ELECTRON-TRANSFER STUDIES OF COILED-COIL METALLOPROTEINS

卷曲金属蛋白的电子传递研究

• 批准号: 6089941
• 负责人: MICHAEL Y OGAWA
• 金额: $ 15.08万
• 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/6089941
• 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：（逐字研究申请人的摘要）该提案试图 研究生物电子转移（ET）反应的机制 通过合成和研究具有的新金属蛋白 α-螺旋线圈的天然状结构。一个重要特征的 这些肽是它们提供了第一个定义明确的模型系统 要研究在一个跨一个 非共价肽肽界面。它们也可以被衍生以研究 ET沿α-螺旋的共价骨架发生的ET反应。 30分钟 多肽最近已经准备好并显示为自我组装 非共价，两链的α-螺旋盘圈。基于金属的氧化还原中心 （即ru（bpy）（trpy）im-和ru（nh3）5-）与组氨酸残基配位 位于两个肽链中的每一个上的等效位置 电子转移金属蛋白的特征是 分析方法。脉冲放射分解用于提供第一个 观察到非共价发生的电子转移反应 具有K（ET）= 9600 +-700 S-1的模型蛋白质中的肽肽界面。这 该提案中描述的实验将进一步研究ET的性质 α-螺旋盘螺旋。将进行研究以帮助确定如何 或者，如果非共价肽界面的各种化学改变可以 影响电子转移的速率。研究也将在 在共价交联的界面上发生的反应。最后，ET 将研究沿着单个的共价骨干进行的反应 α-螺旋肽链。这项工作的未来结果应提供 有关基于蛋白质的电子转移性质的宝贵信息 过程。