ROLE OF TRANSPORT PHENOMENA IN ION BINDING STUDIES OF SERUM ALBUMIN

Two hypotheses previously suggested to explain the apparent dependency on protein concentration of equilibrium dialysis measured binding of long-chain ionic ligands to bovine serum albumin have been tested and disproved. Of greater importance, it is shown that the apparent protein concentration effect was an experimental artifact which originated in the anomalously slow approach to equilibrium with these ligands under the conditions of the earlier experiments. The effects of protein concentration, ligand size, supporting electrolyte, and temperature on the approach to dialysis equilibrium is examined. Hitherto unobserved and only partially understood kinetic anomalies occur when ionic ligands of high affinity are dialyzed into protein solutions which are appreciably more concentrated than 0.1%. © 1969, American Chemical Society. All rights reserved.