Variation in both proteome and N-glycoproteome of goat MFGM over lactation

Glycoproteins have been associated in numerous biological functions and has gained much interest for research. This study comprehensively compare proteome and N-glycoproteome of goat milk fat globule membrane (MFGM) over lactation by N-glycosylated peptides enrichment combined with nanospray LC-MS/MS on Q Exactive™ HF plus mass spectrometer. A total of 1639 proteins and 557 N-glycoproteins were identified in goat MFGM fraction. There were 232 proteins and 106 N-glycoproteins were significantly different in goat MFGM between colostrum and mature milk. Most of the differentially expressed proteins were associated with protein processing in endoplasmic reticulum and epstein-barr virus infection, while majority of significantly different N-glycoproteins were engaged in complement and coagulation cascades and lysosome, etc. Furthermore, MFGM proteins were found to be involved in PI3K-Akt signaling pathway, suggesting the potential hypoglycemic effect of goat MFGM protein. Both proteome and N-glycoproteins of caprine MFGM changes with the increase of lactation. The study provides the real changes of N-glycoproteins and insights into biological function of MFGM protein.