title: Dynamic lipid-protein stoichiometry on E1 and E2 conformations of the Na+/K+ -ATPase.
abstract: Annular lipid-protein stoichiometry in native pig kidney Na+/K+ -ATPase preparation was studied by [125I]TID-PC/16 labeling. Our data indicate that the transmembrane domain of the Na+/K+ -ATPase in the E1 state is less exposed to the lipids than in E2, i.e., the conformational transitions are accompanied by changes in the number of annular lipids but not in the affinity of these lipids for the protein. The lipid-protein stoichiometry was 23 ± 2 (α subunit) and 5.0 ± 0.4 (β subunit) in the E1 conformation and 32 ± 2 (α subunit) and 7 ± 1 (β subunit) in the E2 conformation.
authors.affiliation: Instituto de Química y Fisicoquímica Biológicas and Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina.
authors.forename: Irene
authors.initials: I
authors.lastname: Mangialavori
authors.forename: Mónica R
authors.initials: MR
authors.lastname: Montes
authors.forename: Rolando C
authors.initials: RC
authors.lastname: Rossi
authors.forename: Natalya U
authors.initials: NU
authors.lastname: Fedosova
authors.forename: Jean Paul F C
authors.initials: JP
authors.lastname: Rossi
mesh_terms: D000818:Animals; D001665:Binding Sites; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D007668:Kidney / Q000201:enzymology*; D008055:Lipids / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000378:metabolism; D013552:Swine
chemical_list: D008055:Lipids; D008565:Membrane Proteins; D000254:Sodium-Potassium-Exchanging ATPase