Key Laboratory of Dairy Science, Northeast Agricultural University, College of Food Science, Harbin 150030, China.
Harbin Veterinary Research Institute, CAAS, Harbin 150001, China.
Molecules. 2018 May 19;23(5):1220. doi: 10.3390/molecules23051220.
The primary objective of this study was to improve our understanding of the antimicrobial mechanism of protein-derived peptides and to provide evidence for protein-derived peptides as food bio-preservatives by examining the antimicrobial activities, low cytotoxicity, stabilities, and mechanism of Cp1 (LRLKKYKVPQL). In this study, the protein-derived peptide Cp1 was synthesized from bovine α-casein, and its potential use as a food biopreservative was indicated by the higher cell selectivity shown by 11-residue peptide towards bacterial cells than human RBCs. It also showed broad-spectrum antimicrobial activity, with minimum inhibitory concentrations (MICs) of 64⁻640 μM against both gram-positive and gram-negative bacteria. The peptide had low hemolytic activity (23.54%, 512 μM) as well as cytotoxicity. The results of fluorescence spectroscopy, flow cytometry, and electron microscopy experiments indicated that Cp1 exerted its activity by permeabilizing the microbial membrane and destroying cell membrane integrity. We found that Cp1 had broad-spectrum antimicrobial activity, low hemolytic activity, and cytotoxicity. The results also revealed that Cp1 could cause cell death by permeabilizing the cell membrane and disrupting membrane integrity. Overall, the findings presented in this study improve our understanding of the antimicrobial potency of Cp1 and provided evidence of the antimicrobial mechanisms of Cp1. The peptide Cp1 could have potential applications as a food biopreservative.
本研究的主要目的是提高我们对蛋白衍生肽的抗菌机制的理解，并通过研究抗菌活性、低细胞毒性、稳定性和 Cp1（LRLKKYKVPQL）的机制，为蛋白衍生肽作为食品生物防腐剂提供证据。在本研究中，从牛α-酪蛋白中合成了蛋白衍生肽 Cp1，11 个氨基酸肽对细菌细胞的细胞选择性高于人 RBCs，表明其可能作为食品生物防腐剂使用。它还表现出广谱的抗菌活性，对革兰氏阳性和革兰氏阴性细菌的最小抑菌浓度（MIC）分别为 64⁻640 μM。该肽的溶血活性（23.54%，512 μM）和细胞毒性均较低。荧光光谱、流式细胞术和电子显微镜实验的结果表明，Cp1 通过破坏微生物膜的通透性来发挥其活性并破坏细胞膜的完整性。我们发现 Cp1 具有广谱抗菌活性、低溶血活性和细胞毒性。结果还表明，Cp1 可以通过破坏细胞膜的通透性导致细胞死亡。总体而言，本研究的结果提高了我们对 Cp1 的抗菌效力的理解，并提供了 Cp1 的抗菌机制的证据。肽 Cp1 可能具有作为食品生物防腐剂的应用潜力。
