Optimizations to achieve high-level expression of cytochrome P450 proteins using Escherichia coli expression systems

1)Evaluate expression conditions used previously to express P450 proteins.2)Summarize the effects of N-terminal modifications and silent mutations.3)Examine various N-terminal sequences in relation to expression localization.4)Updates on additional factors employed to increase protein expression yields. Recombinant expression of membrane-bound cytochrome P450s in bacterial expression systems provide a well-established system capable of producing large yields of catalytically active protein. As the biochemical knowledge regarding cytochrome P450s increases, so does the efficiency of protein expression through various modifications that do not disrupt the functional properties of the protein of interest. Changes such as N-terminal modifications, reduction of secondary mRNA structure, bacterial codon usage, selection of vector and host strain, as well as varying external growth conditions all appear to influence protein expression. Several optimizations are often required for sufficient expression of cytochrome P450s at the desired cellular localization. This review aims to comprehensively summarize and update the significant advances made in membrane protein P450 expression in bacterial expression systems.