Membrane type 1 matrix metalloproteinase digests interstitial collagens and other extracellular matrix macromolecules
Membrane type 1 matrix metalloproteinase digests interstitial collagens and other extracellular matrix macromolecules
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DOI：
10.1074/jbc.272.4.2446
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发表时间：
1997-01-24
影响因子：
4.8
通讯作者：
Okada, Y
中科院分区：
文献类型：
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作者：
Ohuchi, E;Imai, K;Okada, Y
膜型1基质金属蛋白酶（MT 1-MMP）在癌细胞膜上表达并激活MMP-2的酶原（明胶酶A）。我们最近已经分离了与金属蛋白酶组织抑制剂2（TIMP-2）复合的MT 1-MMP，并通过明胶酶谱法证明了MT 1-MMP表现出明胶分解活性（Imai，H.，Ohuchi，E.，Aoki，T.，野村，H.，Fujii，Y.，Sate，H.，Seiki，M.，和Okada，Y.（1996）Cancer Res.56，2707-2710）。在本研究中，我们进一步纯化了缺失跨膜结构域的MT 1-MMP突变体（Delta MT 1）和人乳腺癌细胞系（MDA-MB-231细胞）分泌的天然MT 1-MMP，并检测了它们的底物特异性。两种蛋白酶都有活性，无需任何活化处理，可将I型（豚鼠）、II型（牛）和III型（人）胶原蛋白消化成特征性的3/4和1/4片段。I型胶原蛋白的切割位点是α 1（I）链的Gly（775）/Ile（776）键和α 2（I）链的Gly（775）-Leu（776）和Gly（781）-Ile（782）键。Delta MT 1比II型或III型胶原更优先水解I型胶原6.5或4倍，而MMP-1（组织胶原酶）比其他两种胶原更有效地水解III型胶原。Delta MT 1和MMP-1活性的定量分析表明Delta MT 1切割I型胶原的效率低5-7.1倍。另一方面，Delta MT 1的明胶分解活性是MMP-1的8倍。Delta MT 1还能抑制软骨蛋白聚糖、纤连蛋白、玻连蛋白和层粘连蛋白-1以及α（1）-蛋白酶抑制剂和α（2）-巨球蛋白。Delta MT 1对I型胶原的活性随着与MMP-2的共孵育而协同增加。这些结果表明，MT 1-MMP是一种细胞外基质降解酶共享的底物特异性与间质胶原酶，并表明，MT 1-MMP发挥了双重作用，在病理生理消化细胞外基质通过直接切割的底物和激活proMMP-2。
Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed on cancer cell membranes and activates the zymogen of MMP-2 (gelatinase A). We have recently isolated MT1-MMP complexed with tissue inhibitor of metalloproteinases 2 (TIMP-2) and demonstrated that MT1-MMP exhibits gelatinolytic activity by gelatin zymography (Imai, H., Ohuchi, E., Aoki, T., Nomura, H., Fujii, Y., Sate, H., Seiki, M., and Okada, Y. (1996) Cancer Res. 56, 2707-2710). In the present study, we have further purified to homogeneity a deletion mutant of MT1-MMP lacking the transmembrane domain (Delta MT1) and native MT1-MMP secreted from a human breast carcinoma cell line (MDA-MB-231 cells) and examined their substrate specificities. Both proteinases are active, without any treatment for activation, and digest type I (guinea pig), II (bovine), and III (human) collagens into characteristic 3/4 and 1/4 fragments. The cleavage sites of type I collagen are the Gly(775)/Ile(776) bond for alpha 1(I) chains and the Gly(775)-Leu(776) and Gly(781)-Ile(782) bonds for alpha 2(I) chains. Delta MT1 hydrolyzes type I collagen 6.5- or 4-fold more preferentially than type II or III collagen, whereas MMP-1 (tissue collagenase) digests type III collagen more efficiently than the other two collagens. Quantitative analyses of the activity of Delta MT1 and MMP-1 indicate that Delta MT1 is 5-7.1-fold less efficient at cleaving type I collagen. On the other hand, gelatinolytic activity of Delta MT1 is 8-fold higher than that of MMP-1. Delta MT1 also digests cartilage proteoglycan, fibronectin, vitronectin and laminin-1 as well as alpha(1)-proteinase inhibitor and alpha(2)-macroglobulin. The activity of Delta MT1 on type I collagen is synergistically increased with co-incubation with MMP-2. These results indicate that MT1-MMP is an extracellular matrix-degrading enzyme sharing the substrate specificity with interstitial collagenases, and suggest that MT1-MMP plays a dual role in pathophysiological digestion of extracellular matrix through direct cleavage of the substrates and activation of proMMP-2.