title: Lipid-protein stoichiometries in a crystalline biological membrane: NMR quantitative analysis of the lipid extract of the purple membrane.
abstract: The lipid/protein stoichiometries of a naturally crystalline biological membrane, the purple membrane (PM) of Halobacterium salinarum, have been obtained by a combination of (31)P- and (1)H-NMR analyses of the lipid extract. In total, 10 lipid molecules per retinal were found to be present in the PM lipid extract: 2-3 molecules of phosphatidylglycerophosphate methyl ester (PGP-Me), 3 of glycolipid sulfate, 1 of phosphatidylglycerol, 1 of archaeal glycocardiolipin (GlyC), 2 of squalene plus minor amounts of phosphatidylglycerosulfate (PGS) and bisphosphatidylglycerol (archaeal cardiolipin) (BPG) and a negligible amount of vitamin MK8. The novel data of the present study are necessary to identify the lipids in the electron density map, and to shed light on the structural relationships of the lipid and protein components of the PM.
authors.affiliation: Dipartimento di Fisiologia Generale ed Ambientale, Università di Bari, Via Amendola 165/a, 70126, Bari, Italy. a.corcelli@biologia.uniba.it
authors.forename: Angela
authors.initials: A
authors.lastname: Corcelli
authors.forename: Veronica M T
authors.initials: VM
authors.lastname: Lattanzio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mascolo
authors.forename: Paride
authors.initials: P
authors.lastname: Papadia
authors.forename: Francesco
authors.initials: F
authors.lastname: Fanizzi
mesh_terms: D019843:Archaeal Proteins / Q000032:analysis; D001436:Bacteriorhodopsins / Q000032:analysis*; D002308:Cardiolipins / Q000032:analysis; D003459:Crystallins / Q000378:metabolism*; D019617:Halobacterium salinarum; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010715:Phosphatidylglycerols / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D018717:Purple Membrane / Q000737:chemistry* / Q000378:metabolism; D013185:Squalene / Q000032:analysis
chemical_list: D019843:Archaeal Proteins; D002308:Cardiolipins; D003459:Crystallins; D008055:Lipids; C407124:PGP-Me; D010715:Phosphatidylglycerols; D010743:Phospholipids; D001436:Bacteriorhodopsins; D013185:Squalene