Research Article
G Rezaei Behbehani, A A Sab
Abstract
This study was designed to determine the structural changes of human serum albumin, HAS, in the presence of aspirin in H 2 O solutions at physiological pH 7. Isothermal titration calorimetry, ITC, at 298 and 310K, and curve-fitting procedures were applied to characterize the drug binding sites, the binding constants in the aspirin+HSA complexes. The heats obtained for aspirin+HSA interactions are reported and analyzed in terms of the extended solvation theory. It was indicated that there are a set of two identical and non-cooperative sites for aspirin. Calorimetric evidence showed that strong aspirin+HSA interaction occurs at very low aspirin concentration (0.007-0.084 mM), with overall binding constants of 2.76 × 10 6 M -1 and 9.3×10 5 M -1 at low and high aspirin concentration domains respectively.