title: Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.
abstract: Antennae-specific odorant-degrading enzymes (ODEs) are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs). Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW), Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.
authors.affiliation: Honorary Maeda-Duffey Laboratory, University of California Davis, Davis, California, United States of America.
authors.forename: Young-Moo
authors.initials: YM
authors.lastname: Choo
authors.forename: Julien
authors.initials: J
authors.lastname: Pelletier
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Atungulu
authors.forename: Walter S
authors.initials: WS
authors.lastname: Leal
mesh_terms: D000433:1-Propanol / Q000378:metabolism; D042931:Aldehyde Oxidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D057506:Arthropod Antennae / Q000187:drug effects / Q000201:enzymology*; D012831:Bombyx / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D020869:Gene Expression Profiling; D006358:Hot Temperature; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009036:Moths / Q000201:enzymology* / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D055503:Protein Multimerization / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D016415:Sequence Alignment; D012903:Smell / Q000187:drug effects; D013379:Substrate Specificity / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D000433:1-Propanol; D042931:Aldehyde Oxidase