Metformin与AMPKγ亚基结合位点的探究  

Study on the binding sites of Metformin to AMPKγ subunit

作　　者：张雅雅[1] 许英艺[1] 陈玉强[1] 

机构地区：[1]中国人民解放军第一七四医院,福建厦门361001

出　　处：《现代肿瘤医学》2018年第7期1004-1008,共5页Journal of Modern Oncology

摘　　要：目的:基于前期Metformin与AMPKγ亚基结合的研究,进一步确认二者间的结合机制。方法:采用分子对接方法模拟Metformin与AMPKγ亚基潜在的结合位点,通过定点突变技术对AMPKγ亚基进行修饰,以荧光滴定法为检测方法,检测Metformin对突变前后的AMPKγ内源荧光猝灭的改变。结果:获得一系列AMPKγ亚基的突变体AMPKγM84A、T88A、D89A、R117A、K126A及I149A,比较发现Metformin与AMPKγ的解离常数KD值为(3.76±0.45)μmol/L,与突变体AMPKγT88A的KD值约为未突(36.15±6.91)μmol/L,约为变前的10倍,提示88位中的苏氨酸T可能是Metformin的结合位点之一。结论:该结果一方面阐明Metformin与AMPKγ的结合情况,另一方面也为以AMPKγ亚基为靶点的抗肿瘤药物设计提供理论指导。Objective：To explore the binding mechanism of the interaction between AMPKγ and Metformin,which we had discovered in previous study.Methods：In order to determine interactive binding sites,the potential amino acid residues based on the molecular docking results were first substituted to alanine （A） respectively by site-directed mutagenesis technology,then,the degree of binding disruption was detected by fluorescence titration method after mutation.Results：The degree of binding disruption was assessed by the dissociation constant KD between Metformin and its acceptors.For most of the mutants such as AMPKγ M84A,T88A,D89A,R117A,K126A and I149A,all the apparent binding affinity of them were shared a magnitude equal to the wild-type AMPKγ [（3.76±0.45） μmol/L],but for AMPKγ T88A,the value of KD was （36.15±6.91） μmol/L,which was approximately 10 times more than the wild-type.Conclusion：The results suggested that the threonine （T） which located in 88（start with N-terminal） site of AMPKγ is important for the interaction between Metformin and AMPKγ.Our results not only illustrate the binding mechanism of Metformin and AMPKγ,but also can provide theoretical guidance for the design of antitumor drugs which target AMPKγ.

关 键 词：分子对接 二甲双胍 由AMP激活的蛋白激酶 定点突变 荧光滴定 

分 类 号：R730.53[医药卫生—肿瘤]