Alteration of the Binding Characteristics of a Recombinant scFv Anti-parathion Antibody - 2. Computer Modelling of Hapten Docking and Correlation with ELISA Binding

Recombinant antibody technology and the ability to manipulate antibody binding characteristics offers much potential to agri-food analysis, and in particular to the generation of antibodies against pesticides. As part of the development of a mutagenesis strategy aimed at changing antibody specificity, the sequence of an scFv recombinant antibody specific to ethyl-parathion has been used to generate a molecular model using ProMod software. Docking studies showed the involvement in the binding pocket of CDR H₃, as expected, but also of CDR L₂ and of small areas of the framework region of the light chain, based on the Kabat definition of CDRs. The majority of the L₂ contacts do, however, fall within a recently proposed re-definition of L₂. The validity of the model was supported by comparing docking studies of structurally related pesticides with cross-reaction data from an ELISA.