Zymogen Activators

An isolated zymogen activating peptide (ZAP), wherein the ZAP consists of the amino acid sequence X1-X2-X3-X4-Bn (SEQ ID NO:2), wherein X1 is a large hydrophobic amino acid, X2 is a large hydrophobic amino acid or an aromatic amino acid, X3 is G, D, E, N, Q, D-Gly, D-Asp, D-Glu, D-Asn, or D-Gln, X4 is G or A, B is any amino acid, and n is a number between 0-46.

A method of identifying a ZAP capable of specifically binding a polypeptide comprising a serine protease domain or serine protease-like domain and activating the polypeptide comprising the serine protease zymogen domain or serine protease-like zymogen domain, said method comprising (a) contacting a first sample comprising a polypeptide or fragment thereof comprising a serine protease zymogen domain or serine protease-like zymogen domain in a pro-form and a candidate ZAP, (b) contacting a second sample comprising a polypeptide or fragment thereof comprising a serine protease zymogen domain or serine protease-like zymogen domain in a mature-form and the candidate ZAP, (c) determining the amount of binding of the candidate ZAP in (a) and (b), wherein greater binding of the candidate ZAP in (a) compared to (b) indicates that the candidate ZAP is capable of specifically binding the polypeptide comprising the serine protease domain or serine protease-like domain and activating the polypeptide comprising the serine protease zymogen domain or serine protease-like zymogen domain.