Human HGF Activator Antibody

Hepatocyte Growth Factor Activator (HGFA) is a serine endopeptidase that cleaves at the peptide bond between Arg494 and Val495 of single-chain human HGF precursor, generating the active heterodimer (1). HGFA is produced and secreted by the liver and normally circulates in the blood as an inactive zymogen (2, 3). The zymogen has a weak affinity for heparin but acquires a strong affinity for heparin upon activation that is linked to blood coagulation. This property may ensure the local action of this enzyme at the site of tissue injury (3). Human HGFA precursor (655 amino acid residues) contains several predicted domains including a signal peptide (residues 1‑30), a propeptide (residues 31‑372), and a mature and active form (residues 373‑655) that is further processed into a short chain (residues 373‑407) and a long chain (residues 408‑655). The short chain and the long chain (catalytic domain) may form a disulfide bond linked dimer. HGFA can be activated by thrombin (R&D Systems, Catalog # 1473-SE) or thermolysin (R&D Systems, Catalog # 3097-ZN) (4). The active protease can be inhibited by HGFA inhibitors (HAIs). Two HAIs, HAI-1 and HAI-2, are known in mouse and human. HAI-1 is not only an inhibitor, but also a specific acceptor of active HGFA, acting as a reservoir of this enzyme on the cell surface (5).