Glycoproteomics of milk: differences in sugar epitopes on human and bovine milk fat globule membranes
Wilson, Nicole L.
Robinson, Leanne J.
Packer, Nicolle H.
Karlsson, Niclas G.
MetadataShow full item record
This item's downloads: 0 (view details)
Cited 77 times in Scopus (view citations)
Wilson, Nicole L. Robinson, Leanne J.; Donnet, Anne; Bovetto, Lionel; Packer, Nicolle H.; Karlsson, Niclas G. (2008). Glycoproteomics of milk: differences in sugar epitopes on human and bovine milk fat globule membranes. Journal of Proteome Research 7 (9), 3687-3696
Oligosaccharides from human and bovine milk fat globule membranes were analyzed by LC-MS and LC-MS/MS. Global release of N-linked and O-linked oligosaccharides showed both to be highly sialylated, with bovine peak-lactating milk O-linked oligosaccharides presenting as mono- and disialylated core 1 oligosaccharides (Gal beta 1-3GalNAcol), while human milk had core type 2 oligosaccharides (Gal beta 1-3(GlcNAc beta 1-6) GalNAcol) with sialylation on the C-3 branch. The C-6 branch of these structures was extended with branched and unbranched N-acetyllactosamine units terminating in blood group H and Lewis type epitopes. These epitopes were also presented on the reducing terminus of the human, but not the bovine, N-linked oligosaccharides. The O-linked structures were found to be attached to the high molecular mass mucins isolated by agarose-polyacrylamide composite gel electrophoresis, where MUC1 and MUC4 were present. Analysis of bovine colostrum showed that O-linked core 2 oligosaccharides are present at the early stage (3 days after birth) but are down-regulated as lactation develops. This data indicates that human milk may provide different innate immune protection against pathogens compared to bovine milk, as evidenced by the presence of Lewis b epitope, a target for the Helicobacter pylori bacteria, on human, but not bovine, milk fat globule membrane mucins. In addition, non-mucin-type O-linked fucosylated oligosaccharides were found (NeuAc-Gal-GlcNAc1-3Fuc-ol in bovine milk and Gal-GlcNAc1-3Fuc-ol in human milk). The O-linked fucose structure in human milk is the first to our knowledge to be found on high molecular mass mucin-type molecules.