Abz-Val-Ala-Asp-Nva-Arg-Asp-Arg-Gln-EDDnp is a fluorescence-quenched peptide substrate for human proteinase 3 (kcat/Km = 1,570 mM-1s-1). Enzymatic peptide hydrolysis disrupts the Abz:EDDnp donor-acceptor pair allowing fluorescence measurement of Abz (ex = 320 nm; em = 420 nm).