中国毛虾二肽基肽酶-IV抑制肽的分离纯化与结构鉴定

Purification and identification of dipeptidyl peptidase-IV inhibitory peptide from Acetes chinensis hydrolysates

食源性二肽基肽酶-IV(dipeptidyl peptidase-IV,DPP-IV)抑制肽有助于调节机体血糖。为实现中国毛虾的高值化利用,从中国毛虾酶解产物中制备DPP-IV抑制肽,使用动物蛋白酶水解中国毛虾,以DPP-IV抑制率为评价指标分离多肽,并通过分子对接确定抑制作用位点。结果表明,酶解液经超滤、Sephadex G15和反相高效液相色谱分离纯化和液相-质谱联用技术鉴定后,得到了5条DPP-IV抑制肽,氨基酸序列分别为YGGQFPTRPD、PALPSIPH、IFTAPQVP、PAFPHPLP和LGDAPGEVP;其中PALPSIPH和PAFPHPLP对DPP-IV的抑制活性较高,二者的IC_(50)值分别为(2.68±0.06)和(1.61±0.06)mmol/mL。分子对接结果表明PALPSIPH和PAFPHPLP主要通过氢键与DPP-IV活性中心及其以外的位点相结合,以此达到抑制作用。该研究基于中国毛虾制备食源性DPP-IV抑制肽,为水产蛋白来源降血糖功能性食品开发利用和新型DPP-IV抑制肽的研究提供参考。

Food-derived dipeptidyl peptidase-IV(DPP-IV)inhibitory peptides can help regulate blood sugar in the body.To realize the high-value utilization of Acetes chinensis,DPP-IV inhibitory peptide was extracted from A.chinensis by animal protease.The peptides were separated according to the DPP-IV inhibition rate,and the inhibition sites were determined by molecular docking.The results showed that after the enzymatic hydrolysate was separated and purified by ultrafiltration,Sephadex G15,and reversed-phase high performance liquid chromatography,and identified by liquid chromatography-mass spectrometry,five DPP-IV inhibitory peptides were obtained,and their amino acid sequences were identified as YGGQFPTRPD,PALPSIPH,IFTAPQVP,PAFPHPLP,and LGDAPGEVP,respectively.Among those amino acid sequences,PALPSIPH and PAFPHPLP had higher inhibitory activities on DPP-IV,and their IC_(50) values were(2.68±0.06)and(1.61±0.06)mmol/mL,respectively.Molecular docking results showed that PALPSIPH and PAFPHPLP were mainly combined with the active center of DPP-IV and its other sites through hydrogen bonds,so as to achieve the inhibitory effect.The results provide a reference for the development and utilization of hypoglycemic functional foods from aquatic-protein source and the research of novel DPP-IV inhibitory peptides.