Extracellular matrix protein heparan sulfate-binding sites

Extracellular matrix protein heparan sulfate-binding sites are specialized structural domains within proteins of the extracellular matrix (ECM), such as fibronectin, laminin, and perlecan, that mediate interactions with heparan sulfate (HS) glycosaminoglycans (Xu and Esko, 2014). These sites typically consist of clusters of basic amino acids, notably lysine and arginine, which form electrostatic bonds with the negatively charged sulfate and carboxyl groups of HS (Cardin and Weintraub, 1989). Biologically, these interactions are essential for the assembly of the ECM and the sequestration of various signaling molecules, including fibroblast growth factors (FGF) and vascular endothelial growth factors (VEGF), thereby regulating their stability and bioavailability (Whitelock and Iozzo, 2005). In disease states like cancer, these sites facilitate tumor progression by acting as a reservoir for pro-angiogenic factors that are released upon ECM degradation by enzymes like heparanase (Kudoh et al., 2010). Furthermore, many viruses and bacteria utilize these HS-binding sites on host ECM proteins or cell surfaces as initial attachment points for infection (Spillmann, 2001). Therapeutic targeting of these sites involves the use of heparin mimetics, such as muparfostat, which competitively inhibit HS-protein interactions to disrupt pathological signaling and inhibit angiogenesis or pathogen entry (Dredge et al., 2010).

Other names

Heparan sulfate-binding domainsHS-binding motifsGAG-binding sitesCardin-Weintraub motifs

Competitive inhibition of heparan sulfate-protein interactions and displacement of sequestered growth factors