Interaction of Ortho-iodohippurate with Bovine Serum Albumin

Alice Lázníčková (laznicko@faf.cuni.cz), Josef Dolejš

Department of Biophysics and Physical Chemistry, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic

Summary

The binding of radiolabelled ortho-iodohippurate to bovine serum albumin was studied by equilibrium dialysis at 24 °C. The free drug fraction was dependent on total ortho-iodohippurate concentration. The association constants to primary and secondary binding sites were calculated by non-linear itterative regression analysis. The analysis consisted of computing free and bound ortho-iodohippurate for a range from 10^-5 to 10^-2 mol/l. One primary binding site with association constant K₁ = 3.96×10^-3 l/mol and approximatelly four low affinity binding sites (K₂ = 0.0774 l/mol) were calculated. This finding is in agreement with general notion of two types of the binding sites on albumin molecule for the binding of acidic drugs.