A Genomics Perspective on Mutant Aliesterases and Metabolic Resistance to Organophosphates

摘要

There are now five insect taxa for which the molecular mechanisms underlying metabolic resistance to organophosphates have been determined. Essentially only three mechanisms have been found, all involving closely related enzymes in the carboxyl/cholinesterase multigene family. None of them generate an enzyme that is kinetically efficient in degrading a broad range of organophosphates. Paradoxically however several kinetically more efficient enzymes have been found in other eukaryotes and prokaryotes and their homologs are very likely to occur in insects. These homologs may explain several cases of esterase mediated metabolic resistance whose biochemistries are distinct from the five cases so far resolved at a molecular level.