Abstract
1. Lipid and protein composition of various Na, K-ATPase [EC 3. 6. 1. 3] preparations in the course of purification including highly purified preparations was estimated. The total amounts of neutral lipid, phospholipid, cerebroside, and ganglioside as well as the composition of neutral lipids and phospholipids were determined using mainly thin-layer-chromatography. SDS-polyacrylamide gel electrophoresis was carried out for the determination of polypeptide components. These analyses were designed to see the lipoprotein nature of this enzyme.
2. Variety of the lipid composition at various steps of purication was not so great as that of polypeptide components observed in a SDS-disc gel electrophoresis. However, it is evident that the relative phosphatidyl serine content increased with purification.
3. Pools of the three different Na, K-ATPase preparations which were obtained with AE-cellulose column chromatography and showed specific activities of 1, 000-1, 700 μ moles of inorganic phosphate released, hr-1, mg protein-1 had very large amounts of lipids compared with crude enzyme preparations, and their phospholipid compositions were also different from one another.
