Structure of glycopeptides isolated from bovine milk component PP3.
The heat-stable acid-soluble phosphoglycoprotein component PP3 was isolated from the bovine milk proteose peptone fraction by concanavalin A affinity chromatography. Glycopeptides were released by pronase digestion of the milk component PP3 and were subsequently separated by high-pH anion-exchange chromatography on CarboPac PA-1. The primary structures of the glycan and peptide moieties of eight N-glycopeptides have been established by combining methylation analysis, mass spectrometry, 400-MHz 1H-NMR spectroscopy, and peptide sequence analysis. All the analyzed fractions contained biantennary N-acetyllactosamine-type carbohydrate chains, some of them with a GalNAc(beta 1-4)GlcNAc or a NeuAc(alpha 2-6)GalNAc(beta 1-4)GlcNAc group. This particular sequence did or did not replace the Gal(beta 1-4)GlcNAc group usually found in most N-linked glycans. Moreover, the sialylated Gal and GalNAc residues were only found on the Man(alpha 1-3) antenna.
Girardet
J M
JM
Laboratoire des BioSciences de l'Aliment, associé INRA, Université Henri Poincaré-Nancy 1, France.
Coddeville
B
B
Plancke
Y
Y
Strecker
G
G
Campagna
S
S
Spik
G
G
Linden
G
G
D000595:Amino Acid Sequence; D000606:Amino Sugars / Q000032:analysis / Q000737:chemistry; D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002364:Caseins / Q000737:chemistry* / Q000302:isolation & purification; D002417:Cattle; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D003208:Concanavalin A / Q000378:metabolism; D006020:Glycopeptides / Q000737:chemistry* / Q000302:isolation & purification; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008892:Milk / Q000737:chemistry*; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis / Q000737:chemistry; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification; D016415:Sequence Alignment
D000606:Amino Sugars; D002364:Caseins; D006020:Glycopeptides; D006023:Glycoproteins; D009005:Monosaccharides; D009844:Oligosaccharides; C085522:PP3 protein, Bos taurus; D010446:Peptide Fragments; D003208:Concanavalin A; C000458:N-acetyllactosamine