Van Der Plas L H, Jobse P A, Verleur J D
Biochim Biophys Acta. 1976 Apr 9;430(1):1-12. doi: 10.1016/0005-2728(76)90217-6.
Cytochrome c has two stimulatory effects on respiration of mitochondria especially those from wounded potato tuber. In the first place a stimulation of succinate- and NADH-consuming, antimycin-A-sensitive respiration, which reaches a maximal value at low cytochrome c concentrations, has been found. In the second place, at higher concentrations of cytochrome c a stimulation of NADH-consuming respiration occurs, which is antimycin-A-resistant, but KCN-sensitive. This antimycin-A-resistant, NADH-consuming respiration is absent, when no cytochrome c is added to the reaction medium. It is insensitive to metal chelators, to which the antimycin-A-and KCN-resistant plant mitochondrial alternative oxidase is sensitive. By measurements of NADH-cytochrome c reductase activities a corresponding antimycin-A-resistant NADH-cytochrome c reductase has been found, which is insensitive to osmotic shock treatment. A localization of this antimycin-A-resistant electron transport with NADH as the electron donor in the outer mitochondrial membrane is likely. In the mitochondrial preparations cytochrome c might stimulate by acting as an electron-carrier between the outer membrane reductase and the inner membrane cytochrome oxidase. A big increase of the outer membrane mediated electron transport in the mitochondria has been observed after wounding of potato tuber tissue. The ability of the tissue to produce this electron transport pathway after wounding disappeared after prolonged storage of the tubers. A possible function of this electron transport pathway in fatty acid desaturation during the wound-reaction is suggested.
细胞色素c对线粒体呼吸,尤其是受伤马铃薯块茎线粒体的呼吸有两种刺激作用。首先,已发现细胞色素c能刺激琥珀酸和NADH消耗型、抗霉素A敏感的呼吸作用,在低细胞色素c浓度时达到最大值。其次,在较高细胞色素c浓度下,会出现对NADH消耗型呼吸的刺激作用,这种呼吸作用对抗霉素A有抗性,但对氰化钾敏感。当不向反应介质中添加细胞色素c时,这种对抗霉素A有抗性的NADH消耗型呼吸作用不存在。它对金属螯合剂不敏感,而抗霉素A和氰化钾抗性的植物线粒体交替氧化酶对金属螯合剂敏感。通过测量NADH-细胞色素c还原酶活性,发现了一种相应的对抗霉素A有抗性的NADH-细胞色素c还原酶,它对渗透压休克处理不敏感。以NADH作为电子供体的这种对抗霉素A有抗性的电子传递可能定位于线粒体外膜。在制备的线粒体中,细胞色素c可能通过作为外膜还原酶和内膜细胞色素氧化酶之间的电子载体而起刺激作用。在马铃薯块茎组织受伤后,观察到线粒体中外膜介导的电子传递大幅增加。在块茎长期储存后,受伤组织产生这种电子传递途径的能力消失。有人提出这种电子传递途径在伤口反应过程中脂肪酸去饱和中的可能作用。