Hirudine mutant, production thereof, anticoagulant, secretory vector, microorganism transformed by said vector, and production of product from said microorganism

摘要

A hirudine mutant HVIC3 prepared by replacing an amino acid sequence starting with the 53rd amino acid residue of hirudine HV1 by an amino acid sequence starting with the 53rd amino acid residue of hirudine HV3, said mutant not only having a high antithrombin effect, but also serving to inhibit the elongation of bleeding time. Escherichia coli transformed by a foreign protein secretory vector comprising a DNA sequence containing an origin (ori) of pUC plasmid, a DNA sequence of tac promoter or trp promoter, a DNA sequence coding for signal peptide and a DNA sequence coding for foreign protein, which secretes and produces foreign proteins in large amounts outside the cells.