Pontremoli S, Melloni E, Salamino F, Sparatore B, Michetti M, Horecker B L
Arch Biochem Biophys. 1984 Feb 1;228(2):460-4. doi: 10.1016/0003-9861(84)90011-0.
The stoichiometry of complex formation between two lysosomal proteinases from rabbit liver, cathepsin M and fructose 1,6-bisphosphatase converting enzyme (CE), and their respective endogenous inhibitors was studied by the equilibrium gel penetration method. In each case the molecular weight of the complex was found to be the sum of the molecular weights of the proteinase and its inhibitor, indicating the formation of 1:1 complexes. From the reappearance of proteinase activity on dilution, it is concluded that complex formation is reversible. Localization of the proteinase activities on the outer surface of the lysosomes was confirmed in these experiments by the inhibition of this proteinase activity on addition of inhibitors to intact lysosomes. The digestion by subtilisin of rabbit liver aldolase and rabbit liver fructose 1,6-bisphosphatase, the endogenous substrates for the lysosomal proteinases, was unaffected by the inhibitors.
采用平衡凝胶渗透法研究了兔肝脏中的两种溶酶体蛋白酶——组织蛋白酶M和果糖1,6 -二磷酸酶转化酶（CE）与它们各自内源性抑制剂之间形成复合物的化学计量关系。在每种情况下，发现复合物的分子量是蛋白酶及其抑制剂分子量之和，表明形成了1:1的复合物。从稀释后蛋白酶活性的重现可以得出结论，复合物的形成是可逆的。在这些实验中，通过向完整的溶酶体中添加抑制剂来抑制这种蛋白酶活性，证实了蛋白酶活性定位于溶酶体的外表面。溶酶体蛋白酶的内源性底物——兔肝脏醛缩酶和兔肝脏果糖1,6 -二磷酸酶被枯草杆菌蛋白酶的消化不受抑制剂的影响。
