Virca G D, Travis J
J Biol Chem. 1984 Jul 25;259(14):8870-4.
Association rates have been determined for the interaction of human alpha 2-macroglobulin with human neutrophil elastase, cathepsin G, and human plasma kallikrein. Both of the neutrophil enzymes are rapidly inactivated by this inhibitor; however, the inactivation of plasma kallikrein is much slower. Comparison of the rates of inactivation with those already established for other inhibitors clearly indicate that alpha 1-proteinase inhibitor is the controlling inhibitor for neutrophil elastase and alpha 1-antichymotrypsin for cathepsin G, alpha 2-macroglobulin acting only as a secondary inhibitor. The control of plasma kallikrein would appear to be rather poor since neither alpha 2-macroglobulin nor C1-inhibitor appears to react very rapidly with this proteinase. Thus, a primary role for alpha 2-macroglobulin in directly inactivating proteinases in blood, under normal physiological conditions, remains to be established.
已测定人α2-巨球蛋白与人中性粒细胞弹性蛋白酶、组织蛋白酶G和人血浆激肽释放酶相互作用的结合速率。两种中性粒细胞酶都能被这种抑制剂迅速灭活；然而，血浆激肽释放酶的失活要慢得多。将失活速率与其他已确定的抑制剂的失活速率进行比较，清楚地表明α1-蛋白酶抑制剂是中性粒细胞弹性蛋白酶的主要控制抑制剂，α1-抗糜蛋白酶是组织蛋白酶G的主要控制抑制剂，α2-巨球蛋白仅作为次要抑制剂起作用。血浆激肽释放酶的控制似乎相当差，因为α2-巨球蛋白和C1-抑制剂似乎都不能与这种蛋白酶快速反应。因此，在正常生理条件下，α2-巨球蛋白在直接灭活血液中蛋白酶方面的主要作用仍有待确定。
