CHARGE TRANSFER ACROSS INTERFACES OF BIOLOGICAL SYSTEMS

生物系统界面间的电荷转移

• 批准号: 3273258
• 负责人: DAVID C MAUZERALL
• 金额: $ 14.68万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3273258
• 关键词: bacteriorhodopsins; biological signal transduction; charge transfer complex; chemical reaction; dielectric property; electrochemistry; electron transport; high performance liquid chromatography; ion transport; lasers; mathematics; membrane channels; membrane lipids; membrane model; membrane permeability; membrane potentials; photochemistry; photosynthesis; porphyrins; quinones; thermodynamics

The properties of the lipid bilayer-water interface will be studied by observing the kinetics of photo-generated charge transfer across the interface, of ensuing reverse reaction at that interface and of transmembrane movement of products. Electrical measurements directly probe the charge transfer with subnanosecond time resolution and angstrom (Debye length) distance from the surface. The unique ability of photoreactions to transfer this charge in sub-nanosecond times allows the study of an unprecedented time range, some ten orders of magnitude. The study will be aimed at obtaining information on the electrical and other potentials at the interface, on the molecular motion or viscosity of the interface and on the relaxation of ion atmospheres at these charged interfaces. This information is obtained by detailed analysis of the kinetics of reactions with differently charged or polar lipids and a variety of charged or polar reactants. The transit time of charged species across bilayers will be directly measured in attempts to resolve discrepancies in the literature. These measurements will be applied to the study of charge transfer in modified membrane ion channels, in bacteriorhodopsin and in photosynthetic reaction centers. The aim will be to understand the molecular determinants of the charge transfer by direct measure of the charge movements. New methodologies to measure the thermodynamic properties via kinetically resolved heat formation of photochemical cycles such as occur in phototransduction in rhodopsin, bacteriorhodopsin and photosynthetic reaction centers will be developed. They will be the extension of photoacoustic methodology to the nanosecond time range and the use of a novel method based on changes in ionic conductivity.

将研究脂质双分子层-水界面的性质 通过观察光生电荷转移的动力学 在界面上，在该界面上随后发生的反向反应 以及产品的跨膜运动。电气 测量直接探测电荷转移 亚纳秒时间分辨率和埃(德拜长度) 与曲面的距离。光反应的独特能力 在亚纳秒时间内转移这种电荷允许研究 史无前例的时间范围，大约十个数量级。这个 研究的目的是获得有关电力和电力的信息 界面上的其他势，基于分子运动或 界面粘度与离子气氛的驰豫 在这些带电的界面。此信息通过以下方式获得 详细分析了不同条件下的反应动力学 带电或极性的脂类和各种带电或极性的反应物。 带电物种在双层之间的传输时间将为 直接衡量的是试图解决 文学。这些测量将被应用于研究 修饰膜离子通道中的电荷转移 细菌视紫红质和光合作用反应中心。这个 目的将是了解分子决定因素 通过直接测量电荷运动的电荷转移。 测量热力学性质的新方法 光化学循环的动力学分解热形成 视紫红质、细菌视紫红质和视紫红质的光转导 发展光合作用反应中心。他们将会是 光声方法学向纳秒的延伸 时间范围和一种基于离子变化的新方法的使用 传导性。