Tischler M E, Fagan J M, Allen D
Prog Clin Biol Res. 1985;180:363-72.
With increasing muscle size, incubated or fresh-frozen leg muscles showed a more reduced redox state and slower proteolysis. The ln of these data gave a linear correlation showing faster proteolysis under more oxidized conditions. In incubated diaphragms, the inhibitory effects of insulin and catecholamines on proteolysis were associated with a more reduced state. Fasting, trauma or cortisol treatment led to accelerated proteolysis and a more oxidized state. Long term fasting and refeeding supported this relationship, as did streptozotocin diabetes. Like the NAD+ and NADP+ redox couples, the glutathione couple seemed to fit this relationship. Use of proteinase inhibitors showed that the redox state probably mediated the effects of the various factors on proteolysis rather than vice versa. Muscle contains thioltransferase which catalyzes the formation of glutathione-protein mixed disulfides. We propose that increased formation of oxidized glutathione and its interaction with muscle proteins may act as a signal for the initiation of proteolysis.
随着肌肉体积的增加，孵育的或新鲜冷冻的腿部肌肉显示出氧化还原状态降低更多且蛋白水解更慢。这些数据的自然对数呈现线性相关，表明在氧化程度更高的条件下蛋白水解更快。在孵育的膈肌中，胰岛素和儿茶酚胺对蛋白水解的抑制作用与氧化还原状态降低更多有关。禁食、创伤或皮质醇治疗导致蛋白水解加速和氧化还原状态升高。长期禁食和再喂养支持了这种关系，链脲佐菌素诱导的糖尿病也是如此。与NAD⁺和NADP⁺氧化还原对一样，谷胱甘肽对似乎也符合这种关系。使用蛋白酶抑制剂表明，氧化还原状态可能介导了各种因素对蛋白水解的影响，而不是相反。肌肉中含有硫醇转移酶，它催化谷胱甘肽 - 蛋白质混合二硫键的形成。我们提出，氧化型谷胱甘肽形成增加及其与肌肉蛋白的相互作用可能作为蛋白水解起始的信号。
