The PAI-1 Activation Peptide is an octapeptide sequence (TVASSSTA) which mimics the N-terminal residues of the reactive center loop of PAI-1 (cf. P14-P7 residues). This substitution of strand 4 in beta-pleated sheet A competes with the formation of the latent species. This insertion then converts PAI-1 into a substrate for tissue-type plasminogen activator (tPA) and other target proteases. The result is a thermodynamically stable PAI-1 species that is useful for investigating the role of reactive center loop insertion. Supplied as a lyophilized powder.      References   1. Kvassman J.O. et al. (1998) Biochemistry 37:15491-15502.