title: X-ray Absorption Spectroscopy and Spectromicroscopy of Supported Lipid Bilayers.
abstract: The C 1s, O 1s, and N 1s X-ray absorption spectra of three lipid species, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and 1,2-dioleoyl-3-trimethylammonium-propane (chloride salt) (DOTAP), have been recorded using transmission detection in a scanning transmission X-ray microscope. The spectra are presented on an absolute intensity scale (i.e., optical density per nm) to allow their use as reference standards for spectromicroscopic analysis of supported lipid bilayers. Examples of C 1s based spectromicroscopic mapping of saturated and unsaturated domains in dry lipid bilayers of DOPC and DSPC at several compositions are presented. The results are compared with fluorescence microscopy of the same area. Challenges for extending this work to studies of wet lipid bilayers interacting with antimicrobial peptides are discussed.
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Jonathan D
authors.identifier: 0000-0002-4370-4425
authors.initials: JD
authors.lastname: West
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Sokunthearath
authors.identifier: 0000-0002-9106-8160
authors.initials: S
authors.lastname: Saem
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Jose
authors.identifier: 0000-0002-4811-3085
authors.initials: J
authors.lastname: Moran-Mirabal
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Adam P
authors.identifier: 0000-0002-1598-7886
authors.initials: AP
authors.lastname: Hitchcock
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D056928:X-Ray Absorption Spectroscopy
chemical_list: D023181:Antimicrobial Cationic Peptides; D008051:Lipid Bilayers