Constraining specificity in the N-domain of tissue inhibitor of metalloproteinases-1; gelatinase-selective inhibitors
Constraining specificity in the N-domain of tissue inhibitor of metalloproteinases-1; gelatinase-selective inhibitors
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DOI：
10.1110/ps.072978507
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发表时间：
2007-09-01
期刊：
影响因子：
8
通讯作者：
Brew, Keith
中科院分区：
文献类型：
--
作者：
Hamze, Asmaa B.;Wei, Shuo;Brew, Keith
金属蛋白酶组织抑制剂（tissue inhibitors of metalloproteinases，TIMPs）是基质金属蛋白酶（matrix metalloproteinases，MMPs）的内源性抑制剂。由于不受调节的MMP活性与关节炎、癌症和动脉粥样硬化有关，因此作为疾病相关MMP的选择性抑制剂的TIMP变体具有潜在的治疗价值。TIMP/MMP复合物的结构表明，大多数与MMP的相互作用涉及TIMP的N端五肽和占据活性位点的引发和未引发区域的C-D β链连接体。β链A和B之间的环形成了一些MMP的次级相互作用位点，范围从TIMP-2/膜1型（MT 1）-MMP复合物中的多个接触到TIMP-1/MMP-1复合物中的无接触。TIMP-1及其抑制结构域N-TIMP-1是MT 1-MMP的弱抑制剂;将TIMP-2的较长AB环移植到N-TIMP-1中不会改善抑制作用，但这种变化会损害与MMP-3和MMP-7的结合。用N-TIMP-1进行的突变研究表明，与其他N-TIMP相比，其对MT 1-MMP的弱抑制是由相互作用位点中的多个（> 3个）序列差异引起的。N-TIMP-1的Thr 2的取代强烈影响MMP的选择性;通常降低MMP亲和力的Arg和Gly对与MMP-9结合的影响较小。当Arg突变加入到N-TIMP-1（AB 2）突变体中时，它产生明胶酶特异性抑制剂，MMP-2和-9的Ki值分别为2.8和0.4 nM。有趣的是，Gly突变体对MMP-9的Ki为2.1 nM，对MMP-2的Ki> 40 μ M，表明工程化的TIMP可以区分相同亚家族中的MMP。
The tissue inhibitors of metalloproteinases ( TIMPs) are endogenous inhibitors of the matrix metalloproteinases ( MMPs). Since unregulated MMP activities are linked to arthritis, cancer, and atherosclerosis, TIMP variants that are selective inhibitors of disease-related MMPs have potential therapeutic value. The structures of TIMP/MMP complexes reveal that most interactions with the MMP involve the N-terminal pentapeptide of TIMP and the C-D beta-strand connector which occupy the primed and unprimed regions of the active site. The loop between beta-strands A and B forms a secondary interaction site for some MMPs, ranging from multiple contacts in the TIMP-2/membrane type-1 (MT1)-MMP complex to none in the TIMP-1/MMP-1 complex. TIMP-1 and its inhibitory domain, N-TIMP-1, are weak inhibitors of MT1-MMP; inhibition is not improved by grafting the longer AB loop from TIMP-2 into N-TIMP-1, but this change impairs binding to MMP-3 and MMP-7. Mutational studies with N-TIMP-1 suggest that its weak inhibition of MT1-MMP, as compared to other N-TIMPs, arises from multiple (> 3) sequence differences in the interaction site. Substitutions for Thr2 of N-TIMP-1 strongly influence MMP selectivity; Arg and Gly, that generally reduce MMP affinity, have less effect on binding to MMP-9. When the Arg mutation is added to the N-TIMP-1( AB2) mutant, it produces a gelatinase-specific inhibitor with Ki values of 2.8 and 0.4 nM for MMP-2 and -9, respectively. Interestingly, the Gly mutant has a Ki of 2.1 nM for MMP-9 and > 40 mu M for MMP-2, indicating that engineered TIMPs can discriminate between MMPs in the same subfamily.