O-OH键裂变. 突变酶通过同溶性裂变表现出类似血红氧酶的活性,使高效的半氧化成为可能.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 计算化学的计算化学
背景情况:
- 细胞染色体P450 (CYP) 酶对于药物代谢和生物合成至关重要.
- 了解酶失活机制对于药物设计和酶工程至关重要.
- 在CYP 2B4中Phe429对His突变导致正常酶活性丧失.
研究的目的:
- 为了研究在Phe429对His突变时CYP 2B4失活背后的分子机制.
- 为了阐明F429H突变的 (Fe3+) OOH) 中间体中的O-OH键激活途径.
- 了解突变如何赋予CYP 2B4.4的血红氧酶类特征.
主要方法:
- 使用量子力学/分子力学 (QM/MM) 计算.
- 该研究的重点是 (Fe3+) OOH) 中间体的O-OH键激活.
- 进行了对键相互作用和电子结构的分析.
主要成果:
- CYP2B4的F429H突变体表现出同质的O-OH键裂变,与野生类型酶的异质裂变形成鲜明对比.
- His429 形成了额外的 NH---S 键与囊连接体,这与基质的存在一起促进了同解裂变.
- 一个Thr302/水集群有助于基 (OH•) 的定向,以实现高效的中化.
结论:
- 429对His突变从根本上改变了CYP 2B4的催化机制,将其转向同解性O-OH键裂解.
- 突变酶模仿血红氧酶活性,由于特定的键和基质相互作用.
- 这些发现为酶失活和新型生物催化剂的设计提供了洞察力.
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