Hydrolysis of organophosphorus nerve agent soman by the monoclonal antibodies elicited against an oxyphosphorane hapten

Abstract

The antibody-mediated hydrolysis of the nerve agent O-1,2,2-trimethylpropyl methylphosphonofluoridate (soman) 1 has now been established with two monoclonal antibodies raised against the cyclic pentacovalent methyloxyphosphorane hapten 10 that mimics the pentacoordinated trigonal bipyramidal transition-state of the reaction. The hydrolysis reaction was studied using molecular orbital methods at the MP2/6-31 + G*//HF/6-31 + G* level of accuracy. According to the ab initio calculations, the reaction seems to proceed via three separate transition-states. The calculations are in good agreement with the experimental results. The 1,3-dioxabenzophosphole hapten 10 was synthesized, coupled to the carrier protein and the antibodies were obtained by the hybridoma technique. Two antibodies, DB-108P and DB-108Q were found to enhance the rate of soman hydrolysis and they were kinetically characterised.