FIELD: biotechnology, biochemistry, medicine. SUBSTANCE: protein with molecular mass 18 000 ± 3 000 Da and value pI = 4.5-5.2 is isolated from saliva of bug Triatoma pallidipennis and this protein shows property of thrombin inhibitor. Using oligonucleotide probe synthesized on data of determination of N- terminal sequence of amino acid of isolated natural protein DNA fragments encoding a precursor of protein and its active form are prepared. Indicated DNA fragments are inserted in expression vector that is used for transformation of the strain E. coli. By culturing the prepared recombinant strain the expression of recombinant analogue of thrombin inhibitor from bug saliva is performed. After purification by chromatography methods both forms (natural and recombinant) of polypeptide and their mixture can be used as a medicinal agent in treatment of patients with thrombosis, nonpermanent stenocardia, arteriosclerosis and so on being both directly and as component of pharmaceutical composition. EFFECT: improved method of preparing, valuable medicinal properties. 3 dwg, 2 tbl, 12 ex
