Method for the expression of heterologous proteins produced in fused form in E. coli, use thereof, expression vectors and recombinant strains

The present invention relates to the field of biotechnology and in particular the use of recombinant DNA technology for the production of heterologous proteins. The technical object thereof is to develop a highly efficient method for the expression of heterologous genes in fused form in E. coli, which code for proteins which can easily be purified owing to the fact that they are synthesized in insoluble form in the cellular cytoplasm. To achieve this, an expression vector is used which contains a stabiliser sequence which codes only for the first 58 amino acids belonging to the N-terminal end of the human protein interleukine-2, which is under the tryptophan promoter of the actual E. coli. This vector further contains the gene for resistance to ampicillin as a selection marker and the terminator of transcript ion of bacteriophage T4. In particular the genes which code for the antigenic proteins of the human immunodeficiency virus (HIV 1 and 2) were cloned therein, high levels of expression of said proteins being obtained from transformed strains of the bacteria Escherichia coli. The method which is the subject of the present invention can be employed for the expression at high levels of recombinant heterologous proteins synthesized in fused and insoluble form in E. coli, which can be used in the pharmaceutical industry to obtain vaccine preparations or in the development of diagnostic systems, in the food industry, in agriculture, etc.