Study of Kirkwood-Buff integrals of selected polar and nonpolar amino acids in aqueous-streptomycin sulphate solutions at 298.15 K

Abstract

The Kirkwood-Buff (K-B) integrals can play pivotal role in understanding the physiochemical action of drugs on proteins. The Kirkwood-Buff theory can be used to characterize the intermolecular interactions of amino acids with drug by directly calculating G₁₁, G₂₂ and G₁₂ parameters which represents solute-solute, solvent-solvent and solute-solvent interaction respectively. The K-B integrals of nonpolar amino acids glycine, l-alanine, l-valine, l-isoleucine and polar amino acids l-histidine and l-arginine in aqueous-streptomycin sulphate solutions (1% and 2% streptomycin sulphate in water, w/w) have been calculated from experimental data of ultrasonic speed and density at 298.15 K. All the results obtained by theoretical calculations are in good agreement with that of experimental results.