Title : Identification of
N-linked glycoproteins in human milk by hydrophilic interaction liquid chromatography and mass spectrometry
Abstract :
- Breastfeeding is now generally recognized as a critical factor in protecting newborns against infections
- An important mechanism responsible for the antibacterial and antiviral effects of breast milk is the prevention of pathogen adhesion to host cell membranes mediated by a number of glycoconjugates, also including glycoproteins
- A number of approaches to describe the complexity of human milk proteome have provided only a partial characterization of restricted classes of N-linked glycoproteins
- To achieve this objective, profiling N-linked glycoproteins of human milk was performed by Hydrophilic Interaction LC (HILIC) and MS analysis
- Glycopeptides were selectively enriched from the protein tryptic digest of human milk samples
- Oligosaccharide-free peptides obtained by peptide N-glycosidase F ( PNGase F) treatment were characterized by a shotgun MS-based approach, allowing the identification of N-glycosylated sites localized on proteins
- Using this strategy, 32 different glycoproteins were identified and 63 N-glycosylated sites encrypted in them were located
- The glycoproteins include immunocompetent factors , membrane fat globule-associated proteins , enzymes involved in lipid degradation and cell differentiation, specific receptors , and other gene products with still unknown functions