The aim of this study is to explore differences in the peptidomics of Saccharomyces pastorianus protein hydrolysates treated with different enzymes. Briefly, differences in the peptide fingerprints and active peptides of neutral protease/papain-hydrolyzed S. pastorianus were analyzed using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) combined with PEAKS Online 1.7 analysis software, Peptide Ranker, and the BIOPEP database. Compared to traditional databases, the PEAKS Online uses de novo sequencing for analysis to obtain oligopeptides smaller than pentapeptides. It provides more comprehensive data of the peptide sample. In this study, enzymatic hydrolysates of S. pastorianus protein were prepared under the optimum conditions of neutral protease and papain respectively. In total, 7221 and 7062 polypeptides were identified in the hydrolysates of neutral protease and papain, respectively; among these polypeptides, 980 were common to the two enzymes. The 6241 and 6082 unique peptides found in the hydrolysates of neutral protease and papain, respectively, indicated that the peptide fingerprints of the two hydrolysates are quite different. Peptide Ranker predicted that 3013 (41.73%) and 3095 (43.83%) peptides were potentially bioactive in the hydrolysates of neutral protease and papain, respectively. According to the BIOPEP database, neutral protease and papain contained 295 and 357 active peptides, respectively; these peptides were mainly composed of angiotensin converting enzyme (ACE) inhibitors and dipeptidyl peptidase IV inhibitors and antioxidant peptides. The number of active peptides in the hydrolysate of papain was higher than that in the hydrolysate of neutral protease, but the total ion intensity of active peptides in the former was lower than that in the latter. This study revealed the influence of protease type on the composition of enzymatic hydrolysates from S. pastorianus protein. The above results provide a reference for the development of functional products of S. pastorianus protein peptides and the high-value utilization of yeast resources.
采用超高效液相色谱-高分辨质谱(UHPLC-HRMS)联用技术,结合PEAKS Online 1.7肽组学分析软件和Peptide Ranker、BIOPEP数据库,分析比较了啤酒酵母的中性蛋白酶和木瓜蛋白酶酶解液的肽指纹谱图和活性肽差异,旨在探究不同酶处理的啤酒酵母蛋白酶解液的肽组学差异。PEAKS Online采用de novo测序,相较于传统数据库,更全面地分析得到五肽及其以下寡肽,使样品中的肽段数据更加完整。实验在中性蛋白酶和木瓜蛋白酶的最佳酶解工艺下制备得到啤酒酵母蛋白酶解液,然后进行UHPLC-HRMS分离鉴定及数据检索和分析。研究结果表明,中性蛋白酶、木瓜蛋白酶的酶解产物中分别鉴定出7221和7062条多肽,其中共有肽为980条,而特有肽分别为6241条和6082条,说明两种不同蛋白酶降解产物的肽指纹谱图有很大的差异。使用Peptide Ranker预测出中性蛋白酶和木瓜蛋白酶的酶解产物中有3013和3095条肽为潜在活性肽,其占比分别为41.73%和43.83%。搜索BIOPEP数据库发现,中性蛋白酶和木瓜蛋白酶的酶解产物中有295条和357条活性肽,其中主要是血管紧张素转化酶(ACE)抑制肽、二肽基肽酶Ⅳ抑制肽和抗氧化肽。比较发现,木瓜蛋白酶产物中活性肽数量高于中性蛋白酶产物,但是活性肽的相对含量低于中性蛋白酶产物,本研究更好地揭示了不同蛋白酶对啤酒酵母蛋白肽产品组成的影响。上述结果为啤酒酵母蛋白肽的功能产品开发和啤酒酵母资源的高值化利用提供了参考。
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