MITOGENICITY OF ISOLECTINS ISOLATED FROM PHASEOLUS-VULGARIS L VAR ATHROPURPUREA IN RAT SPLEEN LYMPHOCYTES

The lymphoblastic transformation capacity of rat spleen lymphocytes ha s been evaluated by stimulating the cells with isolectins isolated fro m raw seeds of Phaseolus vulgaris L. var. athropurpurea (PHVa). PHVa a lbumin and globulin fractions (AF and GF) and the isolectins E4+E3L, E 2L2, EL3 and L4+albumins (where E and L indicate erythroagglutinating and leucoagglutinating activities respectively) were isolated, purifie d and identified by gel chromatography and sodium dodecyl sulphate-pol yacrylamide gel electrophoresis (SDS-PAGE). It has been found, first, that the four isolectins were exclusively contained in PHVa AF; second , that the highest mitogenic activity displayed by these glycoproteins was obtained after three days of incubation; and, finally, that all t he isolectins showed a similar mitogenic activity, the classical gauss ian curves for isolectin dilutions versus mitogenic activity being sim ilar for all the isolectins tested, regardless of the predominance of either the E or L subunits.