牛初乳与牛常乳乳脂肪球膜中丰度差异蛋白的表征与分析

为阐明不同泌乳期间牛乳乳脂肪球膜蛋白的差异，选定牛初乳和牛常乳中的乳脂肪球膜蛋白作为研究对象，利用定量蛋白质组学技术对其中的蛋白质进行表征，并对两组间的丰度差异蛋白进行筛选及生物信息学分析。本研究共鉴定到763 种蛋白，其中197 种为两组共有蛋白，进一步从其中筛选出80 种丰度差异蛋白，包括41 种上调蛋白和39 种下调蛋白（牛初乳/牛常乳）。对上述丰度差异蛋白进行生物信息学分析发现，这些蛋白参与的主要细胞组分为细胞外泌体、细胞外空间、细胞外区域等，参与的主要代谢通路为代谢途径、嘌呤代谢、苯丙氨酸代谢、酪氨酸代谢、丙酮酸代谢、糖酵解/糖异生等，并进一步筛选出31 种与其他蛋白存在相互作用的关键蛋白，包括结合珠蛋白、2-磷酸-D-甘油酸水解酶等。研究结果将有助于了解泌乳期间乳蛋白成分的差异及其功能性，为牛乳制品的精深加工奠定基础。

Characterization and Analysis of Differentially Abundant Proteins in Milk Fat Globule Membranes between Bovine Colostrum and Mature Milk

In order to clarify the differences in bovine milk fat globular membrane proteins during different lactation periods, milk fat globular membrane proteins in bovine colostrum and mature milk were characterized by quantitative proteomics. The differentially abundant proteins between the two groups were identified and analyzed by bioinformatics. A total of 763 proteins were identified in this study, of which 197 were shared by the two groups. Meanwhile, 80 differentially abundant proteins were further identified, of which, 41 were up-regulated while the rest were down-regulated (bovine colostrum/mature milk). Bioinformatics analysis of the differentially abundant proteins demonstrated that the main cellular components involving these proteins were exosomes, extracellular space, and extracellular regions. The main metabolic pathways involving them were metabolic pathways, purine metabolism, phenylalanine metabolism, tyrosine metabolism, pyruvate metabolism, and glycolysis/gluconeogenesis. Furthermore, 31 key proteins that could interact with other proteins were identified, including haptoglobin and 2-phospho-D-glycerol acid hydrolase. These findings will help to understand the changes of milk protein composition and its functionality during lactation, and lay the foundation for the deep processing of bovine dairy products.