New thrombininhibitory proteins from land leeches

Described are new thrombin-inhibiting proteins obtained from terrestrial leeches of the species Haemadipsa and with the amino-acid sequence Ile-Arg-Phe-Gly-Met-Gly-Lys-Val-Pro-Cys-Pro-Asp-Gly-Glu-Val-Gly-Tyr-Th r-Cys-Asp-Cys-Gly-Glu-Lys-Ile-Cys-Leu-Tyr-Gly-Gln-Ser-Cys-Asn-Asp-Gly- Gln-Cys-Ser-Gly-Asp-Pro-Lys-Pro-Ser-Ser-Glu-Phe-Glu-Glu-Phe-Glu-Ile-As p-Glu-Glu-Glu-Lys or an amino-acid sequence obtained by C-terminal shortening the above sequence by one to twelve amino acids. The proteins are suitable for use against illnesses. Also described are the nucleic acids coding for these proteins.