Mort J S, Leduc M, Recklies A D
Biochim Biophys Acta. 1981 Dec 15;662(2):173-80. doi: 10.1016/0005-2744(81)90027-9.
Pepsin treatment of ascitic fluid from patients with neoplasia generated a cysteine (thiol) proteinase activity which resembles cathepsin B (EC 3.4.22.1) in its requirements for thiol activators, susceptibility to inhibitors and specificity for synthetic substrates. As judged by gel filtration, pepsin reduced the molecular size of the latent enzyme from an Mr of 41,000 to 33,000 after activation. Both forms are larger than human liver cathepsin B. In addition to its presence in ascitic fluid, the pepsin-activated species was found in the medium of ascites cells maintained in culture. The latent enzyme may be an enzyme-inhibitor complex or an inactive precursor of a cathepsin B-like proteinase.
用胃蛋白酶处理肿瘤患者的腹水可产生一种半胱氨酸（硫醇）蛋白酶活性，该活性在对硫醇激活剂的需求、对抑制剂的敏感性以及对合成底物的特异性方面类似于组织蛋白酶B（EC 3.4.22.1）。通过凝胶过滤判断，胃蛋白酶激活后可使潜在酶的分子大小从41,000 Mr降至33,000 Mr。这两种形式都比人肝脏组织蛋白酶B大。除了存在于腹水中，在培养的腹水细胞培养基中也发现了胃蛋白酶激活的物种。潜在酶可能是一种酶 - 抑制剂复合物或组织蛋白酶B样蛋白酶的无活性前体。
