Structure of functional Staphylococcus aureus alpha-hemolysin channels in tethered bilayer lipid membranes.

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TitleStructure of functional Staphylococcus aureus alpha-hemolysin channels in tethered bilayer lipid membranes.
Publication TypeJournal Article
Year of Publication2009
AuthorsMcGillivray, DJ, Valincius, G, Heinrich, F, Robertson, JWF, Vanderah, DJ, Febo-Ayala, W, Ignatjev, I, Lösche, M, Kasianowicz, JJ
JournalBiophys J
Volume96
Issue4
Pagination1547-53
Date Published2009 Feb 18
ISSN1542-0086
KeywordsBacterial Toxins, Gold, Hemolysin Proteins, Lipid Bilayers, Models, Molecular, Patch-Clamp Techniques, Spectrum Analysis, Staphylococcus aureus
Abstract

We demonstrate a method for simultaneous structure and function determination of integral membrane proteins. Electrical impedance spectroscopy shows that Staphylococcus aureus alpha-hemolysin channels in membranes tethered to gold have the same properties as those formed in free-standing bilayer lipid membranes. Neutron reflectometry provides high-resolution structural information on the interaction between the channel and the disordered membrane, validating predictions based on the channel's x-ray crystal structure. The robust nature of the membrane enabled the precise localization of the protein within 1.1 A. The channel's extramembranous cap domain affects the lipid headgroup region and the alkyl chains in the outer membrane leaflet and significantly dehydrates the headgroups. The results suggest that this technique could be used to elucidate molecular details of the association of other proteins with membranes and may provide structural information on domain organization and stimuli-responsive reorganization for transmembrane proteins in membrane mimics.

DOI10.1016/j.bpj.2008.11.020
Alternate JournalBiophys. J.
PubMed ID19217871
PubMed Central IDPMC2717257
Grant List1 P01 AG032131-01 / AG / NIA NIH HHS / United States
1 R01 RR14182 / RR / NCRR NIH HHS / United States
P01 AG032131-01A1 / AG / NIA NIH HHS / United States