The relationship between metal ion content and mitogenicity of PHA-L4 isolectin as determined by agarose...

The lectin (PHA) from Phaseolus vulgaris is a tetrameric metalloprotein which exists as 5 different isolectins. An agarose electrophoretic assay is described that can distinguish between metallized and demetallized PHA. The assay has been employed for the analysis of 5 different preparations of the isolectin PHA-L4, and the preparations have subsequently been tested for their ability to induce lymphocyte transformation. A reverse correlation was found between the relative amount of irreversibly demetallized isolectin, as determined by agarose electrophoresis and the mitogenic activity of the preparation. The degree of irreversible demetallization seemed to be dependent on the preparation method used. One method gave 25% and another 100% demetallization of the isolectins. The assay was found to be a rapid and simple way to test the relative amount of mitogenically active lectin present in a preparation.