Plasminogen activator inhibitor 1 (PAI-1) (PAI-1)

Plasminogen activator inhibitor 1 (PAI-1), also known as SERPINE1, is a key regulatory protein in the fibrinolytic system and a member of the serpin superfamily. Its primary biological function is the inhibition of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), which are essential for the conversion of plasminogen to plasmin. By controlling this process, PAI-1 regulates the degradation of fibrin clots and the remodeling of the extracellular matrix. Pathologically, elevated PAI-1 levels are strongly linked to the development of tissue fibrosis, chronic inflammation (such as in Inflammatory Bowel Disease), and tumor progression. The "A3SMO-mediated protein-protein interaction surface" refers to a specific targetable site on the PAI-1 molecule identified or targeted using the A3SMO platform, a technology for designing amino acid-based small molecule inhibitors. Experimental drugs like LDN-071 target this surface to block PAI-1's inhibitory activity, offering a therapeutic approach to treat fibrotic and inflammatory diseases by restoring normal plasminogen activation.

Other names

SERPINE1Serpin E1Endothelial plasminogen activator inhibitorPlan-1

Small molecule inhibition of the protein-protein interaction surface of PAI-1, preventing its binding to tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA), thereby promoting plasminogen activation and fibrinolysis.