[Studies on the mechanism of activation of lymphocyte membrane ATP-ases by concanavalin A (author's transl)].

The ouabain-sensitive and ouabain-intensitive ATP-ases of intact lymphocytes, and of the lymphocyte microsomal fraction and a purified plasma membrane fraction, are all activated by concanavalin A. The Na+, K+, and Mg+-dependence of the plasma membrane ATP-ases were defined at different substrate concentrations. Enzyme activation was rather greater at lower K+ concentrations. From these studies it appears improbable, but not impossible, that concanavalin A exerts an allosteric effect on the ATP-ases.