title: Deuterium Labeling Strategies for Creating Contrast in Structure-Function Studies of Model Bacterial Outer Membranes Using Neutron Reflectometry.
abstract: Studying the outer membrane of Gram-negative bacteria is challenging due to the complex nature of its structure. Therefore, simplified models are required to undertake structure-function studies of processes that occur at the outer membrane/fluid interface. Model membranes can be created by immobilizing bilayers to solid supports such as gold or silicon surfaces, or as monolayers on a liquid support where the surface pressure and fluidity of the lipids can be controlled. Both model systems are amenable to having their structure probed by neutron reflectometry, a technique that provides a one-dimensional depth profile through a membrane detailing its thickness and composition. One of the strengths of neutron scattering is the ability to use contrast matching, allowing molecules containing hydrogen and those enriched with deuterium to be highlighted or matched out against the bulk isotopic composition of the solvent. Lipopolysaccharides, a major component of the outer membrane, can be isolated for incorporation into model membranes. Here, we describe the deuteration of lipopolysaccharides from rough strains of Escherichia coli for incorporation into model outer membranes, and how the use of deuterated materials enhances structural analysis of model membranes by neutron reflectometry.
authors.affiliation: National Deuteration Facility, Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales, Australia. Electronic address: abn@ansto.gov.au.
authors.forename: Anton P
authors.initials: AP
authors.lastname: Le Brun
authors.affiliation: ISIS Neutron Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom.
authors.forename: Luke A
authors.initials: LA
authors.lastname: Clifton
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales Australia.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Holt
authors.affiliation: National Deuteration Facility, Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Holden
authors.affiliation: Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne, United Kingdom.
authors.forename: Jeremy H
authors.initials: JH
authors.lastname: Lakey
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D003903:Deuterium / Q000737:chemistry; D041961:Deuterium Exchange Measurement; D004926:Escherichia coli / Q000737:chemistry* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry; D008958:Models, Molecular; D009502:Neutrons; D013194:Staining and Labeling / Q000379:methods*; D013329:Structure-Activity Relationship
chemical_list: D001425:Bacterial Outer Membrane Proteins; D008070:Lipopolysaccharides; D003903:Deuterium
keywords: Deuteration; Lipopolysaccharide; Model membrane; Neutron reflectometry; Outer membrane