Heparin-binding proteins (HBPs)

Heparin-binding proteins (HBPs) are a diverse group of proteins that possess a high affinity for heparin and other glycosaminoglycans. This group encompasses a wide range of functional classes, including coagulation factors like antithrombin III and thrombin, as well as growth factors such as fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). The binding typically occurs through clusters of basic amino acids on the protein surface that interact with the highly anionic sulfate groups of heparin (Capila & Linhardt, 2002). In the context of anticoagulation, heparin acts by binding to antithrombin III, inducing a conformational change that dramatically increases its ability to inhibit thrombin and Factor Xa (NIH, 2023). Beyond hematology, HBPs play critical roles in cell signaling, where heparin-like molecules act as co-receptors or protect growth factors from degradation (Ori et al., 2011). Therapeutic targeting of these proteins is central to managing thromboembolic disorders, though the broad reactivity of heparin can lead to off-target effects. One significant complication is heparin-induced thrombocytopenia, caused by antibodies against the heparin-platelet factor 4 complex (StatPearls, 2023). Understanding the heparin-binding proteome is essential for developing more selective heparin mimetics with reduced side effects.

Other names

Heparin-binding proteomeHeparin-binding growth factorsHeparin-binding cytokinesMultiple heparin-binding proteins

Drugs like heparin bind to these proteins to induce conformational changes (e.g., activating antithrombin III) or to sequester/modulate the activity of growth factors and cytokines.