Modified proteins

Claim 1

A process for the production of mutants of desulphatohirudin having the amino acid sequence wherein Y₁ represents Asp or the radical of a neutral genetically encoded amino acid, Y₂ and Y₃ independently from each other represent Glu, Asn or the radical of a lipophilic genetically encoded amino acid, Y₄ and Y₅ independently from each other represent Glu or the radical of a neutral genetically encoded amino acid, Y₆ represents Tyr or the radical of an acidic genetically encoded amino acid and Y₇ represents Gln or the dipeptidyl radical GlnPro, with the exception of compounds of the formula I in which Y₁ is Asp, Y₆ is Tyr, Y₇ is Gln, Y₂ and Y₃ are each Glu and one of the radicals Y₄ and Y₅ is Gln and the other is Glu, and salts thereof, which process comprises culturing a microbial host strain which has been transformed with a hybrid vector comprising an expression cassette consisting of a promoter operably linked to a first DNA sequence encoding a signal peptide linked in the proper reading frame to a second DNA sequence coding for the desulphatohirudin mutant, and a DNA sequence containing transcription termination signals, and isolating the desul­phatohirudin mutant, and, if desired, converting an obtained polypeptide having free carboxy and/or amino groups into a salt or converting a salt obtained into the free compound.