Characterization of the milk fat globule membrane proteome in colostrum and mature milk of Xinong Saanen goats.

Xinong Saanen goat milk is a major source of milk in the Chinese dairy industry. Milk fat globule membrane (MFGM) proteomes of goat colostrum and mature milk were analyzed and compared using proteomic technology. A total of 543 and 585 proteins were identified in goat colostrum and mature milk, respectively. Functional category analyses revealed that most of the MFGM proteins in both colostrum and mature milk were related to phosphoprotein and acetylation. The biological process of translation, cellular component of extracellular exosome, and molecular function of poly(A) RNA binding were the main gene ontology annotations of both colostrum and mature milk. Pathways associated with disease and genetic information processing involved large number of proteins in colostrum and mature milk, and more metabolism-related pathways were observed in mature milk. Protein-protein interaction network analyses showed that ribosome was abundant in both colostrum and mature milk. Colostrum showed more functions associated with protein processing in the endoplasmic reticulum, whereas mature milk had more oxidative phosphorylation functions. The results could provide further understanding of the unique biological properties of MFGM proteins of goat colostrum and mature milk.