ACTIVATION OF THE 92-KDA GELATINASE BY STROMELYSIN AND 4-AMINOPHENYLMERCURIC ACETATE - DIFFERENTIAL PROCESSING AND STABILIZATION OF THE CARBOXYL-TERMINAL DOMAIN BY TISSUE INHIBITOR OF METALLOPROTEINASES (TIMP)
ACTIVATION OF THE 92-KDA GELATINASE BY STROMELYSIN AND 4-AMINOPHENYLMERCURIC ACETATE - DIFFERENTIAL PROCESSING AND STABILIZATION OF THE CARBOXYL-TERMINAL DOMAIN BY TISSUE INHIBITOR OF METALLOPROTEINASES (TIMP)
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DOI：
10.1074/jbc.270.11.6351
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发表时间：
1995-03-17
影响因子：
4.8
通讯作者：
WELGUS, HG
中科院分区：
文献类型：
--
作者：
SHAPIRO, SD;FLISZAR, CJ;WELGUS, HG
基质金属蛋白酶92-kDa明胶酶是炎症细胞的主要产物。巨噬细胞合成并分泌这种蛋白酶作为与金属蛋白酶组织抑制剂（TIMP）相关的酶原（92（TIMP）），而中性粒细胞将其作为无TIMP的酶原从次级颗粒中储存和释放（92（无TIMP））。金属蛋白酶酶原可以在体外被多种试剂激活，包括有机汞和蛋白酶，导致8-10-kDa NH 2-末端结构域的丢失，这破坏了保守的半胱氨酸残基与催化锌分子的相互作用。我们报告说，92-kDa明胶酶的激活和加工不同，这取决于它与TIMP的关联和激活剂的性质。我们观察到，92（TIMP）经历经典的活化至82 kDa的基质分解素，而暴露于4-氨基苯汞乙酸（APMA）的结果在83 kDa的最终产品，仍然含有''前结构域''半胱氨酸。与TIMP的关联似乎稳定了COOH末端结构域，而92（无TIMP）被APMA转化为缺乏COOH末端部分的67 kDa的最终产物。在维持半胱氨酸-锌破坏的APMA的持续存在下，67-kDa物质至少与经典的82 kDa一样活跃。相比之下，基质溶解素对92（无TIMP）的活化最初产生82-kDa形式，随后最终转化为缺乏亲本分子的催化结构域的50-kDa种类。因此，尽管92（不含TIMP）的基质溶解素活化最初是有效的，但活性82-kDa形式是短暂的，并且被无活性的50-kDa产物取代。92-kDa明胶酶的这种复杂活化模式可用于限制其暴露于基质溶解素后的蛋白水解能力，并且可用于调节体内蛋白酶活性。
The matrix metalloproteinase 92-kDa gelatinase is a major product of inflammatory cells. Macrophages synthesize and secrete this proteinase as a proenzyme in association with tissue inhibitor of metalloproteinases (TWIP) (92(TIMP)), whereas neutrophils store and release it from secondary granules as a TIMP-free proenzyme (92(TIMP-free)). Metalloproteinase proenzymes can be activated in vitro by a variety of agents, including organomercurials and proteinases, resulting in loss of an 8-10-kDa NH2-terminal domain which disrupts the interaction of a conserved cysteine residue with the catalytic zinc molecule. We report that the activation and processing of 92-kDa gelatinase differs depending on its association with TIMP and the nature of the activating agent. We observed that 92(TIMP) undergoes classic activation to 82 kDa by stromelysin, whereas exposure to 4-aminophenylmercuric acetate (APMA) results in a final product of 83 kDa that still contains the ''prodomain'' cysteine. Association with TIMP appears to stabilize the COOH-terminal domain, whereas 92(TIMP-free) is converted by APMA to a final product of 67 kDa lacking the COOH-terminal portion. In the continued presence of APMA, which maintains cysteine-zinc disruption, the 67-kDa species is at least as active as the classic 82 kDa. In contrast, activation of 92(TIMP-free) by stromelysin initially generates the 82-kDa form which is followed by final conversion to a 50-kDa species that lacks the cata lytic domain of the parent molecule. Therefore, although stromelysin activation of 92(TIMP-free) is initially efficient, the active 82-kDa form is short-lived and is replaced by an inactive 50-kDa product, This complex pattern of activation of the 92-kDa gelatinase may serve to restrict its proteolytic capacity following exposure to stromelysin and may serve to regulate proteinase activity in vivo.