Optimizing of Brucella OprF Recombinant ProteinExpression as a Soluble Protein in Escherichia Coli

Introduction: To use Brucella oprF protein in various studies, it is necessary that the proteinto be pure. To increase the purity of proteins can be used from Escherichia coli to producerecombinant protein. Because E. coli bacteria do not give posttranslational modificationson the protein, the protein produced by the cells will accumulate as inclusion body. Theaim of this study was to optimize protein expression oprF by changing the concentrationof the inducer (Isopropyl β-D-1-thiogalactopyranoside) IPTG, induction time and changethe temperature in order to increase soluble protein expression in bacteria.Methods: Bl21 cells containing pET28a-oprF recombinant plasmid inoculated to equalvolume of Treffic broth medium in different bottles and incubated in 37ºC up to OD 600 to0.6. Then, four medium were induced by 0.1 mM IPTG and two of them induced by 1mMIPTG. Medium incubated in three different temperatures 18, 23, 37ºC. The expression ofrecombinant protein follows by SDS-PAGE analysis.Results: Inducing Bl21 cells containing recombinant plasmid with 0.1 mM IPTG andincubation at 18 ° C for 15 hours is the best condition for oprF protein expression asasoluble form.Conclusions: Solubility of oprF protein was increased by lowering the growthtemperatureand inducer concentration.

Keywords:

BrucellaOprFProtein Expression