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AIM:To demonstrate the effect of lactose as an induceron expression of the recombinant proteins encoded byHelicobacter pylori ureB and hpaA,and Escherichia coliLTB and LTKA63 genes and to determine the optimalexpression parameters.METHODS:By using SDS-PAGE and BIO-RAD gel imageanalysis system,the outputs of the target recombinantproteins expressed by pET32a-ureB-E.coliBL21,pET32a-hpaA-E.coliBL21,pET32a-L TKA63-E.coliBL21 and pET32a-LTB-E.coliBL21 were measured when using lactose as inducerat different dosages,original bacterial concentrations,various inducing temperatures and times.The results ofthe target protein expression induced by lactose werecompared to those by isopropyl-β-D-thiogalactoside(IPTG).The proteins were expressed in E.coli.RESULTS:Lactose showed higher efficiency of inducingthe expression of rHpaA,rUreB,rLTB and rLTKA63 thanIPTG.The expression outputs of the target recombinantproteins induced at 37℃ were remarkably higher than thoseat 28℃.Other optimal expression parameters for the originalbacterial concentrations,dosages of lactose and inducingtime were 0.8,50g/L and 4h for rHpaA;0.8,100g/L and4h for rLTKA63;1.2,100g/L and 5 h for both rUreB andrLTB,respectively.CONCLUSION:Lactose,a sugar with non-toxicity and lowcost,is able to induce the recombinant genes to expressthe target proteins with higher efficiency than IPTG.Theresults in this study establish a beneficial foundation forindustrial production of Hpylorigenetic engineering vaccine.
AIM: To demonstrate the effect of lactose as an induceron expression of the recombinant proteins encoded byHelicobacter pylori ureB and hpaA, and Escherichia coli LTB and LTKA63 genes and determine the optimalexpression parameters. METHODS: By using SDS-PAGE and BIO-RAD gel image analysis system , the outputs of the target recombinant proteins expressed by pET32a-ureB-E. coli BL21, pET32a-hpaA-E. coli BL21, pET32a-L TKA63-E. coli BL21 and pET32a-LTB- E. coli BL21 were measured when using lactose as inducerat different dosages , Original bacterial concentrations, various inducing temperatures and times. The results of the target protein expression induced by lactose werecompared to those by isopropyl-β-D-thiogalactoside (IPTG). The proteins were expressed in E. coli .RESULTS: Lactose showed higher efficiency of inducing the expression of rHpaA, rUreB, rLTB and rLTKA63 than IPTG.The expression outputs of the target recombinant proteins induced at 37 ° C were remarkably higher than thoseat 28 ° C.Other optimal expression parameters for the originalbacterial concentrations, dosages of lactose and inducing time were 0.8, 50 g / L and 4 h for rHpaA; 0.8, 100 g / L and 4 h for rLTKA63; 1.2, 100 g / L and 5 h for both rUreB and rLTB, respectively.CONCLUSION: Lactose, a sugar with non-toxicity and lowcost, is able to induce the recombinant genes to expressthe target proteins with higher efficiency than IPTG. The results in this study establish a beneficial foundation forindustrial production of Hpylori genetic engineering vaccine.