Identification of the ouabain-binding peptide of (nak)-atpase).
The [3H]-ouabain-(NaK)-ATPase complex when treated in the cold with sodium dodecyl sulfate (SDS) dissociates into a larger and smaller peptide called alpha and beta, resp.. Analysis of the released peptides by SDS-polyacrylamide gel electrophoresis reveals that [3H]-ouabain co-migrates with the alpha-peptide only, being apparently identic with the ouabain receptor molecule. The percentage occupancy of the receptor peptide with [3H]-ouabain can be increased up to 90% evidencing the stabilization of the [3H]-ouabain-alpha-peptide complex by SDS-exposure and release from the oligomeric enzyme. A hypothetic explanation for the seemingly paradoxical stabilising effect of SDS on the complex is offered.
D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D004734:Energy Metabolism; D007668:Kidney / Q000201:enzymology; D010042:Ouabain; D010455:Peptides / Q000032:analysis; D011485:Protein Binding; D013552:Swine
D010455:Peptides; D010042:Ouabain; D000251:Adenosine Triphosphatases