Quantitative Relationships Between Protein Binding Affinities And Physico-Chemical And Structural Parameters Of Some Aniline Derivatives
The binding of a series of aniline derivatives to bovine serum albumin was investigated using fluorescence spectroscopic technique. Nineteen physico-chemical and structural parameters of drugs could be divided into four groups: steric, electronic, hydrophobic and molecular connectivity parameters. In order to understand the binding mechanism and to predict binding affinity, association constants for drug-protein binding have been correlated to physico-chemical and structural parameters of drugs using statistical methods. Significant correlation could only be obtained on removing from analysis the two relatively low molecular weight drugs, benzocaine and paracetamol. Hydrophobicity of drug was not found to be a significant parameter. The size of the drug molecule and electrostatic interactions play a major role in the binding of these drugs to serum albumin. Quadratic equations gave a better fit of the data. Quantitative relationships between association constant for drug-protein binding and various statistically significant physicochemical and structural parameters of drugs were obtained. The relationships can be useful in the prediction of association constants.