POTENTIOMETRIC STUDIES OF RESPIRATORY COMPONENTS OF E COLI AND MITOCHONDRIA

大肠杆菌和线粒体呼吸成分的电位研究

• 批准号: 4694476
• 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/4694476
• 关键词: Escherichia coli; bioenergetics; biomedical automation; cell biology; cell membrane; cellular respiration; cytochrome b; cytochrome oxidase; cytochromes; electron transport; heart cell; hydrogen transport; liver cells; mathematical model; mitochondria; oxidation reduction reaction; potentiometry

Using procedures developed in this laboratory for the acquistion and analysis of more data than is normally processed for spectral potentiometric studies, we have completed the analysis of cytochrome aa-3 in intact mitochondria and in isolation. Our analyses support the following unique new characteristics for the enzyme. (1) There are three Nernstian components. (2) The Em values are 200 mV, 260 mV, and 340 mV with corresponding n values of 2, 2, and l. (3) The individual absorption maxima for the Soret and Alpha peaks are 429 and 602 nm; 446, and 605 nm; and 448 and 607 nm, respectively. (4) Cytochrome a-3 is the component with Soret maximum of 429 nm and Aplpha at 602 nm. (5) The redox potential of heme a-3 is under the control of the redox state of heme a; it is 200 mV when heme a is reduced and greater than 420 mV when heme a is oxidized. (6) The Em of heme a-3 is not raised in an atmosphere of carbon monoxide and this behavior indicates that protons are held less strongly by the reduced liganded enzyme than the oxidized form. The general result of our studies with all of the mitochondrial cytochromes is that the electron transport chain passes 2 electrons at a time rather than one. This conclusion is consistent with a number of other observations. We have analyzed earlier methods of data acquistion and analysis and have found that they are not capable of resolving the mixture and character of cytochromes revealed by our methods.

使用本实验室开发的程序来获取和 分析比通常处理光谱更多的数据 电位研究，我们完成了细胞色素aa-3的分析 在完整的线粒体中并分离。 我们的分析支持 遵循酶独特的新特性。 (1)共有三个 能斯特分量。 (2) Em 值为 200 mV、260 mV 和 340 mV 相应的 n 值为 2、2 和 l。 (3)个体吸收 Soret 和 Alpha 峰的最大值为 429 和 602 nm； 446 和 605 纳米； 分别为 448 和 607 nm。 (4) 细胞色素a-3是具有以下成分的成分： Soret 最大值为 429 nm，Aplpha 最大值为 602 nm。 (5) 氧化还原电位 血红素 a-3 受血红素 a 氧化还原状态的控制；是 200 毫伏 当血红素 a 被还原时，大于 420 mV 当血红素 a 被氧化时。 (6)血红素a-3的Em在一氧化碳气氛中不升高 这种行为表明质子对质子的束缚力较弱 还原配体酶比氧化形式。 我们对所有线粒体细胞色素的研究的总体结果 是电子传输链一次传递 2 个电子 比一。 这个结论与其他一些结论是一致的 观察。 我们分析了早期的数据采集方法 分析并发现它们不能溶解混合物 以及我们的方法揭示的细胞色素的特征。