Macfarlane N, Ainsworth S
Biochem J. 1974 Jun;139(3):499-508. doi: 10.1042/bj1390499.
The paper reports a study of the reaction between phosphoenolpyruvate, ADP and Mg(2+) catalysed by pig liver pyruvate kinase when activated by fructose diphosphate and K(+). The experimental results are consistent with two non-sequential mechanisms in which the substrates and products of the reaction are phosphoenolpyruvate, ADP, Mg(2+), pyruvate and MgATP. Pyruvate release occurs before ADP binding. Two Mg(2+) ions are involved, though the two Mg(2+)-binding sites cannot be occupied simultaneously. An isomerized enzyme complex forms before release of MgATP. Values were determined for the Michaelis constants of the reaction. Apparent MgATP inhibition constants are also given.
该论文报道了一项关于在果糖二磷酸和钾离子激活下，猪肝丙酮酸激酶催化磷酸烯醇丙酮酸、二磷酸腺苷（ADP）和镁离子（Mg²⁺）之间反应的研究。实验结果与两种非顺序机制一致，在这两种机制中，反应的底物和产物分别是磷酸烯醇丙酮酸、ADP、Mg²⁺、丙酮酸和镁三磷酸腺苷（MgATP）。丙酮酸在ADP结合之前释放。反应涉及两个镁离子，尽管两个镁离子结合位点不能同时被占据。在MgATP释放之前会形成一种异构化的酶复合物。测定了该反应的米氏常数，还给出了表观MgATP抑制常数。
