A UNIFIED PARTITION-COEFFICIENT THEORY FOR CHROMATOGRAPHY, IMMOBILIZED ENZYME-KINETICS, AND AFFINITY-CHROMATOGRAPHY

A unified treatment of systems containing immobilized biochemical and chromatographic systems was developed from basic thermodynamic considerations of partitioning in biphasic systems. Division of the overall partitions coefficient into electrostatic and nonelectrostatic interactions provided an effective stratagem for analysis of these systems. The properties of both strong and weak ionogenic matrices were explored. It was Found that the matrix charge concentration and the bulk solutions pH and ionic strength completely determine the electrostatic partition coefficient. Hence, the relationships developed allow prediction of partition coefficients from readily obtainable experimental parameters. It was also shown that even at low concentrations, the presence of immobilized protein can alter the properties of the matrix phase. However, a weak ionogenic matrix has an unusual property which allows for a biological switching device. Ina characteristics pH range, such matrices will maintain a constant micro environmental pH while the partitioning of a substrate ion is greatly variable. Finally, the theoretical treatment suggests simple procedures for determination of binding constants from affinity or adsorption chromatography. © 1981 John Wiley & Sons, Inc.