The binding of salicylic acid and acetylsalicylic acid to human serum albumin

Abstract

The binding of salicylic acid (SA) and acetylsalicylic acid (ASA) to human serum albumin (HSA) has been further elucidated through use of the gel filtration technique of Hummel. The method is analogous in principle to equilibrium dialysis and is suited to study the binding of small molecules to macromolecules. The bound complex is placed on a column previously saturated with a solution of the small molecule and is eluted with the same concentration of small molecule. Results using this method show the HSA-ASA bond to be strong in comparison to the relatively weak binding of SA to HSA. Evidence points to the conclusion that the HSA molecule has a relatively large number of weak binding sites for SA in comparison to a smaller number of stronger binding sites for ASA. Time studies indicated that ASA equilibrium binding was reached only after 120–150 hours of contact with HSA.