Lopina O D, Boldyrev A A
Biokhimiia. 1977 Mar;42(3):436-42.
High concentration of ATP is found to activate Ca-dependent ATPase from sarcoplasmic reticulum both in membrane fraction and in purified enzyme preparation. The treatment of Ca-ATPase preparation with tripsin results in the elimination of the activating effect of ATP, which is accompanied by the disappearance of 100.000 molecular weight protein and by the appearance of fragments with molecular weight of 45.000 and 55.000. Repeated freezing of the enzyme preparation eliminates activating effect of ATP. ATP action is analysed from the viewpoint of allosteric kinetics, which postulates the existence of two Ca-ATPase conformers, their mutual conversion being induced by ATP binding at allosteric center. Kinetic parameters of the conformers studied are calculated.
已发现高浓度的ATP可在膜组分和纯化的酶制剂中激活肌浆网中的钙依赖性ATP酶。用胰蛋白酶处理钙ATP酶制剂会导致ATP激活作用的消除，同时伴有100,000分子量蛋白质的消失以及出现分子量为45,000和55,000的片段。酶制剂的反复冻融消除了ATP的激活作用。从别构动力学的角度分析了ATP的作用，该理论假定存在两种钙ATP酶构象体，它们之间的相互转化是由ATP在别构中心的结合诱导的。计算了所研究构象体的动力学参数。
