应用虚拟筛选方法寻找链阳霉素A乙酰转移酶抑制剂(英文)  

Identification of novel inhibitors of the streptogramin group A acetyltransferase via virtual screening

作　　者：王光凤[1] 黄牛 孟志宏[1] 刘全海[1] 

机构地区：[1]上海医药工业研究院,上海200437 [2]University of California at San Francisco

出　　处：《药学学报》2007年第1期47-53,共7页Acta Pharmaceutica Sinica

摘　　要：维吉尼亚霉素乙酰转移酶D(VatD)通过灭活链阳霉素A而在链阳霉素耐药性的产生中起重要作用。本研究采用虚拟筛选技术寻找VatD的抑制剂,此VatD抑制剂可以和链阳霉素联合使用,从而提供新的治疗耐药菌感染的方法。作者首次应用基于结构的虚拟筛选方法(分子对接)从含300000化合物的商业化数据库中筛选对抗VatD底物结合位点的化合物,从200个评分最高的化合物中选取26个测定对VatD酶活性的抑制作用。将构建的质粒pRSETB/vatD转染宿主细胞E.coli(TrxB)用于过表达,纯化的VatD对维吉尼亚霉素M1表现乙酰转移酶活性。26个化合物中有3个对VatD表现抑制作用,IC50分别为168.6,91.0和55.2μmol.L-1。其他化合物在反应体系中不溶解和/或对酶活性的抑制作用很小(IC50>200μmol.L-1)。本文首次设计VatD的小分子化合物抑制剂,发现了3个有活性的化合物,希望其可作为先导化合物进一步发展为新的对抗链阳霉素耐药性的药物。Virginiamycin acetyltransferase D （VatD） plays a vital rule in streptogramins resistance by chemically inactivating streptogramin A. Therefore, it is desirable to discover novel small molecular weight inhibitors of VatD via state-of-the-art virtual screening techniques. This ＂cocktail＂ strategy by combining VatD inhibitor with streptogramins may provide new therapeutic opportunity for resistant bacteria infections. Structure-based virtual screening method （molecular docking） was applied to rank and score a chemical database containing 300 000 commercially available compounds against the VatD substrate binding site. Twenty six out of the 200 top scored compounds from the docking calculation were selected and submitted to the VatD enzymatic inhibition assay. The plasmid pRSET B/vatD was constructed and transformed into E. coli （trxB） host cells for over-expression, and VatD enzyme was purified and validated by showing acetyltransferase activity to Virginiamycin M1. Three out of these 26 tested compounds showed enzymatic inhibition on VatD with IC50 168.6, 91.0 and 55.2μmol·L^-1, separately. Other compounds could not be dissolved in the system and/or had little effect on the enzyme （IC50 〉 200μmol·L^-1）. To our knowledge, it is first time that small molecular weight organic compounds were identified as VatD inhibitors. It is expected that the VatD inhibitors identified at present study could serve as lead compounds for the further development of the novel therapeutic agents to overcome streptogramins resistance.

关 键 词：链阳霉素A 维吉尼亚霉素乙酰转移酶D 虚拟筛选 抑制剂设计 

分 类 号：R916[医药卫生—药学]