摘要
The plasmid pTLIL-2,which only directed a low-level expression of human interleukin 2(IL-2) cDNA in E.coli,was reconstructed:a series of deletions were made in 3'non-coding region of human IL-2 cDNA,and 7 recombinant plasmids with different deletions were selected,on the other hand, a Tac promoter sequence from pDR540 was inserted to upstream of IL-2 cDNA in pTLIL-2 so that pTLIL-2DT,which contains double Tac promoters,was constructed.And then,E.coli JM103 was transformed with the above 8 recombinant plasmids respectively.The expression efficiency of IL-2 cDNA in E.cbli transformed with different plasmids was evaluated by means of SDS-PAGE and measuring 3H-TdR incorporation of IL-2-dependent activated T lymphocytes in the presence of bacterial extracts.Three engineering strains with high efficiency of IL-2 expression were selected,and all of these strains could produce recombinant IL-2(rIL-2)4 times more than E.coil JM103/pTLIL-2.
The plasmid pTLIL-2,which only directed a low-level expression of human interleukin 2(IL-2) cDNA in E.coli,was reconstructed:a series of deletions were made in 3'non-coding region of human IL-2 cDNA,and 7 recombinant plasmids with different deletions were selected,on the other hand, a Tac promoter sequence from pDR540 was inserted to upstream of IL-2 cDNA in pTLIL-2 so that pTLIL-2DT,which contains double Tac promoters,was constructed.And then,E.coli JM103 was transformed with the above 8 recombinant plasmids respectively.The expression efficiency of IL-2 cDNA in E.cbli transformed with different plasmids was evaluated by means of SDS-PAGE and measuring 3H-TdR incorporation of IL-2-dependent activated T lymphocytes in the presence of bacterial extracts.Three engineering strains with high efficiency of IL-2 expression were selected,and all of these strains could produce recombinant IL-2(rIL-2)4 times more than E.coil JM103/pTLIL-2.
