Degradation of an alkaloid pheromone from the pale-brown chafer, Phyllopertha diversa (Coleoptera : Scarabaeidae), by an insect olfactory cytochrome P450
H. Wojtasek et Ws. Leal, Degradation of an alkaloid pheromone from the pale-brown chafer, Phyllopertha diversa (Coleoptera : Scarabaeidae), by an insect olfactory cytochrome P450, FEBS LETTER, 458(3), 1999, pp. 333-336
The pale-brown chafer, Phyllopertha diversa, utilizes an unusual alkaloid,
1,3-dimethyl-2,4-(1H,3H)-quinazolinedione as its sex pheromone, This compou
nd is rapidly degraded in vitro by the antennal protein extracts from this
scarab beetle. Demethylation at the N-1 position and hydroxylation of the a
romatic ring have been identified as the major catabolic pathways, The enzy
me responsible for the pheromone degradation is membrane-bound, requires NA
D(P)H for activity and is sensitive to cytochrome P450 inhibitors, such as
proadifen and metyrapone. The ability to metabolize this unusual pheromone
was not detected in 12 species tested, indicating that the P450 system, spe
cific to male P, diversa antennae, has evolved as a mechanism for olfactory
signal inactivation. (C) 1999 Federation of European Biochemical Societies
.