Ac-TVASSSTA is an Octapeptide mimic of the N-terminal residues of the reactive center loop of PAI-1 (cf. P14-P7 residues). The Octapeptide inactivates PAI-1 by substituting for strand 4 in beta-sheet A in a manner that competes with formation of the latent species. Insertion of the peptide into beta-sheet A effectively forms a stable complex that converts PAI-1 into a substrate for tissue-type plasminogen activator (tPA) and other target proteinases. The resulting species of PAI-1 is thermodynamically stable and is useful for investigating the role of reactive center loop insertion. Supplied as a lyophilized powder. Add deionized water to original volume, aliquot and freeze unused portion.