CAPILLARY AFFINOPHORESIS OF PEA LECTIN WITH POLYLIGANDED AFFINOPHORE - A MODEL STUDY OF DIVALENT-POLYVALENT INTERACTIONS

Affinophoresis is a type of affinity electrophoresis using an affinoph ore, a soluble ionic carrier bearing affinity ligand(s). It was report ed previously that an affinophore, prepared by coupling multiple p-ami nophenyl alpha-D-mannoside ligands to a part of the carboxyl groups of succinylated polylysine, specifically changed the mobility of pea lec tin in agarose gel. The affinophoresis of this divalent lectin with th e polyliganded affinophore was investigated by using capillary electro phoresis. Analysis of the mobility change of the lectin in the presenc e of differently modified affinophores showed that the affinity was la rger for affinophores having higher ligand density. Analysis of the in hibition of the mobility change by a neutral ligand, with a known affi nity constant for the lectin, allowed estimation of the contributions of monovalent and divalent interactions to the binding in the lectin-a ffinophore complex. The proportion of divalent complexes was greater f or affinophores having higher ligand density. This approach to estimat e the contribution of divalency in complex formation should be general ly applicable to the analysis of divalent interactions with different techniques other than electrophoresis.