Collect. Czech. Chem. Commun. 1990, 55, 1112-1118

New fluorogenic substrates for the determination of post-proline endopeptidase activity

Chryssa Tzougrakia, George Kokotosa, Hana P. Maškováb, Eva Anzenbacherováb and Tomislav Barthb

a Department of Chemistry, University of Athens, Athens 106 80, Greece
b Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia


A new fluorogenic substrate for determination of the activity of post-proline endopeptidase (EC, Z-Cys(Bzl)-Pro-NH-Meq has been synthesized. Affinity of this substrate to the enzyme was significantly higher than that of the hitherto employed substrates. The Michaelis constant of the post-proline endopeptidase for Z-Cys(Bzl)-Pro-NH-Meq was at the optimum pH (7.0) 1.05 10-6 mol l-1. The concentration of dimethylsulfoxide used for the solubilization of Z-Cys(Bzl)-Pro-NH-Meq (<0.4%) was outside the limits of adverse influence of the organic solvent on the enzyme activity. The fluorogenic substrate Z-Gly-Pro-NH-Meq was also synthesized for comparison (Km = 10.35 10-6 mol l-1 at pH 7.0).