Keratan sulfate-rich peptides were isolated after digestion of proteoglycans from bovine nasal cartilage and bovine nucleus pulposus with chondroitinase ABC, trypsin and chymotrypsin. The keratan sulfate enriched peptides from nucleus pulposus were larger than those from nasal cartilage. Keratan sulfate chains were isolated after treatment of the keratan sulfate-rich peptides under alkaline, reductive conditions. Proteoglycans from nucleus pulposus contain longer keratan sulfate chains, as is shown primarily by gel chromatography of the keratan sulfate-rich peptides and the keratan sulfate chains, but also from end-group analyses of the keratan sulfate chains.