牛初乳与牛乳中乳清蛋白质组成及功能的对比分析

乳清富含多种功能特性和生物活性的蛋白质,本研究利用SDS-PAGE电泳将牛初乳与牛乳中乳清蛋白质的组成部分进行分离鉴定,发现牛初乳与牛乳中乳清蛋白质的组成存在较大的差异,且在牛初乳乳清中鉴定出290种蛋白,牛乳乳清中鉴定出325种蛋白。由GO功能注释分析发现,在生物过程中,牛初乳乳清蛋白在细胞定位建立和细胞定位中的作用略高于牛乳乳清蛋白。在分子功能上酶抑制活性作用是牛初乳乳清蛋白和牛乳中乳清蛋白的主要分子功能。在细胞组成上牛初乳乳清蛋白参与较多的是细胞外部分和细胞外空隙,与牛乳乳清蛋白相比参与的细胞组成大体相同。通过KEGG代谢通路分析可知,牛初乳和牛乳乳清蛋白均参与过补体及凝血级联反应通路。对牛初乳乳清蛋白组成进行研究,不仅能够增加牛初乳的利用率,并且为日后以乳清蛋白作为原料生产乳制品提供理论依据。

Comparative Analysis of Composition and Function of Whey Proteins in Bovine Colostrum and Bovine Milk

Whey contains proteins with a variety of functional properties and biological activities. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to separate the whey proteins in bovine colostrum and bovine milk. The results showed significant differences in the whey protein composition between colostrum and normal milk, and 290 and 325 types of proteins were identified in whey from bovine colostrum and bovine milk, respectively. According to the gene ontology (GO) annotations, bovine colostrum whey proteins exhibited a slightly higher impact on the establishment of cellular localization and the cellular localization than normal milk whey proteins. Enzyme inhibition was the main molecular function of whey proteins from bovine colostrum and normal milk. Regarding cellular composition, bovine colostrum whey proteins were involved in the extracellular region and extracellular space, and bovine milk whey proteins showed a similar result. The Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis suggested that whey proteins from both bovine colostrum and normal milk were involved in the reaction pathways of coagulation and complement cascades. This study of the whey protein composition in bovine colostrum can not only promote the utilization of bovine colostrum, but also provide theoretical foundations for future production of dairy products using whey protein as a raw material.