STUDIES ON MECHANISM OF ACTIVATION OF LYMPHOCYTE MEMBRANE ATP-ASES BY CONCANAVALIN-A

Abstract

The ouabain-sensitive and ouabain-intensitive ATPases of intact lymphocytes [human], and of the lymphocyte microsomal fraction and a purified plasma membrane fraction, were all activated by concanavalin A. The Na+, K+ and Mg+-dependence of the plasma membrane ATPases were defined at different substrate concentrations. Enzyme activation was rather greater at lower K+ concentrations. Concanavalin A apparently may exert an allosteric effect on the ATPases.