Glycosaminoglycan (heparin) (GAG (heparin))

Glycosaminoglycans (GAGs) are long, linear polysaccharides consisting of repeating disaccharide units, classified into types such as heparin, heparan sulfate, chondroitin sulfate, and others. Heparin is a highly sulfated GAG best known for its potent anticoagulant properties, achieved by potentiating antithrombin III and thereby inactivating thrombin and other clotting factors. Beyond blood coagulation, heparin and related GAGs are important modulators of cell signaling, extracellular matrix structure, and inflammation. Though heparin (as a drug) is therapeutically targeted, glycosaminoglycans as a class are molecular structures, not classical "targets" (like receptors or enzymes), and the term “glycosaminoglycans / heparin” is imprecise as a therapeutic target. GAGs can be exploited pharmacologically (e.g., exogenous heparin for anticoagulation), but are generally substrates and modulators, not drug targets themselves.

Other names

HeparinHeparan sulfate (closely related, but not identical)GAG (for the superclass)HSGAG (heparin/heparan sulfate glycosaminoglycan)Glycosaminoglycan

Potentiates antithrombin III (ATIII), leading to inhibition of thrombin (factor IIa) and factor Xa, providing anticoagulant effect. Binds numerous extracellular proteins (growth factors, cytokines) to modulate signaling