Structure-activity relationships in immunochemistry—V

Substituent constants and regression analysis have been used to formulate structure-activity relationships for the interaction of two groups of haptens (phenylsuccinamates and pyridines) with anli-3-azopyridine antibodies. The strength of the interactions of both types of haptens is primarily governed by dispersion forces of the substituents as modeled by molar refractivity. The most important conclusion is that the binding sites of the antibody do not appear to be typically hydrophobic in so far as this can he assessed by the parameter π which suggests that the binding sites are composed of hydrophilic ami no acid residues rather than hydrophobic. This result confirms a similar earlier finding for benzoates acting as haptens.