Plasmin dissolves the fibrin of blood clots and acts as a proteolytic factor in a variety of other processes including embryonic development, tissue remodeling, tumor invasion, and inflammation. In ovulation, weakens the walls of the Graafian follicle. It activates the urokinase-type plasminogen activator, collagenases and several complement zymogens, such as C1 and C5. Cleavage of fibronectin and laminin leads to cell detachment and apoptosis. Also cleaves fibrin, thrombospondin and von Willebrand factor. Its role in tissue remodeling and tumor invasion may be modulated by CSPG4. Binds to cells (By similarity). Preferential cleavage: Lys-|-Xaa > Arg-|-Xaa, higher selectivity than trypsin. Converts fibrin into soluble products. Converted into plasmin by plasminogen activators, both plasminogen and its activator being bound to fibrin. Activated with urokinase and high concentrations of streptokinase. Interacts with CSPG4 and AMOT. Interacts (via the Kringle domains) with HRG; the interaction tethers PLG to the cell surface and enhances its activation. Interacts (via Kringle 4 domain) with ADA; the interaction stimulates PLG activation when in complex with DPP4. Angiostatin: Interacts with ATP5F1A; the interaction inhibits most of the angiogenic effects of angiostatin. Locates to the cell surface where it is proteolytically cleaved to produce the active plasmin. Interaction with HRG tethers it to the cell surface (By similarity). Kringle domains mediate interaction with CSPG4. Plasmin is inactivated by alpha-2-antiplasmin immediately after dissociation from the clot. Belongs to the peptidase S1 family. Plasminogen subfamily.