Ramakrishna S, Benjamin W B
Biochem Biophys Res Commun. 1983 Dec 16;117(2):435-43. doi: 10.1016/0006-291x(83)91219-6.
Native acetyl CoA carboxylase was phosphorylated by catalytic subunit of cyclic AMP-dependent protein kinase and ATP-citrate lyase kinase to 1 and 0.5 mol/subunit respectively. Both protein kinases added together increased acetyl CoA carboxylase phosphorylation additively. Partial proteolysis of 32P-acetyl CoA carboxylase followed by electrophoretic analysis showed that the 32P-phosphopeptides generated from acetyl CoA carboxylase phosphorylated with lyase kinase were different from the peptides obtained from the enzyme phosphorylated by cyclic AMP-dependent protein kinase. Mapping of tryptic 32P-phosphopeptides by high performance liquid chromatography showed that the major phosphopeptides phosphorylated by ATP-citrate lyase kinase were different from the major phosphopeptides phosphorylated by cyclic AMP-dependent protein kinase. The results suggest that at least one different site on acetyl CoA carboxylase is preferentially phosphorylated by each protein kinase.
天然乙酰辅酶A羧化酶被环磷酸腺苷依赖性蛋白激酶的催化亚基和ATP-柠檬酸裂解酶激酶分别磷酸化为1摩尔/亚基和0.5摩尔/亚基。两种蛋白激酶共同作用时，乙酰辅酶A羧化酶的磷酸化呈加和性增加。对32P-乙酰辅酶A羧化酶进行部分蛋白酶解，然后进行电泳分析，结果表明，由裂解酶激酶磷酸化的乙酰辅酶A羧化酶产生的32P-磷酸肽与由环磷酸腺苷依赖性蛋白激酶磷酸化的该酶所获得的肽不同。通过高效液相色谱法对胰蛋白酶32P-磷酸肽进行图谱分析表明，由ATP-柠檬酸裂解酶激酶磷酸化的主要磷酸肽与由环磷酸腺苷依赖性蛋白激酶磷酸化的主要磷酸肽不同。结果表明，每种蛋白激酶至少优先磷酸化乙酰辅酶A羧化酶上的一个不同位点。
