Khailova L S, Alexandrovitch O V, Severin S E
Biochem Int. 1985 Feb;10(2):291-300.
The properties of the pyruvate dehydrogenase component isolated from the pigeon breast muscle pyruvate dehydrogenase complex were studied upon inactivation of the enzyme in an incomplete reaction mixture: in the presence of cofactors and pyruvate, and in the absence of electron acceptors. The substrate-dependent inactivation was shown to result in the modification of two sulfhydryl groups per mole of the enzyme, in the appearance of a maximum at 235 nm in the protein absorption spectrum, and in the involvement of 1.5 moles of the [2-14C]-pyruvate fragment per mole of the pyruvate dehydrogenase. The fragment-protein bond is acid-stable, labile in alkali, and breaks up in the presence of performic acid, neutral hydroxylamine and dithiothreitol. An acetyl-substituted form of pyruvate dehydrogenase appearing with the participation of sulfhydryl enzyme groups is suggested.
在不完全反应混合物中使酶失活的情况下，研究了从鸽胸肌丙酮酸脱氢酶复合物中分离出的丙酮酸脱氢酶组分的性质：在存在辅因子和丙酮酸且不存在电子受体的情况下。结果表明，底物依赖性失活导致每摩尔酶有两个巯基被修饰，蛋白质吸收光谱在235nm处出现最大值，并且每摩尔丙酮酸脱氢酶有1.5摩尔的[2-14C] - 丙酮酸片段参与。片段与蛋白质的键对酸稳定，在碱中不稳定，在过甲酸、中性羟胺和二硫苏糖醇存在下会断裂。有人提出，巯基酶基团参与会出现乙酰取代形式的丙酮酸脱氢酶。
