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Background: P450 BM3 is a high activity enzyme with biotechnological potential. Results: Mutations perturbing P450 BM3's conformational state and active site facilitate human P450-like oxidation of the drug omeprazole. Conclusion: Conformational destabilization enables P450 BM3 to explore novel conformations and accept diverse substrates. Significance: "Gatekeeper" mutations that decrease the energetic barrier for transition to the substrate-bound state can reconfigure P450 BM3 specificity and reactivity.

Pyrethroid resistance is widespread in the malaria vector Anopheles gambiae leading to concerns about the future efficacy of bednets with pyrethroids as the sole active ingredient. The incorporation of pyriproxyfen (PPF), a juvenile hormone analogue, into pyrethroid treated bednets is being trialed in Africa. Pyrethroid resistance is commonly associated with elevated levels of P450 expression including CYPs 6M2, 6P2, 6P3, 6P4, 6P5, 6Z2 and 9J5. Having expressed these P450s in E. coli we find all are capable of metabolizing PPF. Inhibition of these P450s by permethrin, deltamethrin and PPF was also examined. Deltamethrin and permethrin were moderate inhibitors (IC 1-10 μM) of diethoxyfluorescein (DEF) activity for all P450s apart from CYP6Z2 (IC > 10 μM), while PPF displayed weaker inhibition of all P450s (IC > 10 μM) except CYP's 6Z2 and 6P2 (IC 1-10 μM). We found evidence of low levels of cross resistance between PPF and other insecticide classes by comparing the efficacy of PPF in inhibiting metamorphosis and inducing female sterility in an insecticide susceptible strain of An. gambiae and a multiple resistant strain from Cote d'Ivoire.

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