Measurement of binding constants by capillary electrophoresis

Abstract

The assumptions inherent in a capillary electrophoresis procedure for evaluating binding constants for interactions between lectins and charged polysaccharides [S. Honda et al., J. Chromatogr., 597 (1992) 377] have been reappraised. Whereas the results were originally interpreted on the basis that the lectin-carbohydrate interaction was restricted to 1:1 complex formation, a more plausible interpretation is shown to be that an approximately constant incremental difference separates the mobilities of the successive complexes formed as the result of saccharide binding to equivalent and independent sites on the lectin. The parameter that is determined by capillary electrophoresis should thus be regarded as the intrinsic binding constant.