Nakai N, Fujii Y, Kobashi K, Hase J
Biochem Biophys Res Commun. 1983 Jan 27;110(2):682-7. doi: 10.1016/0006-291x(83)91203-2.
Treatment of rat liver-type pyruvate kinase with rabbit liver cathepsin B at pH 7.0 caused loss of activity in the standard assay with 0.6 mM of phosphoenolpyruvate. The modified enzyme exhibited about 10% of the original activity when assayed with 2.0 mM of the substrate. No detectable change in the subunit molecular weight of the enzyme occurred during inactivation. On addition of 4 microM fructose 1,6-bisphosphate the activity of the treated enzyme was restored to that of the original enzyme. Limited proteolysis of the enzyme by cathepsin B appears to enhance the requirement for the positive effector, fructose 1,6-bisphosphate.
在pH 7.0条件下，用兔肝组织蛋白酶B处理大鼠肝型丙酮酸激酶，在以0.6 mM磷酸烯醇丙酮酸进行的标准测定中导致酶活性丧失。当用2.0 mM底物进行测定时，修饰后的酶表现出约为原始活性10%的活性。在失活过程中，酶的亚基分子量未发生可检测到的变化。添加4 microM果糖1,6-二磷酸后，处理后酶的活性恢复至原始酶的活性。组织蛋白酶B对该酶的有限蛋白水解似乎增强了对正向效应物果糖1,6-二磷酸的需求。
