Glycosaminoglycan (Heparin and Heparan sulfate) (GAG)

Glycosaminoglycans (GAGs), specifically heparin and heparan sulfate, are complex, highly sulfated linear polysaccharides found on cell surfaces and within the extracellular matrix. They play a critical role in biological processes by interacting with a vast array of proteins, including growth factors, antithrombin, cytokines, and viral attachment proteins. In healthy physiology, they regulate blood coagulation and cell signaling; however, in disease states, they are exploited by viruses for cellular entry and by cancer cells to facilitate angiogenesis and metastasis. Heparan sulfate serves as a co-receptor for various ligands, while heparin is a potent natural anticoagulant stored in mast cells. Therapeutic targeting of these molecules involves neutralizing their negative charge, using mimetics to block protein interactions, or inhibiting the enzymes like heparanase that modify them. Understanding the GAG interactome is essential for developing treatments for thrombosis, inflammatory disorders, and infectious diseases.

Other names

MucopolysaccharideHeparin sulfateHeparan sulfate proteoglycanHSHSPGHeparin sodium

Drugs targeting these molecules typically act through electrostatic neutralization (e.g., protamine binding to acidic heparin), competitive inhibition of ligand-GAG interactions (e.g., HS mimetics blocking growth factor binding), or enzymatic degradation of the polysaccharide chains to disrupt the extracellular matrix and signaling scaffolds.