Investigation of the Relationship between Protein, Message and Inducer Concentrations in Recombinant E. coli Cells

  • Jorgensen, Lene (Department of Microbiology and Immunology, The University of Adelaide) ;
  • Connor J. Thomas (Department of Microbiology and Immunology, The University of Adelaide) ;
  • Brian K. Oneill (Cooperative Research Center for Tissue Growth and Repair, Department of Chemical Engineering, The University of Adelaide) ;
  • Anton P.J. Middelbeg (Cooperative Research Center for Tissue Growth and Repair, Department of Chemical Engineering, The University of Adelaide)
  • Published : 1997.02.01

Abstract

Chloramphenicol acetyl transferase (CAT) protein and mRNA levels in E. coli were determined following induction of a tac::cat construct by isopropyl-${\beta}$-thiogalactopyranoside (IPTG). High cat mRNA levels did not directly reflect CAT protein levels, in either shakeflask experiments or fermentations. Furthermore, concentrations of IPTG resulting in the highest levels of expression of cat mRNA, were different to those resulting in highest levels of CAT protein. The data suggest that high transcriptional activities lead to limitations at the translational level.

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