| Title: | Structure of an antennally-expressed carboxylesterase suggests lepidopteran odorant degrading enzymes are broadly tuned |
| Author(s): | Corcoran JA; Hamiaux C; Faraone N; Lofstedt C; Carraher C; |
| Address: | "USDA - Agricultural Research Service, Biological Control of Insects Research Laboratory, Columbia, MO, USA. Department of Biology, Lund University, Lund, Sweden. The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand. Department of Chemistry, Acadia University, Wolfville, Nova Scotia, Canada" |
| DOI: | 10.1016/j.cris.2023.100062 |
| ISSN/ISBN: | 2666-5158 (Electronic) 2666-5158 (Linking) |
| Abstract: | "Insects rely on the detection of chemical cues present in the environment to guide their foraging and reproductive behaviour. As such, insects have evolved a sophisticated chemical processing system in their antennae comprised of several types of olfactory proteins. Of these proteins, odorant degrading enzymes are responsible for metabolising the chemical cues within the antennae, thereby maintaining olfactory system function. Members of the carboxyl/cholinesterase gene family are known to degrade odorant molecules with acetate-ester moieties that function as host recognition cues or sex pheromones, however, their specificity for these compounds remains unclear. Here, we evaluate expression levels of this gene family in the light-brown apple moth, Epiphyas postvittana, via RNAseq and identify putative odorant degrading enzymes. We then solve the apo-structure for EposCCE24 by X-ray crystallography to a resolution of 2.43 A and infer substrate specificity based on structural characteristics of the enzyme's binding pocket. The specificity of EposCCE24 was validated by testing its ability to degrade biologically relevant and non-relevant sex pheromone components and plant volatiles using GC-MS. We found that EposCCE24 is neither capable of discriminating between linear acetate-ester odorant molecules of varying chain length, nor between molecules with varying double bond positions. EposCCE24 efficiently degraded both plant volatiles and sex pheromone components containing acetate-ester functional groups, confirming its role as a broadly-tuned odorant degrading enzyme in the moth olfactory organ" |
| Keywords: | Carboxyl/cholinesterase Crystal structure Epiphyas postvittana Gc-ms Odorant degrading enzyme RNAseq; |
| Notes: | "PubMed-not-MEDLINECorcoran, Jacob A Hamiaux, Cyril Faraone, Nicoletta Lofstedt, Christer Carraher, Colm eng Netherlands 2023/07/03 Curr Res Insect Sci. 2023 Jun 5; 3:100062. doi: 10.1016/j.cris.2023.100062. eCollection 2023" |
