The interaction of serum albumins with various drugs in aqueous solution. Gel permeation, calorimetric, and fluorescence data.

Thermodynamic data relative to the reversible interaction between human or bovine serum albumin and some organic ligands (S- and R-warfarin, d- and l-oxazepam hemisuccinate, phenyl-butazone, fluorescein) in dilute aqueous solution were determined by means of gel permeation chromatography and microcalorimetric measurements. From an analysis of these data and on the basis of fluorescence titrations the identity of the "primary" binding site on the proteins for some ligands was evidenced, while in other cases a cooperative binding of two different ligands to different binding sites could be discerned.