Characterization of inhibitors and substrates of Anopheles gambiae CYP6Z2
Résumé
Three CYP6Z genes are linked to a major pyrethroid resistance locus in the mosquito Anopheles gambiae. We have expressed CYP6Z2 in Escherichia coli and produced a structural model in order to examine its role in detoxification. E. coli membranes co-expressing CYP6Z2 and An. gambiae P450 reductase (AgCPR) catalysed the dealkylation of benzyloxyresorufin with kinetic parameters K-m = 0.13 mu M; K-cat = 1.5 min(-1). The IC50 values of a wide range of compounds were measured. Pyrethroids cypermethrin and permethrin produced low IC50 values, but were not metabolized. Plant flavanoids were the most potent inhibitors. Several compounds were shown to be substrates, suggesting that CYP6Z2 has broad substrate specificity and plays an important chemo-protective role during the herbivorous phase of the life-cycle.