PCB and Related Compound Binding to the Ah Receptor(s) Theoretical Model Based on Molecular Parameters and Molecular Mechanics

A model previously developed for describing PCB binding to cytosol receptors is tested with binding data from a set of PCBs [Bandiera et al., Biochem. Pharmacol. 32: 3803–3813 (1983)] which exhibit a broad range of intermolecular forces. The binding of molecules which would be expected to be dominated by dispersive interactions is correlated well with binding constants determined by polarizability and stacking distance parameters. The binding data for molecules which have substituents capable of exerting other electronic effects on binding correlate less well as expected. The stacking model was shown to be consistent with the minimum separation distances found by molecular mechanics. This simple model based on molecular parameters is a more universally applicable model for Ah receptor‐aromatic hydrocarbon binding since it can explain the exceptions found for the previous rectangular (3 × 10Å) box model.