Müller M, Müller H, Holzer H
J Biol Chem. 1981 Jan 25;256(2):723-7.
Phosphoenolpyruvate carboxykinase (EC 4.1.1.49) from Saccharomyces cerevisiae was purified to homogeneity. The enzyme is composed of four subunits of Mr = 64,000. Specific antibodies against phosphoenolpyruvate carboxykinase were raised in rabbits and purified by affinity chromatography. Phosphoenolpyruvate carboxykinase is rapidly inactivated when glucose is added to cells starved for carbon (Haarasilta, S., and Oura, E. (1975) Eur. J. Biochem. 52, 1-7; Gancedo, C., and Schwerzmann, K. (1976)( ARch. Microbiol. 109, 221-225). In the present study this inactivation has been analyzed by immunochemical techniques. It was found that the loss of catalytic activity is paralleled by a decrease in cross-reacting material which suggests degradation of the enzyme. In the absence of glucose the enzyme is degraded very slowly, which indicates that glucose-induced inactivation cannot simply be due to repression of enzyme synthesis in the presence of a rapid rate of degradation. Experiments with a proteinase-deficient mutant showed that proteinase B, carboxypeptidase Y, and carboxypeptidase S are not involved in the inactivation system.
来自酿酒酵母的磷酸烯醇式丙酮酸羧激酶（EC 4.1.1.49）被纯化至同质。该酶由四个分子量为64,000的亚基组成。针对磷酸烯醇式丙酮酸羧激酶的特异性抗体在兔体内产生，并通过亲和层析进行纯化。当向缺乏碳源的饥饿细胞中添加葡萄糖时，磷酸烯醇式丙酮酸羧激酶会迅速失活（哈拉西塔，S.，和奥拉，E.（1975年）《欧洲生物化学杂志》52卷，第1 - 7页；甘塞多，C.，和施韦茨曼，K.（1976年）《微生物学档案》109卷，第221 - 225页）。在本研究中，这种失活已通过免疫化学技术进行分析。发现催化活性的丧失与交叉反应物质的减少平行，这表明酶发生了降解。在没有葡萄糖的情况下，酶降解非常缓慢，这表明葡萄糖诱导的失活不能简单地归因于在快速降解速率存在时酶合成的抑制。用蛋白酶缺陷型突变体进行的实验表明，蛋白酶B、羧肽酶Y和羧肽酶S不参与失活系统。
