Combining site specificity of monoclonal antibodies to the organophosphate hapten Soman

The combining site specificities of eight monoclonal antibodies raised against the organophosphorous-containing hapten Soman are compared to monoclonal antibodies specific for a naturally occurring organophosphorous compound, phosphocholine (PC). Although these haptens share some structural and spatial features, differences in their chemical structures, most notably the presence or absence of a positive charge, appear to prevent significant cross-reactivity between antibodies specific for each. The murine memory response to PC-KLH has been shown previously to be characterized by the presence of two major groups of antibodies differentiated on the basis of their specificity for free PC and for the nitrophenyl derivative of PC, nitrophenylphosphocholine (NPPC). Interestingly, two groups of hybridoma antibodies were detected in the immune response to Soman-KLH which possess differential specificity for Soman and for a nitrophenyl derivative of Soman.