ELECTRON-TRANSFER STUDIES OF COILED-COIL METALLOPROTEINS

卷曲金属蛋白的电子传递研究

• 批准号: 6520225
• 负责人: MICHAEL Y OGAWA
• 金额: $ 13.27万
• 依托单位: BOWLING GREEN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6520225
• 关键词: chemical structure; circular dichroism; covalent bond; electron spin resonance spectroscopy; electron transport; fluorescence resonance energy transfer; gel electrophoresis; high performance liquid chromatography; mass spectrometry; matrix assisted laser desorption ionization; metalloproteins; nuclear magnetic resonance spectroscopy; peptide chemical synthesis; protein structure; pulse radiolysis

DESCRIPTION: (verbatim from applicant's abstract) This proposal seeks to investigate the mechanisms of biological electron-transfer (ET) reactions through the synthesis and study of de novo metalloproteins that have the native-like structure of an alpha-helical coiled-coil. An important feature of these peptides is that they provide the first well-defined model system in which to study the mechanisms of biological ET reactions that occur across a non-covalent peptide-peptide interface. They can also be derivatized to study ET reactions that occur along the covalent backbone of an alpha-helix. A 30-mer polypeptide has recently been prepared and shown to self-assemble into a non-covalent, two-stranded alpha-helical coiled-coil. Metal-based redox centers (i.e. Ru(bpy)(trpy)Im-, and Ru(NH3)5-) were coordinated to histidine residues located at equivalent positions on each of the two peptide chains to prepare the electron-transfer metalloprotein which has been characterized by a number of analytical methods. Pulse radiolysis was used to provide the first observation of an electron-transfer reaction occurring across a non-covalent peptide-peptide interface in a model protein with k(et) = 9600 +- 700 s-1. The experiments described in this proposal will further examine the ET properties of alpha-helical coiled-coils. Studies will be conducted to help determine how, or if, various chemical alterations of the non-covalent peptide interface can influence the rate of electron-transfer. Studies will also be conducted on reactions that occur across a covalently crosslinked interface. Finally, ET reactions will be studied that proceed along the covalent backbone of a single alpha-helical peptide chain. Future results from this work should provide valuable information about the nature of protein-based electron-transfer processes.

描述：（逐字摘自申请人摘要）本提案旨在