VDAC2 protein identified to be over expressed in over-stunned chicken is a potential biomarker in differentiating stunned chicken and the voltage applied during the process. The VDAC2 gene was amplified by proofread DNA polymerase, then purified and inserted into pENTR-TEV-D-TOPO entry vector and transformed into One Shot TOP 10 Chemically Competent E. coli. The entry clone then was sub cloned into pDEST17 expression vector using LR recombinase in E. coli DH5a as the host. The vector construct was transformed into E. coli BL21-AI for protein expression. Recombinant VDAC2 protein was purified by affinity chromatography using Ni-NTA spin-column. Western blot using polyclonal anti-N terminal human VDAC2 and anti-His tag, followed by secondary antibody AP goat anti-rabbit revealed a 34 kDa protein, confirming the expression of recombinant VDAC2. Post-induction temperature, concentration of L-arabinose and post-induction time were selected for optimization studies under Response Surface Methodology (RSM). The optimum predicted cultivation conditions for the maximum expression of recombinant VDAC2 was found to be at 29oC post-induction temperature, 6.8 hour post-induction time and 0.5% (w/v) L-arabinose with a predicted expression of recombinant VDAC2 intensity of 0.496. The experimental expression of recombinant VDAC2 intensity obtained was 0.496, which was very close to the predicted value. The expression of recombinant VDAC2 improved by almost 6-fold after the optimization process. Therefore, RSM is a suitable method for optimizing recombinant VDAC2 expression in E. coli to provide a better understanding of its characteristics and propertiesto become abiomarker in detecting over-stunned chicken.
Chicken, electrical stimulation, E. coli, recombinase reaction, optimization
© The Author(s) 2014. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.