Description
Aggrecan is a large aggregating proteoglycan of articular cartilage. It is also found in aorta, discs and tendons. The aggrecan core protein consists of 2317 amino acids. Up to 130 glucosaminoglycan chains are attached to the core protein and the total molecular mass can reach 2.2 - 3.0 x 106 Daltons. Within the aggrecan molecule 3 globular domains G1, G2 and G3 can be distinguished. Domains G1 and G2 are connected by a rod-shaped polypeptide called interglobular domain (IGD), while the sequence between domains G2 and G3 contains attachment regions for keratan sulfate and chondroitin sulfate chains. Aggrecan interacts via the G1 domain with hyaluronan and link protein to form large aggregates