Thrombin inhibitors, their production method, this extract polypeptide and its production method

摘要

Purified polypeptide with inhibiting thrombin activity, isolated from the tissue or secretion of leeches of the order Rhynchobdellida, selected from the polypeptide with relative molecular weight 9000 +/- 1000, which has following N-terminal sequence of amino acids Glu Asp Asp Asn Pro Gly Pro Pro Arg Ala Cys Pro Gly Glu or polypeptide with molecular weight 14000 +/- 1000, which has following N-terminal sequence of amino acids Ser Glu Leu Gly Gln Ser Cys Ser Lys Glu Asn Pro Cys Pro Ser Asn Met Lys Cys Asn Arg Glu Thr Phe Lys. This polypeptide production method, in which the tissue or secretion of leeches of the order Rhynchobdellida is homogenised, from the homogenate the fraction containing its water-soluble components and this fraction is purified by thrombin-specified affinity chromatography, followed by at least one level of jelly filtration and at least one next HPLC stage with reserve phases. The invention relates to novel polypeptides with antithrombin activity obtainable from extracts of tissues or secretions of leeches of the order Rhynchobdellida, particularly of the species Theromyzon tessulatum. The polypeptides have molecular weights of about 14 kD, 9 kD and 3 kD and can be used in pharmaceutical compositions for the treatment of thrombosis related disorders and events.