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.

我们已经能够建立获得零时间 H+/O 的方法 基于 0.8 秒归零后获得的数据外推的比率 给出不可靠的结果。 这是因为虽然 [H+] vs t 数据， 和 [O] vs t 数据可以通过单指数拟合，两者都不是真正的 单指数特征。 这一发现可能有助于解决一些问题 长期存在的争议是，是否可以通过 当琥珀酸盐为底物时，外推程序为 6.0 或 8.0。 一个 最后一组直接测量 H+/O 的实验和对照 呼吸道位点 III 伴随细胞色素 c 氧化的比率 链通过计算机进行分析。 这些结果早先证实了 在呼吸的前 300 毫秒内突然出现 H+/O 比值的结果 脉冲。 初步实验表明，光散射 可以使用光管和光电管动态记录测量结果 在呼吸脉冲期间，使用线粒体。 这些变化是相关的 线粒体大小和能量状态，并将成为新的基础 系统利用外部离子探针浓度的快速变化来 确定线粒体脉冲期间的 Delta Psi 和 DeltapH 呼吸。 已采取措施开发使用笼式 H+ 和 O2 的系统 化合物引起搅拌溶液中 [H+] 和 [O2] 的阶跃变化。 这将使电极弛豫时间的原位测定成为可能。 用于呼吸脉冲实验的相同搅拌容器。