Electron Transfer in the Cytochrome c - Peroxidases Complex

细胞色素 c - 过氧化物酶复合物中的电子转移

• 批准号: 9121414
• 负责人: James Erman
• 金额: $ 25.5万
• 依托单位: Northern Illinois University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-11-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9121414&HistoricalAwards=false
• 关键词: Electron; Transfer; Cytochrome; Peroxidases; Complex

The cytochrome c-cytochrome c peroxidase (CcP) system provides an exceedingly rich opportunity to investigate the intimate details of protein-protein interactions and long-range electron transfer between physiologically related heme proteins. The objectives of this research proposal lie in two areas. This first area is to characterize the interaction between both horse and yeast iso-1 cytochrome c with yeast CcP. Experiments designed to clarify the stoichiometry of binding between cytochrome c and CcP will be performed to determine if, and under what conditions, more than one cytochrome c may bind to CcP. The high-affinity cytochrome c binding site on CcP will be mapped through site-directed mutagenesis. The role of individual amino acids at the binding site will be assessed through thermodynamic measurements of the binding affinity. The location of any secondary interaction sites will also be determined through site-directed mutagenesis. The second area of interest is to characterize electron transfer between the heme groups of cytochrome c and CcP. Transient-state kinetic techniques will be used to investigate the rate of electron transfer from ferrocytochrome c to the oxidized intermediate of CcP and the rate of redox equilibration between the heme iron and Trp- 191 in CcP compound II. The specificity of the reaction dynamics and the electron transfer pathway will be explored through site- directed mutagenesis of CcP. %%% This work should lead to a better understanding of protein-protein recognition in general, and of heme proteins, which include hemoglobin and the proteins in energy metabolism, in particular

细胞色素c-卵形色素C过氧化物酶（CCP）系统提供了一个极富丰富的机会，可以研究蛋白质 - 蛋白质相互作用的亲密细节和生理相关的血红素蛋白之间的远距离电子转移。 该研究建议的目标在于两个领域。 第一个区域是表征马和酵母ISO-1细胞色素c与酵母CCP之间的相互作用。 将进行旨在阐明细胞色素C和CCP之间结合的化学计量的实验，以确定是否以及在什么条件下，一个以上的细胞色素C可能与CCP结合。 CCP上的高亲和力细胞色素C结合位点将通过位置定向诱变进行映射。 各个氨基酸在结合位点的作用将通过结合亲和力的热力学测量来评估。 任何次级相互作用位点的位置也将通过位置定向的诱变确定。 感兴趣的第二个区域是表征细胞色素C和CCP血红素组之间的电子转移。 瞬态态动力学技术将用于研究从氧化剂CCP的氧化中间体的电子转移速率，以及CCP化合物II中血红素铁和TRP-191之间的氧化还原平衡速率。 反应动力学和电子转移途径的特异性将通过CCP的位置诱变探索。 %%％这项工作应该可以更好地理解蛋白质 - 蛋白质识别，而血红素蛋白质包括血红蛋白和蛋白质，尤其是能量代谢中的蛋白质