Each Phaseolus vulgaris isolectin exists in five electrophoretic forms related to the number of metal ions bound per molecule

Analysis of the pH 8.3 electrophoresis of the Phaseolus vulgaris seed lectins suggests that each of the five isolectins exists in five different forms. Incubations of the lectins in the presence of EDTA or of metal ions such as Mn²⁺, Mg²⁺, Co²⁺ and Ni²⁺ shows that their different electrophoretic behaviours are related to the binding of metal ions to the molecules.Determinations of the isolectin metal content by atomic absorption measurements demonstrate that at pH 8.3 their five electrophoretic forms are related to the number of subunits (0, 1, 2, 3 or 4) which contain metal ions in the tetrameric molecules.