Isolation and characterization of a sialo-glycopeptide from buffalo colostrum.

A sialoglycopeptide was isolated from buffalo colostrum in pure form by chromatography on Sephadex G-25 and QAE-Sephadex A-25. This was found to be homogeneous by cellulose acetate membrane electrophoresis and reverse phase HPLC. It consisted of fucose, galactose, mannose, N-acetyl glucosamine and N-acetyl neuraminic acid in the ratio 1:2:3:4:1, and aspartic acid, serine, threonine, proline and glutamic acid were the major amino acids. Glycine was identified as the N-terminal amino acid residue. The structure elucidation of the carbohydrate moiety was carried out by methylation analysis, mass spectrometry. 1H-NMR spectroscopy and the probable structure was revealed to be that of a complex biantennary type.