Abstract
Insecticide-detoxifying carboxylesterase (CE) gene CpCE-1 was cloned from Cydia pomonella. Molecular dynamics (MD) simulation and computational alanine scanning (CAS) indicate that Asn 232 in CpCE-1 constitutes an approximate binding hot-spot with a binding free energy difference (ΔΔG bind) value of 3.66 kcal/mol. The catalytic efficiency (kcat/km) of N232A declined dramatically, and the half inhibitory concentrations (IC 50) value increased by more than 230-fold. Metabolism assay in vitro reveals that the acephate could be metabolized by wild CpCE-1, whereas N232A mutation is unable to metabolize the acephate, which suggests that the hot-spot Asn 232 is a crucial residue for acephate metabolism. Mutation detection suggests that low frequency of Asn 232 replacement occurred in Europe field strains. Our MD, CAS, site-directed mutagenesis, and metabolism studies introduce a new amino acid residue Asn 232 involved in the metabolism of the acephate with CpCE-1, and this method is reliable in insecticide resistance mechanism research and prediction of key amino acids in a protein which is associated with specific physiological and biochemical functions.
Original language | English (US) |
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Pages (from-to) | 1356-1370 |
Number of pages | 15 |
Journal | Journal of Chemical Information and Modeling |
Volume | 54 |
Issue number | 5 |
DOIs | |
State | Published - Apr 28 2014 |
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Computer Science Applications
- Library and Information Sciences