摘要
目的研究黄柏碱对α-葡萄糖苷酶的体外抑制作用、作用类型和分子机制。方法建立α-葡萄糖苷酶抑制剂体外筛选模型,测定黄柏碱对α-葡萄糖苷酶的抑制率,并采用动力学方法研究黄柏碱的酶抑制作用类型。采用同源模建的方法构建酿酒酵母α-葡萄糖苷酶的三维结构,并运用分子对接技术分析黄柏碱抑制α-葡萄糖苷酶的分子作用机制。结果黄柏碱对α-葡萄糖苷酶的半数抑制浓度(IC50)为126.36 mg/L,且抑制率随浓度增加而增加。酶动力学结果显示,黄柏碱浓度增大,反应速率降低,Vmax、Km变小。分子对接结果显示,黄柏碱与α-葡萄糖苷酶位点5的结合能最低且其最好的对接构象结合能为-31.4 kJ/mol。黄柏碱与α-葡萄糖苷酶分子中的LYS15、SER295、HIS258等氨基酸残基形成氢键,与残基ALA289形成疏水相互作用以及与残基GLU10形成π-阴离子相互作用。结论黄柏碱是α-葡萄糖苷酶的可逆性反竞争性抑制剂,氢键、疏水作用和π-阴离子相互作用是黄柏碱与α-葡萄糖苷酶分子间的主要作用力。
OBJECTIVE To study the inhibitory effect and the inhibition type of phellodendrine onα-glucosidase in vitro and explore the molecular mechanism.METHODS An inhibitor screening model was established in vitro to examine the inhibitory rate of phellodendrine onα-glucosidase.The inhibition type was investigated by kinetic method.The three-dimensional structure ofα-glucosidase(Saccharomyces cerevisiae)was constructed by homology modeling method,and the inhibition molecular mechanism of phellodendrine onα-glucosidase was analyzed by molecular docking technology.RESULTS Phellodendrine displayed obvious inhibitory activity onα-glucosidase with an IC50 value of 126.36 mg/L,in a concentration-dependent manner.The results of enzyme kinetics indicated that the reaction rate was lowered and Vmax,Km were decreased with the concentration increasing of phellodendrine.The results of molecular docking showed that the binding energy of phellodendrine toα-glucosidase site 5 was the lowest,and its optimal docking conformation binding energy was-31.4 kJ/mol.Phellodendrine exerted its inhibitory activity by forming hydrogen bonds with amino acid residues such as LYS15,SER295,HIS258,hydrophobic interaction with ALA289 andπ-anion interaction with GLU10.CONCLUSION Phellodendrine is a reversible uncompetitive inhibitor ofα-glucosidase.The hydrogen bond,hydrophobic interaction andπ-anion interaction are main forces between phellodendrine andα-glucosidase.
作者
郑丽婷
周鸿
刘奕明
林爱华
ZHENG Li-ting;ZHOU Hong;LIU Yi-ming;LIN Ai-hua(The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510120, China;Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome, Guangzhou, 510120, China)
出处
《南京中医药大学学报》
CAS
CSCD
北大核心
2020年第6期853-858,共6页
Journal of Nanjing University of Traditional Chinese Medicine
基金
广东省科技计划项目(2017B030314166,2014A020221115)。
关键词
黄柏碱
Α-葡萄糖苷酶
反竞争性抑制
同源建模
分子对接
phellodendrine
α-glucosidase
uncompetitive inhibition
homology modeling
molecular docking
作者简介
第一作者:郑丽婷,女,硕士研究生,E-mail:1399079869@qq.com;通信作者:林爱华,男,研究员,主要从事药物新剂型及其生物有效性的研究,E-mail:linah76@163.com。
