[A comparative study of the properties of ouabain-sensitive phosphatase in rat erythrocyte ghosts and spectrin-free membranes].

The removal of the membrane skeleton proteins (MSP), chiefly spectrin and actin, from the rat erythrocyte ghosts was shown to result in a decrease of both the total Na, K-ATPase activity and a partial reaction of the enzyme, namely the phosphatasic one. Besides, modulating effects of the effectors promoting the enzyme conformational transitions (ATP and Mg2+) on the ouabain-sensitive K-phosphatase is changed. For instance, a pronounced activation of the K-phosphate in a high-potassium medium in the presence of 1 mM ATP disappeared and the degree of the enzymatic activity enhancement in response to increasing MgCl2 concentrations (from 1.5 to 6 mM) is decreased. The data obtained are discussed from the viewpoint of possible involvement of the erythrocyte MSP in the catalytic of Na, K-ATPase.