College of Food Science &Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China.
College of Food Science &Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China.
Food Res Int. 2021 Apr;142:110201. doi: 10.1016/j.foodres.2021.110201. Epub 2021 Feb 10.
Chinese Rushan and Naizha, the traditional acid coagulated cheese types produced from cow and yak milk, respectively, have been consumed for more than thousands of years. In this study, we aimed to characterise peptides of Rushan and Naizha in simulated in vitro gastrointestinal digestion using label-free based peptidomic. The identified peptide sequences were subjected to BIOPEP database driven bioactivity search. In total, 309 and 225 peptides were identified from Rushan and Naizha cheese, respectively, corresponding to 20 protein annotations. Analysis of label-free quantification found different protein digestibility, where casein was the primary source of peptides in Rushan, among which 62% represented β-casein by peptide count. The release of peptides was concentrated in specific residues 145-155 of β-casein in Rushan. In contrast, κ-casein and 7 minor milk proteins were dominant in digestion of Naizha cheese (p < 0.05). In particular, there were 11 peptides from digestion that were exact matches in databases to sequences with immunomodulatory, antibacterial, ACE-inhibition, DPP IV inhibition and antioxidant activities. Four novel angiotensin I-converting enzyme inhibitory (ACEI) activities peptides (YPFPGPIH, LKNWGEGW, RELEEIR, and HPHPHLS) were explored using molecular docking, chemically synthesized, and in vitro ACEI activity. The peptides had lower estimated free energy values (-5.34 to -7.66 kcal/mol), and exhibited the lowest IC value of 109.5, 77.7, 196.6, and 64.30 μM, respectively. Our study is the most comprehensive peptidomic analysis of Chinese Rushan and Naizha cheese to date.
中国传统的酸凝奶酪有两种，分别是牛乳制成的如什山奶酪和牦牛奶制成的奶渣，这两种奶酪已经被食用了数千年。在这项研究中，我们旨在使用无标记肽组学方法来研究如什山和奶渣奶酪在模拟的胃肠道消化过程中的肽特性。所鉴定的肽序列被提交到 BIOPEP 数据库进行生物活性搜索。从如什山奶酪和奶渣奶酪中分别鉴定出 309 种和 225 种肽，分别对应 20 种蛋白质注释。无标记定量分析发现不同的蛋白质消化率，其中酪蛋白是如什山奶酪中肽的主要来源，其中 62%的肽由β-酪蛋白组成，按肽计数。肽的释放集中在如什山奶酪β-酪蛋白的特定残基 145-155 处。相比之下，κ-酪蛋白和 7 种次要乳蛋白在奶渣奶酪消化中占主导地位（p<0.05）。特别是，有 11 种肽在数据库中与具有免疫调节、抗菌、ACE 抑制、DPP IV 抑制和抗氧化活性的序列完全匹配。使用分子对接、化学合成和体外 ACEI 活性对 4 种新的血管紧张素转化酶抑制（ACEI）活性肽（YPFPGPIH、LKNWGEGW、RELEEIR 和 HPHPHLS）进行了探索。这些肽的估计自由能值较低（-5.34 至-7.66 kcal/mol），体外 ACEI 活性的 IC 值最低，分别为 109.5、77.7、196.6 和 64.30 μM。我们的研究是迄今为止对中国如什山奶酪和奶渣奶酪最全面的肽组学分析。
