In this paper,we compared the sensitivities of AFEST(a thermophilic esterase from the archaea Archaeoglobus fulgidus) and acetylcholinesterase(AChE) towards five organophosphorus compounds(OPs) by means of molecular docking,and found that only the docking energy between AFEST and dichlorvos is lower than that between AChE and dichlorvos.Via the docking model of AFEST and dichlorvos,Arg43 was found to play an important role in the interaction between AFEST and dichlorvos by means of stabilizing the complex.Then mutant R43S was constructed,the IC 50(the concentration required to reduce virus-induced cytopathicity by 50% is estimated as 50% inhibitory concentration) of which to dichlorvos was lower than that of the wild type AFEST by a factor of 1.56,indicating the enhanced sensitivity of mutant R43S to dichlorvos.Combining of theory with experiment,we have obtained important structure-function information of AFEST,which will be helpful to the further studies of esterase.
