Production of thrombin inhibitors

The invention pertains to the field of recombinant DNA technology and concerns a method for the preparation of the thrombin inhibitor desulphatohirudin with the aid of genetically engineered eukaryotic cells, said genetically engineered eukaryotic cells, hybrid vectors carrying a gene for desulphatohirudin and methods for the preparation of said eukaryotic cells and said hybrid vectors. A method for the production and secretion of proteins with hirudin activity in an eukaryotic host organism is provided. There are also provided hybrid vectors comprising a DNA sequence encoding a signal peptide upstream of and in reading frame with the structural gene for desulphatohirudin, and eukaryotic host organisms transformed with said hybrid vectors.