Bodmer J L, Schnebli H P
Schweiz Med Wochenschr. 1984 Oct 6;114(40):1359-63.
Plasma proteinase inhibitors account for about 10% of the total protein in plasma. They provide one mechanism for the control of proteinase activity, thus regulating many important biological reactions such as blood coagulation. Most plasma inhibitors are specific for one or a few related proteinases and control a particular biological event or pathway. Two other inhibitors, the alpha 2-macroglobulin (alpha 2M) and the alpha 1-proteinase (alpha 1PI = alpha 1-antitrypsin) have a broader specificity. The role of alpha 1PI, although theoretically able to inhibit a large number of enzymes, is the inhibition of leukocytic elastase. This function is particularly important in the lung where elastase may be released from neutrophils particularly in smokers. alpha 2-Macroglobulin reacts with a large number of very different proteinases by a mechanism quite different from those of the other inhibitors. The physiological role of this inhibitor is not clearly understood although it may act as a "back-up" inhibitor when levels of other inhibitors are low or if no specific inhibitor is available.
血浆蛋白酶抑制剂约占血浆总蛋白的10%。它们为控制蛋白酶活性提供了一种机制，从而调节许多重要的生物反应，如血液凝固。大多数血浆抑制剂对一种或几种相关蛋白酶具有特异性，并控制特定的生物事件或途径。另外两种抑制剂，α2-巨球蛋白（α2M）和α1-蛋白酶（α1PI = α1-抗胰蛋白酶）具有更广泛的特异性。α1PI的作用虽然理论上能够抑制大量酶，但主要是抑制白细胞弹性蛋白酶。这种功能在肺部尤为重要，因为弹性蛋白酶可能特别是在吸烟者的中性粒细胞中释放。α2-巨球蛋白通过一种与其他抑制剂截然不同的机制与大量非常不同的蛋白酶发生反应。尽管当其他抑制剂水平较低或没有特异性抑制剂时，它可能作为“备用”抑制剂起作用，但其生理作用尚不清楚。
