【摘要】 获得具有催化活性的人巨噬细胞弹性蛋白酶的催化区(hMECD),并建立有效的高通量筛选方法筛选其仰制剂.方法:在大肠杆菌中表达hMECD,并根据酶活性以比色法建立高通量筛选模型.对一批共8560个纯化合物和混合物进行了高通量筛选.结果:构建了有效的大肠杆菌表达系统.存在于包涵体中的表达蛋白在体外重折叠复性,经阴离子交 换柱层析的方法纯化,1L大肠杆菌培养物可得到23mg纯化的活性蛋白.该蛋白的重折叠复性和酶活性需要钙锌离子,但高浓度的锌离子则抑制其重折叠复性和活性.hMECD剪切合成底物包括一个硫酯和几个荧光发生的肽类底物,并在pH8.0显示最强的活性.对8560个化合物和混合物的高通量筛选发现了27个纯化合物和14个天然产物在20mg/L的浓度下具有大于80％的抑制活性.结论:建立了有效的人巨噬细胞弹性蛋白酶的催化区表达和纯化的方法.该重组蛋白抑制剂的高通量筛选模型具有有效、可信和快速的特点.更多还原

【Abstract】 To obtain a catalytically active human macrophage elastase catalytic domain (hMECD) and to establish an efficient high-throughput method for screening macrophage elastase inhibitors. METHODS: Catalytic domain of human macrophage elastase was expressed in E coli and characterized to establish a high-throughput screening assay using a colorimetric method. A set of 8560 pure compounds and mixtures were screened. RESULTS: We have constructed an efficient E coli system for this human protein expression, and the recombinant hMECD protein was purified to homogeneity using anion-exchange chromatography after in vitro refolding from inclusion bodies. The yield of active hMECD protein was 23 mg from one liter of E coli culture after purification. Calcium and zinc ions were required both in refolding and enzymatic activity, but high concentration of zinc inhibited the refolding and activity. The hMECD cleaved several synthetic substrates including a chromogenic thiopeptolide and fluorogenic peptides with optimal activity around pH 8.0. Screening of 8560 compounds and mixtures led to identify 27 pure compounds and 14 natural products with inhibitory activity higher than 80 % at 20 mg/L. CONCLUSION: An efficient expression and purification method for hMECD protein has been established, and the assay is effective, reliable, and fast in identifying the recombinant protein inhibitors.更多还原