5-二十一烷基间苯二酚抑制α-葡萄糖苷酶活性的分子机制  

Molecular Mechanisms for the Inhibition of 5-n-Heneicosylresorcinol on α-Glucosidase

作　　者：屠洁[1] 刘冠卉[1] 朱淑云[2] 曹喜涛[1] 李强[1] 季更生[1] TU Jie;LIU Guanhui;ZHU Shuyun;CAO Xitao;LI Qiang;JI Gengsheng(College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China;School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China)

机构地区：[1]江苏科技大学生物技术学院,江苏镇江212018 [2]江苏大学食品与生物工程学院,江苏镇江212013

出　　处：《食品科学》2017年第19期116-121,共6页Food Science

基　　金：江苏省镇江市重点研发计划--现代农业项目(NY2016020);江苏省高校自然科学研究面上项目(16KJB550001);江苏省博士后科研资助计划项目(1601058A)

摘　　要：小麦麸皮烷基间苯二酚可抑制α-葡萄糖苷酶活性,具有控制餐后高血糖的潜在作用,但是其作用分子机制尚未阐明。本实验采用荧光光谱、圆二色光谱以及分子对接技术研究小麦麸皮中含量最高的5-二十一烷基间苯二酚与α-葡萄糖苷酶的相互作用及抑制机制。结果显示,5-二十一烷基间苯二酚可使α-葡萄糖苷酶的内在荧光静态猝灭,不同温度(298、304、310 K)条件下结合常数K_A分别为149.8、46.2、20.3 L/mol;5-二十一烷基间苯二酚与酶分子结合降低酶分子结构中α-螺旋含量,增加β-折叠、β-转角以及无规卷曲含量;5-二十一烷基间苯二酚的苯环3—OH可与酶分子Tyr158的—COOH形成氢键,苯环5—OH的氢原子和氧原子分别与Lys156的—NH_2氢原子和Leu313的—COOH氧原子形成氢键,另外推测酶分子中Phe159、Pro312、Phe314、Asn415等氨基酸是与烷基间苯二酚形成疏水作用的重要位点。Alkylresorcinols from wheat bran have inhibitory activities onα-glucosidase,demonstrating the potential to control postprandial hyperglycemia.However,the molecular mechanisms have not been clarified yet.5-n-Heneicosylresorcinol is the most abundant alkylresorcinol homologue in wheat bran.In this context,fluorescence spectroscopy and circular dichroism(CD)spectroscopy along with molecular docking technique were used to study the molecular mechanisms for the inhibition of5-n-heneicosylresocinol onα-glucosidase.The results showed the intrinsic fluorescence ofα-glucosidase was quenched by5-n-heneicosylresocinol through a static quenching procedure.The binding constants at298,304and310K were149.8,46.2and20.3L/mol,respectively.The interaction between5-n-heneicosylresocinol andα-glucosidase changed the secondary structure ofα-glucosidase,as indicated by decreasedα-helix content and increased contents ofβ-sheet,β-turn and random coil.Hydrogen bonds were formed between the3-OH group on the benzene ring of5-n-heneicosylresocinol and the-COOH group on Tyr158inα-glucosidase,between the hydrogen atom of the5-OH group on the benzene ring and the hydrogen atom of the-NH2group on Lys156,and between the oxygen atom of the5-OH group on the benzene ring and the oxygen atom of the-COOH group on Leu313.Hydrophobic interaction between the alkyl chain of5-n-heneicosylresocinol and hydrophobic amino acid residues inα-glucosidase such as Phe159,Pro312,Phe314and Asn415was another important force to maintain the stability of the complex.

关 键 词：5-二十一烷基间苯二酚 Α-葡萄糖苷酶 抑制 分子机制 

分 类 号：TS201.2[轻工技术与工程—食品科学]