Differential proteomic analysis of milk fat globule membrane proteins in human and bovine colostrum by iTRAQ-coupled LC-MS/MS

Milk fat globule membrane (MFGM) proteins have important biological functions, such as anticancer properties, preventing Helicobacter pylori infection, and immune functions. However, the full range of colostrum MFGM proteins has not completely identified. In this study, extracted colostrum MFGM proteins were identified and quantified using the isobaric tags for relative and absolute quantitation proteomic method. A total of 411 human and bovine colostrum MFGM proteins were identified and quantified. These MFGM proteins were classified according to gene ontology annotation. The major biological processes involved were response to stimulus, representing 19 % of total proteins; establishment of localization (18 %); and cellular component organization (17 %). The most prevalent cellular components were intracellular representing 19 %, and intracellular part represented 18 %. The most prevalent molecular function was protein binding (46 %). Hierarchical clustering was used for the quantitative analysis of colostrum MFGM levels in humans and bovines. Furthermore, one-factor analysis of variance identified 26 differentially expressed proteins. The differentially expressed proteins were involved in three major pathways: calcium signaling pathway, phagosome, and FcγR-mediated phagocytosis. This study examined the expression changes and functional differences of colostrum MFGM proteins between humans and bovines to provide useful information and potential research directions for the dairy industry.