Expression of putative chitinase of Rhipicephalus sanguineus sensu lato in Rosetta (DE3) pLysS cells

Abstract

Recombinant protein expression from bacteria is less time consuming and more economical in comparison to other expression systems. However, bacterial expression systems fail to express certain proteins due to their inability to code for certain amino acids. Rosetta (DE3) pLysS cells possess the ability to express even such rare codons and are also capable of post translational modification to some extent. Expression of protein is also affected by factors like stage of induction with cell density, aerobic conditions and the toxic effect of metabolite produced post induction. In the current study, the ideal expression conditions needed to obtain optimum yield of a putative chitinase from Rhipicephalus sanguineus sensu lato using recombinant Rosetta (DE3)pLysS cells was evaluated. The expressed proteins were visualised in SDS-PAGE and confirmed by western blotting. Double selection of colonies expressing the recombinant protein was carried in the study. The study showed that induction at an OD600 range of 0.6-0.8 and aerobic conditions with the induction volume being one-fifth the flask volume favoured the expression of recombinant protein. Post-induction incubation periods of 1- 16hr did not influence protein production among the induced cultures.