Preparation Note: Proteoglycans are extracted from articular cartilage with guanidine hydrochloride. Further purification includes gel filtration and ion exchange chromatography. The product is dialyzed against water and sterile-filtered prior to lyophilization.
Storage: −20°C
Biochem/physiol Actions: Major structural proteoglycan of cartilage extracellular matrix. Large proteoglycan with a molecular weight greater than 2,500 kDa. Approximately 100-150 glycosaminoglycan (GAG) chains are attached to the core protein (210-250 kDa). The majority of the GAG chains are chondroitin/dermatan sulfate with the remainder being keratan sulfate. This structural molecule produces a rigid, reversibly deformable gel that resists compression. It combines with hyaluronic acid to form very large macromolecular complexes. Addition of small amounts (0.1-2% w/w) of hyaluronic acid to an aggrecan solution (2mg/ml) results in the formation of a complex with an increased hydrodynamic volume and in a significant increase (30-40%) in the relative viscosity of the solution. Aggrecan is a critical component for cartilage structure and the function of joints. The synthesis and degradation of aggrecan are being investigated for their roles in cartilage deterioration during joint injury, disease, and aging. Contains three globular domains, G1, G2, and G3, that are involved in aggregation and hyaluronan binding, cell adhesion, and chondrocyte apoptosis.
Empirical Formula (Hill Notation): C8H11BO4