Synthesis of plasmin substrates and relationship between their structure and plasmin activity

Abstract
The plasmin substrates, D‐Ile‐Phe‐Lys‐pNA (I), 3‐MV‐Phe‐Lys‐pNA (II), Ile‐Phe‐Lys‐pNA (III), D‐Pro‐Phe‐Lys‐pNA (IV), CP‐Phe‐Lys‐pNA (V) and Pro‐Phe‐Lys‐pNA (VI), were synthesized by the conventional solution method and the kinetic parameters of their amidolysis by plasmin were determined. It was found that the free amino group of the D‐amino acid in substrates (I) and (IV) made a contribution to an increment in affinity between the substrate and plasmin.