【作者】 谢德伟； 谢静莉； 魏东芝；

【Author】 Xie Dewei;Xie Jingli;Wei Dongzhi;State Key Laboratory of Bioreactor Engineering,School of Biotechnology,East China University of Science and Technology;

【机构】 华东理工大学生物反应器国家重点实验室生物工程学院；

【摘要】 作为牛乳乳清中含量第二的蛋白,α-乳白蛋白(alpha-lactalbumin,α-La)在食品工业中有广泛应用。本研究通过模拟胃肠道水解α-La,测定其水解产物的各种生物活性,并筛选具有良好生物活性的肽段。采用胃蛋白酶和胰酶进行模拟胃肠道水解后,5 mg/mL的水解液对血管紧张素转化酶(Angiotensin I converting enzyme,ACE;EC3.4.15.1)的抑制率达85.7%;对ABTS自由基、羟自由基清除率分别为75.2%与50.4%;对二肽基肽酶(Dipeptidyl peptidase,DPP-IV;EC 3.4.14.5)及黄嘌呤氧化酶(Xanthine oxidase,XO;EC 1.1.3.22)抑制率分别为55.6%与52.7%。采用超滤和葡聚糖凝胶色谱对分子量小于3 KDa的水解产物进行分离纯化,共得到五个组分。不同组分水解产物的生物活性都较水解液有大幅提升,其中组分F4、F5(5 mg/mL)对ABTS自由基的清除率都超过90%,F5组分的XO抑制活性可达到90%。可见α-La经胃肠道消化可产生高活性生物活性肽。此外,对α-La进行计算机辅助的虚拟胃肠道水解得到肽库,与模拟胃肠道水解产物的NanoLC-QTOF-MS/MS联用仪鉴定结果比较,分子量在500Da到3 KDa之间肽段的重合率可达87.9%,表明计算机辅助的虚拟水解可以作为一种高效准确的肽库构建手段。更多还原

【Abstract】 Alpha-lactalbumin(α-La),of which the content in milk whey protein is the second-highest,is widely used in the food industry.The aim of this study is to discover the potential α-La for bioactive peptides formation through the gastrointestinal hydrolysis.Alpha-La was simulated gastrointestinal hydrolyzed with pepsin and pancreatin.For 5 mg/mL hydrolysate,the inhibition of angiotensin I converting enzyme(ACE;EC 3.4.15.1) was 85.7%;and the ABTS and DPPH scavenging rates were 75.2% and 50.4%,respectively;and the inhibition of dipeptidyl peptidase(DPP-IV;EC3.4.14.5) and xanthine oxidase(XO;EC 1.1.3.22) were 55.6% and 52.7%.After the hydrolysate was separated by ultrafiltration and dextran gel chromatography,the fraction less than 3 KDa is divided into 5 portions,and the activity of the portions was greatly improved.ABTS scavenging rates of F4 and F5(5 mg/mL) were more than 90%,and the XO inhibitory activity of the F5 reached 90%.The results suggested that α-La can generate bioactive peptides by gastrointestinal digestion.In addition,a peptide library was obtained by computer-aided virtual gastrointestinal hydrolysis of α-La,which was compared with the peptides identified by NanoLC-QTOF-MS/MS.The results indicated that the coincidence for both methods of peptide formation was 87.9% when the molecular weight of peptides was between 500 Da and 3 KDa.Accordingly,the computer-aided approach is an efficient and accurate means to establish peptide library.更多还原