Protein containing one or more covalently linked and usually sulfated glycosaminoglycans, (e.g., chondroitin sulfate, dermatan sulfate, heparan sulfate, heparin, keratan sulfate). Glycosaminoglycans are polysaccharides made of repeating disaccharides (usually 40-100 times), which consist of uronic acid (or galactose) and hexosamines. Aggrecan, for example, is the major component in articular cartilage.
