glycosaminoglycan

glycosaminoglycan A negatively charged chain of polysaccharides (modified sugars) that is composed of repeating disaccharide units. Abbreviated GAG. Important GAGs in the human body include chondroitin sulfate, dermatan sulfate, heparan sulfate, heparin, hyaluronate, and keratan sulfate. GAGs are involved as lubricants and components of bone, cartilage, blood vessels, and certain types of cells. Also known as mucopolysaccharides.