蛋白质与蛋白质的相互作用调节了催化和电子转移的方向,在氧化还原酶复合体中
Duncan G G McMillan1, Sophie J Marritt, Mackenzie A Firer-Sherwood
1School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom.
Journal of the American Chemical Society
|June 27, 2013
概括
蛋白与蛋白的相互作用调节了细菌的呼吸. 这是 CymA 酶.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 分子生物学分子生物学
背景情况:
- 蛋白质与蛋白质的相互作用对于调节细胞过程中的酶活性至关重要.
- CymA是一种来自NapC/NirT超级家族的menaquinol-7 (MQ-7) 脱酶,参与了Shewanella oneidensis的呼吸网络.
- 了解 CymA 的功能是解读细菌呼吸机制的关键.
研究的目的:
- 研究蛋白质与蛋白质相互作用在调节 CymA 酶活性中的作用.
- 阐明控制 CymA 催化方向的机制.
- 在S. oneidensis内膜的背景下探索CymA的功能.
主要方法:
- 将CymA纳入固体支膜,模仿细菌的内膜.
- 带有散射的石英晶微平衡 (QCM-D) 来检测CymA-蛋白质复合体的形成.
- 循环电压测量来分析CymA的催化活性和电子转移.
主要成果:
- 在CymA及其氧化还原伙伴,细胞C3 (Fcc3) 之间形成了一个稳定的复合体.
- 单独的CymA降低了MQ-7,但CymA-Fcc3复合物氧化了MQ-7,支持无氧呼吸.
- 蛋白质复合改变了CymA的催化偏差,从还原到氧化.
结论:
- 蛋白与蛋白相互作用,特别是CymA-Fcc3复合,调节了CymA催化的方向.
- 复杂的形成增强了电子转移速率,促进了细菌无氧呼吸.
- 这项研究揭示了细菌多分支呼吸网络中的新型调节机制.
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