茶黄素抑制B类β-内酰胺酶的靶点确证及构效关系研究

耐甲氧西林金葡菌（MRSA）是常见的多药耐药病原菌。B类β-内酰胺酶(MBLs)在MRSA多重耐药性中发挥重要作用，可水解几乎所有β-内酰胺类抗生素。目前常用β-内酰胺酶抑制剂如舒巴坦钠，阿维巴坦等对MBLs均无明显抑制效果。近几年针对MBLs抑制剂的文献报道较多，但至今尚未有药物进入临床评价及应用。本课题组前期建立了MBLs抑制剂筛选平台，筛选到了多种对MBLs有抑制作用的天然化合物，其中茶黄素抑制MBLs效果最佳，进一步借助计算生物学方法初步确定了MBLs稳定三维结构及其与茶黄素结合区域。本项目拟在前期研究基础上，应用分子模拟、核磁共振及表面等离子体共振等方法进一步确证茶黄素与MBLs结合靶点，阐明其共性分子作用机制并进行定量构效关系分析，体内外试验验证茶黄素对MRSA耐药性的抑制作用以及协同美罗培南对细菌感染小鼠的治疗作用，以期为新型耐药抑制剂研发提供新的策略和先导化合物。

Methicillin-resistant Staphylococcus aureus (MRSA) is a common multidrug resistance pathogenic bacteria. Class B of β-lactamases (MBLs) play an critical role in the multiple drug resistance of MRSA, and almost all β-lactam antibiotics can be hydrolyzed by MBLs. MBLs cannot be effective suppressed by the commonβ-lactamases inhibitors, such as sulbactam, avibactam. In recent years, there are a lot of reports about MBLs inhibitors. However, up to now, there is no clinical evaluation and application of drugs. In preliminary studies, we found that several natural compounds could inhibit hydrolytic activity of MBLs, and Theaflavin has the best inhibition effect. With the computational biology methods, the stable 3D structures of MBLs and the binding regions of Theaflavin with MBLs were confirmed. On the basis of these results, the project is intended to further investigate the binding sites of Theaflavin with MBLs, clarify the common inhibition mechanism and analyse the quantitative structure-activity relationship via molecular modeling, NMR, and SPR. The inhibitory effect of Theaflavin against MRSA resistance and the therapeutic effect of Theaflavin with meropenem in vitro and in vivo would be determined via mouse model of MRSA infection. Together, this study will lay the new strategies and lead compounds for the development of anti- resistance inhibitors.