Effect of Vitreoscilla hemoglobin on recombinant protein expression and energy and redox state of CHO cells

Vitreoscilla hemoglobin (VHb) expression confers considerable improvements to microbial cell factories. However, the effect of VHb on animal cells has been scarcely studied. To gain insight about the impact of VHb on aerobic energy metabolism and recombinant protein expression, CHO-K1 cells stably expressing the green fluorescent protein (GFP) were obtained and transfected for VHb expression. GFP expression slightly increased, whereas cell viability and the mitochondrial membrane potential were not affected by VHb expression. In contrast, the NAD+/NADH ratio and ATP cell content tended to decrease, while the NADP+/NADPH ratio increased as a consequence of VHb presence. These results suggest that VHb can improve recombinant protein expression in CHO cells by altering the energy metabolism. This can be useful for the design of robust cell factories for industrial applications.

Keywords: Bismuth, Silver, Nanoparticles, Minimum Inhibitory Concentration, Synergistic Effect.