Hübner G, König S, Koch M H, Hengstenberg W
Institut für Biochemie, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany.
Biochemistry. 1995 Dec 5;34(48):15700-3. doi: 10.1021/bi00048a014.
Solution X-ray scattering patterns of enzyme I of the phosphotransferase system from Staphylococcus carnosus indicate an increase in radius of gyration and molecular mass in the presence of Mg2+ or both Mg2+ and phosphoenolpyruvate, indicating a partial dimerization of enzyme I. Mg2+ ions are essential for both the dimerization and the activation, whereas the substrate phosphoenolpyruvate shifts the monomer--dimer equilibrium to the enzymatically active dimer by decreasing the dissociation rate of the phosphorylated dimer.
来自肉葡萄球菌的磷酸转移酶系统中酶I的溶液X射线散射模式表明，在存在Mg2+或同时存在Mg2+和磷酸烯醇丙酮酸的情况下，回转半径和分子量增加，这表明酶I发生了部分二聚化。Mg2+离子对于二聚化和激活都是必不可少的，而底物磷酸烯醇丙酮酸通过降低磷酸化二聚体的解离速率将单体-二聚体平衡转移到具有酶活性的二聚体。
