L. Svendsen, B. Blombäck, M. Blombäck
Jun 1, 1972
Citations
1
Influential Citations
270
Citations
Quality indicators
Journal
Folia haematologica
Abstract
Abstract New, synthetic substrates for trypsin-like enzymes are described. These substrates consist in general of arginine p-nitroanilides in which the NH2-group of arginine is acylated with hydrophobic amino acids or peptides. The susceptibility of the peptide substrates is enhanced by benzoylation of the free NH2-terminal group. One of the most reactive substrates is Nα-benzoyl-phenylalanyl-valyl-arginine p -nitroanilide (Bz-Phe-Val-Arg-pNA). Some kinetic parameters for the substrates with trypsin, thrombin and Reptilase have been studied. Trypsin has a much higher affinity for Bz-Phe-Val-Arg-pNA than for benzoyl-DL-arginine p-nitroanilide (BAPNA). Bz-Phe-Val-Arg-pNA also has a high susceptibility toward thrombin and Reptilase. The narrow substrate specificity of thrombin as compared with trypsin is reflected by the fact that Bz-L-Phe-L-Val-L-Arg-pNA is rapidly hydrolyzed by thrombin while the rate of hydrolysis of Bz-D-Phe-L-Val-L-Arg-pNA is very slow. On the other hand the action of trypsin on the D-isomer is only slightly reduced. The synthetic peptide substrates are useful for determination of enzymes of the trypsin type, and they can also be used in biological fluids. Small amounts of trypsin, thrombin and Reptilase can be determined.