Structural studies on a sulphated glycoprotein preparation isolated from human saliva.

The identity of the sulphated component in a high-molecular-weight glycoprotein preparation (GP) from human whole saliva was investigated. A t0.5 of 96 min for inorganic sulphate release in 0.25 M HCl indicated the presence of O-substituted sulphate, probably associated with hydroxyl groups of sugar residues. This possible association of ester was also inferred from infra-red data of the intact GP, where major absorption bands were detected at 1230-1250 and 828 cm-1. Further a sulphated-monosaccharide derivative was released during acid hydrolysis in 0.1 M HCl at 100 degrees C for 75 min and isolated by gel-filtration on Sephadex G-15. This derivative was separated from a range of non-sulphated sugars by thin-layer chromatography in various solvent systems and possessed the chromatographic characteristics of N-acetylgalactosamine-6-O-sulphate.