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-Structure paper
Title | Structure of a cholinergic cell membrane. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 119, Issue 34, Page e2207641119, Year 2022 |
Publish date | Aug 23, 2022 |
Authors | Nigel Unwin / |
PubMed Abstract | Cell membranes are complex assemblies of proteins and lipids making transient or long-term associations that have yet to be characterized at a molecular level. Here, cryo-electron microscopy is ...Cell membranes are complex assemblies of proteins and lipids making transient or long-term associations that have yet to be characterized at a molecular level. Here, cryo-electron microscopy is applied to determine how phospholipids and cholesterol arrange between neighboring proteins (nicotinic acetylcholine receptors) of cholinergic membrane. The lipids exhibit distinct properties in the two leaflets of the bilayer, influenced by the protein surfaces and by differences in cholesterol concentration. In the outer leaflet, the lipids show no consistent motif away from the protein surfaces, in keeping with their assumed fluidity. In the inner leaflet, where the cholesterol concentration is higher, the lipids organize into extensive close-packed linear arrays. These arrays are built from the sterol groups of cholesterol and the initial saturated portions of the phospholipid hydrocarbon chains. Together, they create an ordered ∼7 Å-thick "skin" within the hydrophobic core of the bilayer. The packing of lipids in the arrays appears to bear a close relationship to the linear cholesterol arrays that form crystalline monolayers at the air-water interface. |
External links | Proc Natl Acad Sci U S A / PubMed:35969788 / PubMed Central |
Methods | EM (helical sym.) |
Resolution | 5.5 Å |
Structure data | EMDB-14942: Map1 from paper entitled: Structure of a cholinergic cell membrane EMDB-14946: Map2 from paper entitled: Structure of a cholinergic cell membrane |
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