Estimation of the number of enantioselective sites of bovine serum albumin using frontal chromatography.

On a column with bovine serum albumin (BSA) immobilized covalently to silica, the adsorption isotherms of the enantiomers of mandelic acid, tryptophan, 2-phenylbutyric acid, and N-benzoylalanine are measured using a buffered mobile phase. Knowing the amount of BSA immobilized on the column (36 mg), the ratio of the number of enantiomer molecules needed to saturate the enantioselective retention mechanism to the number of BSA molecules is determined. The mean of the set of eight enantiomers is 0.28. These data confirm that at most one enantioselective site exists for each BSA molecule for the kind of enantiomers studied.