MAPPING OF ELECTRON TUNNELING PATHWAYS IN PROTEINS

蛋白质中电子隧道路径的绘制

• 批准号: 2883009
• 负责人: DAVID BERATAN
• 金额: $ 15.43万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2883009
• 关键词: chemical models; computer simulation; cytochrome b; cytochrome c; cytochrome c peroxidase; electron transport; enzyme mechanism; molecular dynamics; photosynthetic reaction centers; protein structure; protein structure function; quantum chemistry

Electron tunneling reactions are critical in photosynthesis, oxidative phosphorylation, drug metabolism, biosynthesis, and catalysis. The success or failure or metabolic pathways depends upon the rates of these reactions, which in turn, are controlled by the structure of the medium between electron donor and acceptor. The means by which proteins, nucleic acids, and protein-protein complexes control these reaction rates will be the subject of our investigations (competitive renewal of Grant R01- GM48043). The influence of protein primary, secondary, tertiary, and quaternary structure, protein/protein docking interactions, and protein dynamics on electron transport rates will be probed using new quantitatively reliable methods in the photosynthetic reaction center/cytochrome c/2 complex, cytochrome c peroxidase/cytochrome c complex, cytochrome b/562 and cytochrome c. In addition, new reduced but exact methods of representing the results of protein electron transfer calculations will produce interpretative tools as simple and intuitive as Pathways analysis, but quantitatively reliable. The ubiquitous nature of electron transfer processes in biosynthesis and energy transduction makes them a natural target for investigation. These investigations involve quantum mechanical tunneling of an electron, and tunneling processes display an exquisite sensitivity to the structure of the barrier being traversed. Therefore, if quantitatively understood, these electron tunneling reactions could be used as diagnostics of macromolecule structure (secondary structure in proteins, DNA lesions, etc.) and could be manipulated in a medical setting to control drug metabolism (by cytochrome P/450) or DNA biosynthesis (by ribonucleotide reductase). This research project will be carried out collaboratively between the University of Pittsburgh Department of Chemistry and the University of California, San Diego Department of Physics. This proposal is intended to allow the continuation of collaborative studies that led to the Pathway model of protein electron transfer reactions, related multi- pathway methods, and their numerical implementations.

电子隧穿反应在光合作用、氧化反应、 磷酸化、药物代谢、生物合成和催化。成功 或衰竭或代谢途径取决于这些 而这些反应又受介质结构的控制 电子给体和受体之间。蛋白质、核酸 酸和蛋白质-蛋白质复合物控制这些反应速率， 我们调查的主题（补助金R01的竞争性续期- GM 48043）。蛋白质一级、二级、三级和 四级结构，蛋白质/蛋白质对接相互作用和蛋白质 电子传输速率的动力学将使用新的 光合反应定量可靠的方法 中心/细胞色素c/2复合物，细胞色素c过氧化物酶/细胞色素c 复合物、细胞色素B/562和细胞色素c。此外，新的减少，但 蛋白质电子转移结果的精确表示方法 计算将产生简单直观的解释工具， 路径分析，但定量可靠。 生物合成中电子转移过程的普遍性， 能量转换使它们成为研究的自然目标。这些 研究涉及电子的量子力学隧穿， 隧穿过程显示出对结构的敏感性， 障碍被跨越。因此，如果定量地理解， 这些电子隧穿反应可以被用作 大分子结构（蛋白质的二级结构，DNA损伤， 等等）。并且可以在医疗环境中进行操作以控制药物 代谢（通过细胞色素P/450）或DNA生物合成（通过核糖核苷酸 还原酶）。本研究项目将合作开展 匹兹堡大学化学系和 加州圣地亚哥大学物理系。这项建议 旨在继续进行合作研究， 蛋白质电子转移反应的途径模型，相关的多 路径方法及其数值实现。