PT - JOURNAL ARTICLE AU - J. F. RODRIGUES DE MIRANDA AU - C. W. HILBERS TI - A Nuclear Magnetic Resonance Study of the Kinetics of the Binding of the Renal Contrast Medium Acetrizoate to Albumin DP - 1976 Mar 01 TA - Molecular Pharmacology PG - 279--290 VI - 12 IP - 2 4099 - http://molpharm.aspetjournals.org/content/12/2/279.short 4100 - http://molpharm.aspetjournals.org/content/12/2/279.full SO - Mol Pharmacol1976 Mar 01; 12 AB - NMR line broadening and shift measurements in conjunction with dialysis binding experiments have been performed on the acetrizoate-bovine serum albumin (BSA) system. Two types of binding sites have been detected, for which the binding constants and the kinetic parameters have been determined. The association rate constants for the formation of both types of acetrizoate-BSA complexes appear not to be diffusion-limited. The kinetic parameters are discussed in relation to the renal tubular excretion of acetrizoate. The acetrizoate molecules bound to the second class of binding sites retain a considerable amount of freedom with respect to the albumin molecule. It is pointed out that some earlier NMR studies concerning the motional freedom of individual molecular groups of pharmacologically interesting molecules on protein surfaces should be regarded with caution. ACKNOWLEDGMENTS The technical assistance of A. J. G. M. Henderix and J. W. M. van Kessel is gratefully acknowledged.