Design of Specific Serine Protease Inhibitors Based on a Versatile Peptide Scaffold: Conversion of a Urokinase Inhibitor to a Plasma Kallikrein Inhibitor
All serine proteases hydrolyze peptide bonds by the same basic mechanism and have very similar active sites, in spite of the fact that individual proteases have different physiological functions. We here report a strategy for designing high-affinity and high-specificity serine protease inhibitors using a versatile peptide scaffold, a 10-mer peptide, mupain-1 (CPAYSRYLDC). Mupain-1 was previously reported as a specific inhibitor of murine urokinase-type plasminogen activator (Ki = 0.55 μM) without measurable affinity to plasma kallikrein (Ki > 1000 μM). On the basis of a structure-based rational design, we substituted five residues of mupain-1 and converted it to a potent plasmamore »