Dynamic protein-lipid stoichiometry on E1 and E2 conformations of the Na+/K+-ATPase

IRENE MANGIALAVORI ; MÓNICA MONTES; ROLANDO ROSSI; FEDOSOVA NATALYA; JUAN PABLO F.C. ROSSI

FEBS LETTERS

ELSEVIER SCIENCE BV

Lugar: Reino Unido; Año: 2011 vol. 585 p. 1153 - 1157

0014-5793

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 (a subunit) and 5.0 ± 0.4 (b subunit) in the E1 conformation and 32 ± 2 (a subunit) and 7 ± 1 (b subunit) in the E2 conformation.