Binding of caffeic acid to human serum albumin by the retention data and frontal analysis.

A new mathematical model and frontal analysis were used to characterize the binding behavior of caffeic acid to human serum albumin (HSA) based on high-performance affinity chromatography. The experiments were carried out by injecting various mole amounts of the drug onto an immobilized HSA column. They indicated that caffeic acid has only one type of binding site to HSA on which the association constant was 2.75 × 10(4) /m. The number of the binding site involving the interaction between caffeic acid and HSA was 69 nm. The data obtained by the frontal analysis appeared to present the same results for both the association constant and the number of binding sites. This new model based on the relationship between the mole amounts of injection and capacity factors assists understanding of drug-protein interaction. The proposed model also has the advantages of ligand saving and rapid operation.