The role of esterases in insecticide resistance

摘要

Esterases are a large, heterogeneous group of enzymes metabolizing a variety of exogenous and endogenous substrates with ester linkages. Traditionally, esterases have been arbitrarily classified in the literature by their ability to metabolize artificial or endogenous substrates or by their electrophoretic characteristics under non-standardized conditions. The lack of a molecular approach to esterase classification has and will continue to be the single most important factor preventing progress in understanding probably the most diverse group of xenobiotic metabolizing enzymes in nature. The level of insect esterase activity is highly variable depending on the life stage, sex, tissue, hormones, strain, food, food quality, environmental conditions and numerous other factors. Esterases have been associated with insecticide resistance in over 50 species of insects, ticks and mites. The functional roles of esterases in pesticide resistance are xenobiotic metabolism and sequestration. Recent advances in the use of transition state analog chemistry to characterize insect esterase structure and function promises new, easier methods for esterase purification and for examining in vivo function. Esterases have also been used successfully in numerous cases as a marker for detecting insecticide resistance. Further studies are needed on the molecular biology of esterases and the evolution of esterase-mediated insecticide resistance that will have a practical importance to the management of resistance in the context of integrated pest management.