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D...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。展开更多
Glucagon-like peptide-1（GLP-1） is an endogenous insulinotropic hormone with excellent blood glucose-lowering activity, however, it is rapidly inactivated in the plasma mainly by dipeptidyl peptidase IV（DPP-IV）. To...Glucagon-like peptide-1（GLP-1） is an endogenous insulinotropic hormone with excellent blood glucose-lowering activity, however, it is rapidly inactivated in the plasma mainly by dipeptidyl peptidase IV（DPP-IV）. To overcome this problem, various N-terminal modifications of GLP-1 have been performed to prolong the in vivo biological activity, by improving the DPP-IV resistance while retaining receptor affinity and receptor activation. These studies have included modifications of His7, Ala8 or Glu9 at the N-terminus of GLP-1 and some other modifications. Among them, Ala8 substitutions with glycine（Gly8） and α-aminoisobutyric acid（Aib8） have been clinically applied in the development of diabetic therapy, such as Exenatide, Semaglutide, Albiglutide and Taspoglutide. In this review, we introduce N-terminal modifications of GLP-1 that have been reported, and discuss their potential and challenges for the treatment of type 2 diabetes.展开更多
文摘Glucagon-like peptide-1（GLP-1） is an endogenous insulinotropic hormone with excellent blood glucose-lowering activity, however, it is rapidly inactivated in the plasma mainly by dipeptidyl peptidase IV（DPP-IV）. To overcome this problem, various N-terminal modifications of GLP-1 have been performed to prolong the in vivo biological activity, by improving the DPP-IV resistance while retaining receptor affinity and receptor activation. These studies have included modifications of His7, Ala8 or Glu9 at the N-terminus of GLP-1 and some other modifications. Among them, Ala8 substitutions with glycine（Gly8） and α-aminoisobutyric acid（Aib8） have been clinically applied in the development of diabetic therapy, such as Exenatide, Semaglutide, Albiglutide and Taspoglutide. In this review, we introduce N-terminal modifications of GLP-1 that have been reported, and discuss their potential and challenges for the treatment of type 2 diabetes.
