食品科学 ›› 2017, Vol. 38 ›› Issue (19): 116-121.doi: 10.7506/spkx1002-6630-201719019

• 基础研究 • 上一篇    下一篇

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

屠 洁1,刘冠卉1,*,朱淑云2,曹喜涛1,李 强1,季更生1   

  1. 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
  • 出版日期:2017-10-15 发布日期:2017-09-29
  • 基金资助:
    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)

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

TU Jie1, LIU Guanhui1,*, ZHU Shuyun2, CAO Xitao1, LI Qiang1, JI Gengsheng1   

  1. 1. College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China; 2. School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
  • Online:2017-10-15 Published:2017-09-29

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KA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—NH2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。

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

Abstract: Alkylresorcinols from wheat bran have inhibitory activities on α-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 of 5-n-heneicosylresocinol on α-glucosidase. The results showed the intrinsic fluorescence of α-glucosidase was quenched by 5-n-heneicosylresocinol through a static quenching procedure. The binding constants at 298, 304 and 310 K were 149.8, 46.2 and 20.3 L/mol, respectively. The interaction between 5-n-heneicosylresocinol and α-glucosidase changed the secondary structure of α-glucosidase, as indicated by decreased α-helix content and increased contents of β-sheet, β-turn and random coil. Hydrogen bonds were formed between the 3–OH group on the benzene ring of 5-n-heneicosylresocinol and the –COOH group on Tyr158 in α-glucosidase, between the hydrogen atom of the 5–OH group on the benzene ring and the hydrogen atom of the –NH2 group on Lys156, and between the oxygen atom of the 5–OH group on the benzene ring and the oxygen atom of the –COOH group on Leu313. Hydrophobic interaction between the alkyl chain of 5-n-heneicosylresocinol and hydrophobic amino acid residues in α-glucosidase such as Phe159, Pro312, Phe314 and Asn415 was another important force to maintain the stability of the complex.

Key words: 5-n-heneicosylresocinol, α-glucosidase, inhibition, molecular mechanisms

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