Engineering thermostable and industrially useful cytochrome P450 enzymes

RES Thomson

School of Chemistry and Molecular Biosciences, University of Queensland

Cytochromes P450 show potential for use as biocatalysts in industrial processes because of their ability to catalyse a wide range of stereo- and regio-specific reactions that are difficult to achieve synthetically. However, there are currently many limitations to using these proteins including the relative lack of thermostability of the native forms. Previous studies have revealed that reconstructed ancestral P450s were significantly more thermostable than their extant descendants. To further investigate this phenomenon, twelve ancestor P450 proteins of increasing evolutionary age were inferred from extant enzymes of the CYP2 family, and characterised for their thermostability. The results show an overall trend of increased thermostability in proteins of an older evolutionary age. It is hypothesised that this stability is the result of an increased level of hydrophobic packing in the protein core. The next phase of this investigation is to assess the substrate range of these ancestral P450s to determine their catalytic capabilities and the trade-off between thermostability and promiscuity.