Recombinant Human Urokinase-Type Plasminogen Activator is a serine protease, which specifically cleaves the zymogen plasminogen to form the active enzyme plasmin. Urokinase-Type Plasminogen Activator is a potent marker of invasion and metastasis in many human cancers associated with breast, colon, stomach, bladder, brain, ovary and endometrium. Human Urokinase-Type Plasminogen Activator is initially synthesized as 431 amino acid precursor with a N-terminal signal peptide residues. The single chain molecule is processed into a disulfide-linked two-chain molecule. There exists two forms A chain, the long A chain contains an EGF-like domain that is responsible for binding of the uPA receptor. The B chain corresponds to the catalytic domain.