牛初乳小分子多肽的分离及其抗菌作用的研究

Preparation and Antibacterial Function of Bioactive Peptides Derived from Bovine Colostrum

为了探讨牛初乳中小分子多肽的抗菌活性及组分特征,本研究首先以新鲜牛初乳为原料,通过分离收集不同区段的蛋白片段加以冻干,然后利用3 ku以下蛋白片段通过观察其对96孔板中细菌生长曲线的影响来进行抑菌实验,随后采用葡聚糖凝胶色谱联合反相高效液相色谱的方法对3 ku以下的牛初乳组分进一步分离纯化,最后将分离得到的F3组分进行多肽/蛋白质N端测序分析。研究发现3 ku以下蛋白片段对大肠杆菌的生长具有显著的抑制作用,而且随着蛋白片段浓度的增加,抑菌效果更为明显。N端测序结果表明,牛初乳中3 ku以下成分的氨基酸序列为NH2-Y-Q-E-P-V-L-G-P-V,该序列经网上相关报道比对分析为牛乳中的β-酪蛋白片段,为牛初乳的研究和利用开发提供了一定的实验依据。

To investigate antibacterial activity and composition characteristics of the corresponding bioactive peptides in bovine colostrum,different protein fragments were isolated from fresh bovine colostrum,and underwent freeze-drying.Protein fragments under 3 ku were observed for its antibacterial effect by its influence on bacterial growth curve in 96 well plates.Then through dextran gel chromatography combined wirh reversed-phase high performance liquid chromatography,3 ku bovine colostrum composition underwent further purification,and finally the isolated F3 components were investigated through N-terminal sequencing analysis.It was found that protein fragments below3 ku had a significant inhibitory effect on the growth of Escherichia coli,and the inhibitory effect was more obvious with the increase of protein fragment concentration.N-terminal sequencing analysis determined that the amino acid sequence of the 3 ku components in bovine colostrum was NH2-Y-Q-E-P-V-L-G-P-V,and the sequence was confirmed as casein of bovine colostrum through comparison with relevant online reports,These results provide data support for further research and application of bovine colostrum.