Beta-elimination for release of O-linked glycosaminoglycans from proteoglycans.

O-linked glycosaminoglycan (GAG) chains in proteoglycans are readily released from their core proteins by treatment with alkali at room temperature. This beta-elimination is the same type of reaction as that for releasing O-linked oligosaccharides from their core proteins. Under the reaction conditions described here, N-linked oligosaccharides remain attached to the core protein, but any O-linked oligosaccharides will be released along with the GAG chains. The procedure can be used to isolate the free GAG chains, the free O-linked oligosaccharides, and the core protein (which will still have any N-linked oligosaccharides that were originally present).