Fligiel S E, Lee E C, McCoy J P, Johnson K J, Varani J
Am J Pathol. 1984 Jun;115(3):418-25.
Pretreatment of hemoglobin with 50-5000 nmol hydrogen peroxide (H2O2) increased its susceptibility to proteolysis by a number of purified enzymes, including trypsin, chymotrypsin, elastase, and plasmin, and by the neutral protease of rat peritoneal leukocytes. Pretreatment of the protein substrate with catalase-inactivated H2O2 had no effect. Separation of the proteolytic fragments by G-75 Sephadex gel filtration indicated no apparent differences in the size distribution of the fragments produced by treatment with the H2O2/proteolytic enzyme combination as compared with enzyme treatment alone. A partially purified preparation of rat glomerular basement membrane was also treated with proteolytic enzyme alone or in combination with H2O2. As with the hemoglobin, pretreatment of the glomerular basement membrane with H2O2 increased its susceptibility to subsequent proteolytic attack. In addition, treatment of a basement membrane glycoprotein, fibronectin, with H2O2 also increased its sensitivity to subsequent proteolysis. These results suggest that in addition to their other proinflammatory activities, oxygen-derived metabolites may contribute to tissue destruction by altering the susceptibility of proteins to hydrolytic enzymes.
用50 - 5000纳摩尔过氧化氢（H₂O₂）对血红蛋白进行预处理，会增加其对多种纯化酶（包括胰蛋白酶、糜蛋白酶、弹性蛋白酶和纤溶酶）以及大鼠腹膜白细胞中性蛋白酶的蛋白水解敏感性。用过氧化氢酶失活的H₂O₂对蛋白质底物进行预处理则没有效果。通过G - 75葡聚糖凝胶过滤分离蛋白水解片段表明，与单独用酶处理相比，用H₂O₂/蛋白水解酶组合处理产生的片段在大小分布上没有明显差异。大鼠肾小球基底膜的部分纯化制剂也单独用蛋白水解酶或与H₂O₂联合处理。与血红蛋白一样，用H₂O₂对肾小球基底膜进行预处理会增加其对随后蛋白水解攻击的敏感性。此外，用过氧化氢处理基底膜糖蛋白纤连蛋白也会增加其对随后蛋白水解的敏感性。这些结果表明，除了其他促炎活性外，氧衍生代谢产物可能通过改变蛋白质对水解酶的敏感性来促进组织破坏。
