从进化角度分析皮肤脱屑相关Kallikrein7蛋白家族潜在抑制剂结合点

Analysis of Inhibitor Binding Sites of Kallikrein7 Related with Skin Desquamation from an Evolutionary Perspective

KLK7是丝氨酸蛋白酶家族的一员,能够水解桥粒蛋白从而引起角质层细胞间粘合力下降,是治疗皮肤脱屑的靶标。为了研究KLK7潜在特异性抑制点,本研究利用NCBI的blastp寻找人KLK蛋白同源序列,然后对获得的同源序列在Smart中验证是否有丝氨酸胰蛋白酶保守功能域。并基于获得的59个人KLK7蛋白同源序列进行进化踪迹分析,对于获得的65个KLK7蛋白全家族保守残基进一步用序列对比和结构对比进化分析进行验证。然后用Metapocket预测人KLK7蛋白质潜在配基结合点,结合之前获得的61个KLK7蛋白全家族保守残基进行潜在的抑制剂结合点分析,Asp104和Arg123是潜在的特异抑制剂结合点。其中Asp204和Ile30之间的盐桥对蛋白质结构起到稳定作用,Arg123是KLK7的外结合点,为寻找KLK7特异性抑制剂奠定了理论基础。

Human kallikrein7（h K7） is a member of serine protease family that can contribute to desquamation by hydrolyzing extracellular proteins causing the decrease of adhesion between stratum corneum cells. It is a targets for the treatment of skin desquamation. In order to the discover specific inhibitors for KLK7, we searched homologous sequence of KLK7 with blastp in NCBI. A validation with Smart was carried out to find whether there was a conservative domain of trypsin serine protease. The 59 KLK7 protein homologous sequences that we got before were further analyzed by evolutionary trace and we obtained 65 highly conservative residues. We further confirmed the 65 highly conservative residues with multiple sequence alignment and structure comparison. And then we use Metapocket to predict the potential pocket and ligand binging sites. Based on the highly conservative residues and the potential binding sites of ligand, detailed analysis on the inhibitor binding site of KLK7 inhibitor was performed. The results indicated that Asp204 and Arg123 might be the binding site of KLK7 inhibitor. A salt bridge built between Asp204 and Ile30 stabilized the structure of KLK7. Arg123 was the exosite of KLK7 which might lay a theoretical foundation for the study of KLK7 specific inhibitors.