超滤亲和结合液相色谱-质谱联用和分子对接技术筛选茶叶中α-葡萄糖苷酶抑制肽

Screening ofα-Glucosidase Inhibitory Peptides from Tea Leaves using Ultrafiltration Affinity Combined with Liquid Chromatography-Mass Spectrometry and Molecular Docking Technology

目的:筛选茶叶中具有抑制α-葡萄糖苷酶活性的肽段。方法:采用响应面法优化茶叶酶解产物制备工艺,超滤亲和法分离与α-葡萄糖苷酶结合的茶多肽,液相色谱-质谱联用对分离肽段进行序列测定,生物信息学方法进行虚拟筛选。结果:茶叶酶解产物最佳制备工艺为碱性蛋白酶酶解温度50℃,酶解时间3 h,液料比10:1(mL/g),对α-葡萄糖苷酶抑制率为57.29%,从中鉴定出624条肽段,筛选出一条四肽LIGF具有α-葡萄糖苷酶抑制活性,在5 mg/mL的浓度下对α-葡萄糖苷酶的最大抑制率为88.13%,IC_(50)值为1.22 mg/mL。分子对接显示,LIGF与α-葡萄糖苷酶能形成5个氢键,结合能为−3.51 kJ,具有高的亲和力、稳定性以及与α-葡萄糖苷酶结合的能力。结论:LIGF具有成为Ⅱ型糖尿病治疗药物的潜在价值。

Objective:To screen for tea peptides with inhibitory activity againstα-glucosidase.Methods:The response surface method was used to optimize the preparation process of tea peptides.Affinity ultrafiltration was used to isolate tea peptides that bind withα-glucosidase,and liquid chromatography-mass spectrometry was used to determine the sequence of the isolated peptides.Virtual screening was performed using bioinformatics methods.Results:The optimal preparation process of tea leaf enzymatic hydrolysis products was alkaline protease hydrolysis temperature of 50℃,enzymatic hydrolysis time of 3 h,and a liquid-to-solid ratio of 10:1(mL/g).Theα-glucosidase inhibitory rate was 57.29%.From this,624 peptide segments were identified,and LIGF was selected for itsα-glucosidase inhibitory activity.At a concentration of 5 mg/mL,LIGF exhibited a maximum inhibition rate of 88.13%againstα-glucosidase and an IC_(50) value of 1.22 mg/mL.Molecular docking showed that LIGF could form 5 hydrogen bonds withα-glucosidase,and the binding energy was-3.51 kJ,indicating a high affinity,stability and ability to bind toα-glucosidase.Conclusion:LIGF had potential value as a therapeutic drug for type II diabetes.