KINETIC STUDIES OF PROTON AND ELECTRON FLOWS DURING RESPIRATION

呼吸过程中质子和电子流动的动力学研究

• 批准号: 3966524
• 负责人: R W HENDLER
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3966524
• 关键词: Escherichia coli; acidity /alkalinity; anions; bioenergetics; cations; cellular respiration; electrochemistry; electrodes; electron transport; hydrogen transport; ion transport; ionophores; mathematical model; membrane permeability; membrane potentials; mitochondria; oxygen transport; potassium; radiotracer; salicylate

We have been able to establish that the method of obtaining zero time H+/O ratios based on extrapolation of data obtained after 0.8 s back to zero gives undependable results. This is because although both [H+] vs t data, and [O] vs t data can be fit by single exponentials, neither is truly single exponential in character. This finding might help resolve some of the long standing controversy as to whether the zero-time value obtained by extrapolation procedures is 6.0 or 8.0 when succinate is the substrate. A final group of experiments and controls on the direct measurement of H+/O ratios accompanying cytochrome c oxidation at site III of the respiratory chain were analyzed by computer. These results substantiate earlier findings of a burst of H+/O ratios within the first 300 ms of a respiratory pulse. Preliminary experiments have shown that light scattering measurements can be dynamically recorded with a light pipe and photocell during a respiratory pulse, using mitochondria. These changes are related to mitochondrial size and energy state and will be the basis for a new system using rapid changes in external ion probe concentrations to determine Delta Psi and DeltapH during a pulse in mitochondrial respiration. Steps were taken to develop a system using caged H+ and O2 compounds to cause a step change in [H+] and [O2] in stirred solutions. This will enable the determination of electrode relaxation times in situ in the same stirred vessels used for respiratory pulse experiments.

我们已经能够确定获得零时间H+/O的方法 基于在0.8 s回到零后获得的数据外推的比率 给出不可依赖的结果。 这是因为尽管[H+]与T数据都 [o] vs t数据可以由单个指数拟合，这也不是真正的 字符中的单个指数。 这一发现可能有助于解决一些 关于是否通过 当琥珀酸酯是底物时，外推过程为6.0或8.0。 一个 最终的实验和对照H+/O的直接测量 伴随呼吸部位点III的细胞色素C氧化的比率 通过计算机分析链。 这些结果证实了 呼吸的前300毫秒内H+/O比的发现 脉冲。 初步实验表明光散射 可以用轻管和光电器动态记录测量值 在呼吸脉冲期间，使用线粒体。 这些变化与 线粒体大小和能量状态，将成为新的基础 系统使用外部离子探针浓度快速变化 在线粒体中的脉冲期间确定三角psi和deltaph 呼吸。 采取了步骤使用笼子H+和O2开发系统 化合物在搅拌溶液中引起[H+]和[O2]的步骤变化。 这将使原位确定电极放松时间 用于呼吸脉冲实验的相同搅拌容器。