The aim of this study was to identify dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from salmon skin collagen hydrolysate, and to evaluate the possible inhibition mechanism of DPP-IV and peptide. Salmon skin collagen was hydrolyzed by pepsin, trypsin, papain, or Alcalase 2.4 L, separately. Trypsin hydrolysate (10 mg/mL) showed the highest inhibitory activity of 66.12 ± 0.68%. The hydrolysate was separated into three fractions by ultrafiltration, and the inhibitory IC₅₀ of M1 (molecular weight < 3 kDa) was 1.54 ± 0.06 mg/mL. M1 was separated by gel chromatography and RP-HPLC; A10 was the highest inhibitory fraction in the 12 fractions, i.e., IC₅₀ was 0.79 ± 0.13 mg/mL. A novel peptide LDKVFR with the IC₅₀ value of 0.1 ± 0.03 mg/mL (128.71 μM) was identified from A10. Molecular docking revealed that six hydrogen bonds and eight hydrophobic interactions between LDKVFR and DPP-IV were contributed to DPP-IV inhibition.

这项研究的目的是从鲑鱼皮肤胶原蛋白水解物中鉴定出二肽基肽酶IV（DPP-IV）抑制肽，并评估DPP-IV和肽的可能抑制机制。鲑鱼皮肤胶原分别被胃蛋白酶，胰蛋白酶，木瓜蛋白酶或Alcalase 2.4 L水解。胰蛋白酶水解产物（10 mg / mL）显示出最高的抑制活性，为66.12±0.68％。通过超滤将水解产物分为三部分，M1（分子量<3 kDa）的抑制IC ₅₀为1.54±0.06 mg / mL。通过凝胶色谱法和RP-HPLC分离M1。在12个馏分中，A10的抑制率最高，即IC ₅₀为0.79±0.13 mg / mL。具有IC _50的新型肽LDKVFR从A10鉴定出0.1±0.03 mg / mL（128.71μM）的值。分子对接揭示了LDKVFR和DPP-IV之间的六个氢键和八个疏水相互作用对DPP-IV的抑制有贡献。