title: Non-uniform distribution of phospholipids in (Na+ + K+)-ATPase-rich membranes from Torpedo marmorata electric organ evidenced by spin-spin interactions between spin-labeled phospholipids.
abstract: (Na+ + K+)-ATPase membranes from Torpedo marmorata electric organ were labeled with high concentrations of paramagnetic phospholipid analogs (up to 5 mol of spin labels for 100 mol of endogeneous phospholipids). The mobile lipid bilayer component of the complex resonance spectra obtained showed low-field linewidth broadening due to spin-spin interactions; this was used as a measure of probe concentration in this compartment. Our results show that in the lipid shell surrounding the protein, there is a considerable enrichment in negatively charged phospholipids over neutral ones.
mesh_terms: D000818:Animals; D004557:Electric Organ / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D008563:Membrane Lipids / Q000302:isolation & purification*; D010743:Phospholipids / Q000302:isolation & purification*; D000254:Sodium-Potassium-Exchanging ATPase / Q000302:isolation & purification*; D013113:Spin Labels; D014101:Torpedo
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids; D013113:Spin Labels; D000254:Sodium-Potassium-Exchanging ATPase