De Clerck Y A, Yean T D, Ratzkin B J, Lu H S, Langley K E
Division of Hematology/Oncology, Childrens Hospital of Los Angeles, California.
J Biol Chem. 1989 Oct 15;264(29):17445-53.
Two metalloproteinase inhibitors were purified from serum-free medium conditioned by bovine aortic endothelial cells. One of these inhibitors, with a molecular weight of 30,000-34,000 (reduced) is identified as tissue inhibitor of metalloproteinases; the second inhibitor has a molecular weight of 27,500 (reduced) and 20,400 (unreduced), is not recognized by an antiserum against bovine tissue inhibitor of metalloproteinases, appears unglycosylated, and has 51% identity with tissue inhibitor of metalloproteinases by NH2-terminal amino acid sequence analysis. This inhibitor has antiproteinase activities similar to those of tissue inhibitor of metalloproteinases, with inhibition of classical collagenase, type IV collagenase, and gelatinases but not trypsin, plasmin, or bacterial collagenase. Other properties shared with tissue inhibitor of metalloproteinases include trypsin sensitivity, acid and heat resistance, and inactivation by reduction-alkylation. The presence of these inhibitors in endothelial cells suggests that they may play important roles in protecting the integrity of the vascular basement membrane.
从牛主动脉内皮细胞条件培养的无血清培养基中纯化出两种金属蛋白酶抑制剂。其中一种抑制剂，还原状态下分子量为30,000 - 34,000，被鉴定为金属蛋白酶组织抑制剂；第二种抑制剂还原状态下分子量为27,500，非还原状态下为20,400，不能被抗牛金属蛋白酶组织抑制剂的抗血清识别，似乎未糖基化，通过氨基末端氨基酸序列分析，与金属蛋白酶组织抑制剂有51%的同源性。这种抑制剂具有与金属蛋白酶组织抑制剂相似的抗蛋白酶活性，能抑制经典胶原酶、IV型胶原酶和明胶酶，但不抑制胰蛋白酶、纤溶酶或细菌胶原酶。与金属蛋白酶组织抑制剂共有的其他特性包括对胰蛋白酶敏感、耐酸耐热以及通过还原烷基化失活。这些抑制剂在内皮细胞中的存在表明它们可能在保护血管基底膜的完整性方面发挥重要作用。
