New fluorogenic substrates for alpha-thrombin, factor Xa, kallikreins, and urokinase

J Biochem. 1977 Nov;82(5):1495-8. doi: 10.1093/oxfordjournals.jbchem.a131840.


Twenty peptide-4-methylcoumarin amides (MCA) were newly synthesized and tested as possible substrates for alpha-thrombin, factor Xa, kallikreins, urokinase, and plasmin. These fluorogenic peptides contained arginine-MCA as the carboxyl-terminus. Release of 7-amino-4-methylcoumarin was determined fluorometrically. Of these peptides, the following were found to be specific substrates for individual enzymes: Boc-Val-Pro-Arg-MCA for alpha-thrombin, Boc-Ile-Glu-Gly-Arg-MCA, and Boc-Ser-Gly-Arg-MCA for factor Xa, Z-Phe-Arg-MCA for plasma kallikrein, Pro-Phe-Arg-MCA for pancreatic and urinary kallikreins, and glutaryl-Gly-Arg-MCA for urokinase. Moreover, these peptide-MCA substrates were resistant to plasmin.

MeSH terms

  • Animals
  • Coumarins
  • Endopeptidases / metabolism*
  • Factor X / metabolism*
  • Kallikreins / metabolism*
  • Pancreas / enzymology
  • Structure-Activity Relationship
  • Substrate Specificity
  • Thrombin / metabolism*
  • Urokinase-Type Plasminogen Activator / metabolism*


  • Coumarins
  • Factor X
  • Endopeptidases
  • Kallikreins
  • Thrombin
  • Urokinase-Type Plasminogen Activator