FIELD: biotechnologies.
SUBSTANCE: method consists in expression of a gene of a human plasminogen fragment from 453 to 543 amino acid within E.coli cells with subsequent extraction and treatment of a finished product from cell periplasm. Expression is carried out in cells E.coli BL21 (DE3), transformed by plasmid DNA pEK5 or pEK5H with physial maps represented in figure 2, containing a gene of target polypeptide fused with a gene of signal peptide OmpA, origin of replication pUC ori, a gene of resistance to kanamycin and a gene coding lac-repressor under control of T7-promotor. At the same time the recombinant plasmid DNA pEK5H additionally contains between genes OmpA and target polypeptide the sections coding amino acid sequences HHHHHH and DDDDK.
EFFECT: invention provides for secretion of target polypeptide into cell periplasm with high yield.
4 cl, 5 dwg, 6 ex
