Quantum Mechanical Investigation into the Fine Specificity of the Antibodies to Soman, BE2 and CC1

摘要

In an investigation of the molecular basis for the differences in inhibition of antibodies to soman by challenge compounds, three compounds were selected for characterization by quantum chemical methods. Molecular geometries of model compounds were optimized using the semi-empirical INDO/S method with energy gradient. Molecular energies, formal charges, electron density distributions, and electrostatic potentials were calculated using the INDO/S method and using ab initio self-consistent field (SCF) methods. These calculations describe well the bulk stereoelectronic properties of the model compounds and show clearly the precise geometry in the P-0 double bond region and the stereoelectronic requisites which favor recognition of soman by the antibodies. When they are obtained for each compound in the series of compounds used to challenge the antibodies to soman, molecular parameters obtained by quantum chemical calculations such as those described here can be used to correlate biological activity and molecular structure.