摘要
通过抑制二肽基肽酶IV(Dipeptidyl-peptidase IV, DPP-IV)的活性,从而减少GLP-1的降解,提高血液中胰岛素的水平,是控制血糖水平的一种重要手段。本文以海参(Holothariatubulosa)为原料,通过探究蛋白酶种类、加酶量和酶解时间对酶解产物DPP-IV抑制活性、蛋白回收率和水解度的影响,确定了海参DPP-IV抑制肽的制备条件,并进一步测定了其分子量分布和总氨基酸组成,最后通过UPLC-MS/MS鉴定了其潜在的活性肽序列。结果发现,木瓜蛋白酶与复合蛋白酶1:1的复配酶解具有最佳的酶解效果,其产物的得率和DPP-IV抑制活性均最高,且在加酶量为干海参质量的1%,酶解时间为4 h时,海参酶解产物在终浓度为2 mg/mL时的DPP-IV抑制率为66.97%,蛋白回收率为76.25%,水解度为6.10%。酶解产物的分子量大都小于5000 u,且富含脯氨酸(Pro)和丙氨酸(Ala)等与抑制DPP-IV活性有关的氨基酸。将获得的酶解物中的肽段进行液质联用检测,并通过Mascot分析筛选得到28条具DPP-IV抑制肽的肽序列,分子量在500~1936 u。本实验结果为以海参为原料进行降血糖产品的开发奠定了基础。
Dipeptidyl-peptidase IV(DPP-IV)inhibitors are among the newest agents to regulate blood glucose levels by preventing degradation of the gut-derived hormone GLP-1.These inhibitors play an important role in regulating insulin secretion.In this study,DPP-IV inhibitory peptides were prepared from sea cucumber(Holotharia tubulosa)by enzymatic hydrolysis.The types of protease,their concentrations,and hydrolysis times were optimized to maximize DPP-IV inhibition,protein recovery(PR),and degree of hydrolysis(DH).In addition,the molecular weight distribution and the total amino acid composition of each hydrolysate were determined.DPP-IV inhibitory peptide sequences were identified by UPLC-MS/MS.Sea cucumber hydrolysates prepared with a 1:1 combination of papain and Protamex displayed optimal hydrolysis efficiency,and yielded products exhibiting the highest DPP-IV inhibition and PR.Optimal hydrolysis conditions were as follows:the total amount of Protamex added was 1%of the mass of the dry sea cucumber,and hydrolysis time was 4 h.Under these optimal conditions,DPP-IV inhibition,PR,and DH were 66.97%,76.25%,and 6.10%,respectively.Most peptide molecular weights in the optimal enzymatic hydrolysates were under 5000 u.The peptides were rich in Pro,Ala,and other amino acids related to DPP-IV inhibition.Peptides within the hydrolysates were identified by UPLC-MS/MS.Twenty eight of these polypeptides(with molecular weights ranging from 500 to 1936 u)were found by Mascot analysis to possess features typical of DPP-IV inhibitory peptides.The results of this study lay a foundation for development of hypoglycemic agents from sea cucumber.
作者
刘志彤
郑淋
王晨阳
赵谋明
LIU Zhi-tong;ZHENG Lin;WANG Chen-yang;ZHAO Mou-ming(College of Food Sciences and Food Technology,South China University of Technology,Guangzhou 510640,China)
出处
《现代食品科技》
EI
CAS
北大核心
2020年第8期166-174,共9页
Modern Food Science and Technology
基金
中央高校基本科研业务费专项资金(2018MS91)
广西创新驱动发展专项资金项目(桂科AA17204075)。
关键词
海参
DPP-IV抑制肽
制备
鉴定
sea cucumber
DPP-IV inhibitory peptides
preparation
identification
