STUDIES ON THE ELECTRON TRANSFER SYSTEM .4. THE ELECTRON TRANSFER PARTICLE
STUDIES ON THE ELECTRON TRANSFER SYSTEM .4. THE ELECTRON TRANSFER PARTICLE
复制标题
DOI：
10.1016/0006-3002(56)90058-0
复制
发表时间：
1956-01-01
期刊：
影响因子：
--
通讯作者：
GREEN, DE
中科院分区：
文献类型：
--
作者：
CRANE, FL;GLENN, JL;GREEN, DE
描述了从牛心线粒体获得的电子转移颗粒（ETP）的制备和性质。 ETP 在 38° 下每分钟每毫克催化 5.7 微摩尔 DPNH 和 2 微摩尔琥珀酸的氧化。该比活性比原始线粒体悬浮液大3-5倍。这 2 个氧化反应受到 (1) 磷酸盐浓度、(2) 金属络合剂的存在和 (3) 介质的离子强度的深刻影响。 ETP 制剂含有恒定比例的黄素、细胞色素 a、b 和 c1、非血红素铁和铜，以及根据分离条件不同数量的细胞色素 c。黄素和血红素均可被任一底物还原且还原程度相同。已除去大部分细胞色素 c 的 ETP 制剂显示，在分子 O2 氧化 DPNH 时不需要添加细胞色素 c，而在某些但不是所有条件下，在琥珀酸氧化中则部分需要细胞色素 c。 ETP 暴露于脱氧胆酸盐会产生一种可以轻松与外部细胞色素 c 相互作用的颗粒。还描述了诱导 ETP 片段化的程序。讨论了 ETP 恒定组成这一事实对于电子传输动力学的重要性。
The preparation and properties of an electron transfer particle (ETP) obtained from beef heart mitochondria are described. ETP catalyzes the oxidation of 5.7 [mu]moles DPNH and 2 [mu]moles succi-nate per minute per mg at 38[degree]. This specific activity is 3-5 times greater than that of the original mitochondrial suspension. These 2 oxidative reactions are profoundly influenced by (1) concentration of phosphate, (2) the presence of metal complexing agents, and (3) the ionic strength of the medium. Preparations of ETP contain flavin, cytochromes a, b and c1, non-heme iron and copper in constant proportions as well as cytochrome c in variable quantity depending upon the conditions of isolation. Both flavin and hemes are reducible by either substrate and to the same complete extent. Preparations of ETP from which the bulk of cytochrome c has been removed show no requirement for added cytochrome c in the oxidation of DPNH by molecular O2, whereas a partial requirement for cytochrome c in the oxidation of succinate is demonstrable under some but not all conditions. The exposure of ETP to deoxycholate leads to a particle which can interact readily with external cytochrome c. Procedures which induce fragmentation of ETP are also described. The significance of the fact of the constant composition of ETP for the dynamics of electron transport is discussed.