Solubilization and further chromatographic purification of highly purified, membrane-bound Na,K-ATPase

Highly purified membrane-bound Na,K-ATPase from pig kidney outer medulla was dissolved in the non-ionic detergent C12E8. Chromatography of the dissolved material on a DEAE matrix yielded enzymatical material having a ouabain-binding capacity of 6.9 nmoles per mg protein (measured according to Lowry et al., with bovine serum albumin as standard). This material, which after addition of lipids had the same K+-phosphatase turnover as the membrane-bound enzyme, could consist entirely of live molecules with a molecular weight of 145 kDa, a value close to that expected for alpha beta-promoters of Na,K-ATPase.