Morihara K, Tsuzuki H, Oda K
Infect Immun. 1979 Apr;24(1):188-93. doi: 10.1128/iai.24.1.188-193.1979.
The present study indicates that crystalline elastase of Pseudomonas aeruginosa is a very potent inactivator of human plasma alpha 1-proteinase inhibitor, the enzyme (E) inactivated the inhibitor (I) almost completely within 1 h at 25 degrees C at a molar ratio of E/I = 1:100. The crystalline P. aeruginosa protease also inactivated the inhibitor, but 100-fold less. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the alpha 1-proteinase inhibitor inactivated by the elastase and protease showed decreases in molecular weight of approximately 5,000 and 10,000, respectively. Regeneration of trypsin was negligible even when bovine trypsin-alpha 1-proteinase inhibitor complex (E/I = 1.0) was treated with the elastase. The affinity of alpha 1-proteinase inhibitor to trypsin was much higher than that to elastase. It was suggested that, assuming the pseudomonal proteases are produced and can inactivate alpha 1-proteinase inhibitor in vivo during pseudomonal diseases, the loss of alpha 1-proteinase inhibitor activity may permit the endogenous serine proteases to cause tissue destruction.
本研究表明，铜绿假单胞菌的结晶弹性蛋白酶是人类血浆α1-蛋白酶抑制剂的一种非常有效的失活剂，在25℃下，当酶（E）与抑制剂（I）的摩尔比为1:100时，该酶在1小时内几乎完全使抑制剂失活。铜绿假单胞菌的结晶蛋白酶也能使抑制剂失活，但活性仅为前者的1/100。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳表明，被弹性蛋白酶和蛋白酶失活的α1-蛋白酶抑制剂的分子量分别降低了约5000和10000。即使将牛胰蛋白酶-α1-蛋白酶抑制剂复合物（E/I = 1.0）用弹性蛋白酶处理，胰蛋白酶的再生也可忽略不计。α1-蛋白酶抑制剂对胰蛋白酶的亲和力远高于对弹性蛋白酶的亲和力。有人提出，假设在铜绿假单胞菌疾病期间，铜绿假单胞菌产生的蛋白酶能够在体内使α1-蛋白酶抑制剂失活，那么α1-蛋白酶抑制剂活性的丧失可能会使内源性丝氨酸蛋白酶导致组织破坏。
