[Expression of the gag-precursor of the human T-cell leukemia virus type I in Escherichia coli: study of the stability and antigenic properties of virus-specific hybrid proteins].

A set of recombinant plasmids containing sequences of HTLV-I viral gag-gene has been constructed on the basis of pUR290-pUR292 vector plasmids. The resulting hybrid proteins containing different fragments of GAG-precursor in the C-end of beta-galactosidase differed to a large extent in stability in Escherichia coli cells. The presence of an N-end fragment of GAG-precursor in the recombinants decreases drastically their resistance to bacterial proteases. Elimination of the fragment resulted in obtaining the recombinant plasmid pGdN coding for high rate synthesis (up to 30% of total cellular protein) of gag-specific hybrid polypeptide in Escherichia coli HB101 cells. This 145 kDa protein efficiently interacts with HTLV-I positive sera. It can be used in diagnostic test-systems for indicating HTLV-I infected persons.