Synthesis of stereoisomeric Suc-Tyr-Leu-Val-pNA and their properties as substrate and inhibitor for human spleen fibrinolytic proteinase (SFP).

Stereoisomeric analogues of Suc-Tyr-Leu-Val-pNA were synthesized in the conventional manner and their properties as the substrate and/or the inhibitor against human spleen fibrinolytic proteinase (SFP) were tested. Suc-D-Tyr-L-Leu-L-Val-pNA (II) was hydrolyzed to release p-nitroaniline with Keat/Km value (3700), whereas Keat/Km value of Suc-L-Tyr-L-Leu-L-Val-pNA (I) was 22647. Suc-L-Tyr-D-Leu-D-Val-pNA (III) inhibited the hydrolytic activity of SFP towards both the peptide (I) and fibrin.