【摘要】 通过从分化成熟的人克隆结肠腺癌细胞（Caco-2细胞）中提取二肽基肽酶-Ⅳ（DPP-Ⅳ）建立体外筛选DPP-Ⅳ抑制剂的模型,用Ile-Pro-Ile（IPI）作为阳性对照测定其半抑制质量浓度(IC₅₀)评价该模型,并测定3种来源于酪蛋白的四肽Leu-Pro-Leu-Pro（LPLP）、Gln-Glu-Pro-Val（QEPV）和Asp-Gln-Leu-Gln（DELQ）的抑制率,研究了DPP-Ⅳ抑制肽的抑制类型和复合抑制作用。实验结果表明:IPI的IC₅₀为（31.51±1.51）μg/m L,与文献报道的相近,证明该模型可以应用于DPP-Ⅳ抑制剂的筛选;LPLP的IC₅₀为（0.84±0.06）mg/m L,QEPV的IC₅₀为（14.45±1.07）mg/m L而DELQ的IC₅₀大于100 mg/m L,即LPLP和QEPV具有一定的抑制作用;LPLP和QEPV的作用均为非竞争性机制,并且两种多肽联合对DPP-Ⅳ抑制作用为协同抑制作用。更多还原

【Abstract】 The model of DPP-Ⅳ inhibitor was established by extracting DPP-Ⅳ from Caco-2 cells. Ile-Pro-Ile（IPI）, a positive control,was used to evaluate the selected model. The half concentration(IC₅₀) of three casein-derived bioactive peptides, Leu-Pro-Leu-Pro（LPLP）, Gln-Glu-Pro-Val（QEPV） and Asp-Gln-Leu-Gln（DELQ）, were studied. The DPP-Ⅳ inhibitory types of three peptides and the inhibition rate of complex peptides were studied. The results showed that the IC₅₀ of LPLP, QEPV and DELQ was 0.84±0.06 mg/m L,14.45±1.07 mg/m L and more than 100 mg/m L respectively. The DPP-Ⅳ inhibitory type of LPLP and QEPV was noncompetitive mechanisms. The combination of the LPLP and QEPV to DPP-Ⅳ inhibition was synergistic inhibition.更多还原