Matrix metalloproteinase triple-helical peptidase activities are differentially regulated by substrate stability
Matrix metalloproteinase triple-helical peptidase activities are differentially regulated by substrate stability
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DOI：
10.1021/bi048938i
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发表时间：
2004-09-14
期刊：
影响因子：
2.9
通讯作者：
Fields, GB
中科院分区：
文献类型：
--
作者：
Minond, D;Lauer-Fields, JL;Fields, GB
Matrix metalloproteinases (MMPs) are involved in physiological remodeling as well as pathological destruction of tissues. The turnover of the collagen triple-helical structure has been ascribed to several members of the MMP family, but the determinants for collagenolytic specificity have not been identified. The present study has compared the triple-helical peptidase activities of MMP-1 and MMP-14 (membrane-type 1 MMP; MT1-MMP). The ability of each enzyme to efficiently hydrolyze the triple helix was quantified using chemically synthesized fluorogenic triple-helical substrates that, via addition of N-terminal alkyl chains, differ in their thermal stabilities. One series of substrates was modeled after a collagenolytic MMP consensus cleavage site from types I-III collagen, while the other series had a single substitution in the P-1' subsite of the consensus sequence. The substitution of Cys(4-methoxybenzyl) for Leu in the P-1' subsite was greatly favored by MMP-14 but disfavored by MMP-1. An increase in substrate triple-helical thermal stability led to the decreased ability of the enzyme to cleave such substrates, but with a much more pronounced effect for MMP-1. Increased thermal stability was detrimental to enzyme turnover of substrate (k(cat)), but not binding (K-M). Activation energies were considerably lower for MMP-14 hydrolysis of triple-helical substrates compared with MMP-1. Overall, MMP-1 was found to be less efficient at processing triple-helical structures than MMP-14. These results demonstrate that collagenolytic MMPs have subtle differences in their abilities to hydrolyze triple helices and may explain the relative collagen specificity of MMP-1.
