STRUCTURE OF CYTOCHROME P450 REDOX PARTNER COMPLEXES

细胞色素 P450 氧化还原伙伴复合物的结构

• 批准号: 6018443
• 负责人: Irina F Sevrioukova
• 金额: $ 3.68万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6018443
• 关键词: X ray crystallography; crystallization; cytochrome P450; enzyme complex; enzyme mechanism; enzyme structure; flavin mononucleotide; isozymes; oxidoreductase

Interaction of the P450 enzymes with their redox partners and the mechanism of electron transfer are the most important and intriguing problems in the area of P450 research. The crystal structures of four bacterial P450s, the catalytical domain of microsomal P450 reductase, and the NMR structure of putidaredoxin are known. However, knowledge of these structures does not directly answer where and how the proteins interact. Since interaction of other electron transfer proteins in crystallographic electron transfer complexes was shown to be specific and relevant to that occurring in a solution, we propose that crystallization of P450-redox partner complexes will enable the identification of interaction sites, conformation changes occurring upon binding, and the electron pathway from one co-factor to another. The P450cam electron transfer system and the heme/FMN-binding domain of flavocytochrome P450BM-3, a functional and structural analog to microsomal P450s and reductase, are the best candidates for crystallization trials of Class I and Class II monooxygenase systems, respectively. Having crystallized both the covalently linked heme/FMN-binding domain and the non-covalent complex between the separate heme-and FMN-binding domains of P450BM-3, we are in an excellent position to solve these structures, which will, undoubtedly, lead to our better understanding of the mechanism and function of microsomal P450-dependent monooxygenase systems.

P450 酶与其氧化还原伙伴以及 电子转移机制是最重要和最有趣的 P450研究领域的问题。四种晶体结构 细菌 P450、微粒体 P450 还原酶的催化结构域，以及 恶臭氧还蛋白的NMR结构是已知的。然而，了解这些 结构并不能直接回答蛋白质相互作用的位置和方式。 由于晶体学中其他电子转移蛋白的相互作用 电子转移复合物被证明是特定的并且与之相关 发生在溶液中，我们建议 P450-氧化还原的结晶 合作伙伴复合体将能够识别交互站点， 结合时发生构象变化，以及电子途径 一个辅助因子是另一个辅助因子。 P450cam 电子传输系统和 黄素细胞色素 P450BM-3 的血红素/FMN 结合域，一种功能性和 微粒体 P450 和还原酶的结构类似物是最好的 I类和II类结晶试验候选者 分别是单加氧酶系统。 共价连接的血红素/FMN 结合结构域和 单独的血红素和 FMN 结合域之间的非共价复合物 P450BM-3，我们处于解决这些结构的绝佳位置， 毫无疑问，这将使我们更好地理解该机制 和微粒体 P450 依赖性单加氧酶系统的功能。