Protein-binding of ascorbic acid: 1. Binding to bovine serum albumin.

A modified method is described for investigating the binding of ascorbic acid (AA) to bovine serum albumin (BSA) by the use of dynamic dialysis. The results demonstrate that reversible complex formation occurs between AA and BSA. Non-Linear least-squares curve fitting procedures were used to construct a Scatchard plot. The values of the limiting slopes demonstrated two classes of independent binding sites which have different intrinsic binding constants. The binding strengths of the primary sites were about 300 times greater than those of the secondary sites, but the secondary sites were about 42 times more numerous. The pathophysiological implications are discussed.