To investigate the role of different regions of hirudin in the interaction with the proteinase thrombin, segments of hirudin containing 15-51 residues were synthesized. The C-terminal segment 40-65 inhibited the fibrinogen clotting activity of thrombin but not amidolysis of tosyl-Gly-Pro-Arg-p-nitroanilide. Central peptide 15-42 was insoluble at pH 7, but peptide 15-65 inhibited fibrinogen clotting and amidolysis to an equal extent. The N-terminal loop peptide 1-15 had no inhibitory activity and did not affect the potency of peptide 15-65. These data suggest that the central region inhibits catalysis. © 1990.
Binnie, C. G., Erickson, B. W., & Hermans, J. (1990). Inhibition of thrombin by synthetic hirudin peptides. FEBS Letters, 270(1–2), 85–89. https://doi.org/10.1016/0014-5793(90)81240-O