Chondroitin sulfate (CS) is a kind of sugar-amine oligosaccharide, which is covalent-linked to form protein-oligosaccharide on the protein. Chondroitin sulfate is widely distributed in the extracellular matrix and cell surface of animal tissues, the sugar chain consists of alternating glucose glyoxylic acid and N-acetyl galactose (also known as N-acetyl amino galactose), which is connected to the serine residues of the core protein through a sugar-like link region.
Chondroitin sulfate is present in all living organisms, from nematodes to humans, and plays many important physiological functions. Although the main chain structure of polysaccharides is not complex, it is highly heterogeneous in terms of the degree of sulfated, sulfuric acid and the distribution of two kinds of difference to the chain of the isomeric sugars. The fine structure of chondroitin sulfate determines the specificity of function and interaction with various protein molecules.