[Purification of a membrane protein modifying the sensitivity of Na+/K+ ATPase to ouabain from a supernatant of plasma membrane treated with EDTA]

Abstract

A membrane protein of M. W. 32,000 D and pI 5 has been purified from EDTA-treated plasma membrane supernatants by Page without detergents. These membranes are purified from the MF2S cell line issued from the murine plasmacytoma MOPC 173. The purified protein was able to induce a 300 fold increase in the Na+/K+ ATPase resistance to ouabaïn thus mimicking the original resistance of the enzyme to the drug.