鲟鱼皮中二肽基肽酶-IV抑制肽的分离纯化与鉴定

为从鲟鱼皮中分离提取出二肽基肽酶-IV（dipeptidyl peptidase IV，DPP-IV）抑制活性肽，以鲟鱼皮胶原蛋白为主要材料，利用蛋白酶进行酶解，以DPP-IV抑制率为主要考察指标，在单因素试验的基础上，进一步利用响应面法优化了鲟鱼鱼皮中DPP-IV抑制肽的制备工艺条件，确定最佳酶解条件为：酶解温度50?℃、料液比1∶100（g/mL）、pH?6.12、加酶量10?170.35?U/g、酶解时间12.12?h。在此基础上，通过超滤、凝胶层析及反相高效液相色谱的方法对酶解产物进行分离纯化；采用液相色谱-串联质谱法对多肽进行鉴定，结果显示纯化后具有DPP-IV抑制活性肽氨基酸组成为：甘氨酸-脯氨酸-丝氨酸-甘氨酸-亮氨酸-天冬氨酸-甘氨酸-丙氨酸-赖氨酸（GPSGLDGAK），IC50值可达（61.27±1.16）μmol/L。本研究结果可为利用鲟鱼皮生产新型的生物活性成分提供参考。

Purification and Identification of Dipeptidyl Peptidase IV Inhibitory Peptide from Sturgeon Skin Collagen

In order to prepare dipeptidyl peptidase IV (DPP-IV) inhibitory peptide, sturgeon skin collagen was hydrolyzed by protease. A combination of one-factor-at-a-time method and response surface methodology was used optimize the preparation conditions based on percentage of DPP-IV inhibition. The optimal enzymatic hydrolysis conditions were determined as follows: temperature 50 ℃, solid-to-liquid ratio 1:100 (g/mL), pH 6.12, enzyme dosage 10 170.35 U/g, and enzymatic hydrolysis time 12.12 h. The hydrolysate prepared under the optimized conditions was separated and purified by sequential ultrafiltration, gel filtration chromatography and reverse-phase high performance liquid chromatography (RP-HPLC). As identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), the amino acid composition of the purified peptide with DPP-IV inhibitory activity was GPSGLDGAK, and its half-maximum inhibitory concentration (IC50) value was (61.27 ± 1.16) μmol/L. The results of this study can provide a reference for the production of new bioactive components from sturgeon skin.