title: Metal ion binding to phospholipid bilayers evaluated by microaffinity chromatography.
abstract: Group I and II ion binding to phospholipid membranes was evaluated by affinity chromatography utilizing a new stationary phase system based on lipid bilayers supported within large-pore particles composed of Stöber silica spheres. Using an inductively coupled plasma mass spectrometer for detection, robust determination of binding selectivity within group II ions is achieved with capillary columns containing nanomole quantities of lipid and using picomoles of metal analyte. Columns with a unique lipid formulation can be prepared within three hours using a solvent-casting assembly method. The observable thermotropic phase behavior of dipalmitoylphosphatidylcholine has a significant effect on alkaline metal binding and demonstrates the dynamic nature of the supported bilayers. Of the group I ions, only lithium exhibits retention with neutral phosphatidylcholine bilayer stationary phases. A comparison of Stöber-based supports with two commercially available large-pore silicas reveals the effect that particle structure has on analyte accessibility to the bilayer surface as evaluated by retention per supported lipid mass.
authors.affiliation: Department of Chemistry & Biochemistry, Gonzaga University, Spokane, WA 99258, United States. Electronic address: rosse@gonzaga.edu.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Ross
authors.affiliation: Department of Chemistry & Biochemistry, Gonzaga University, Spokane, WA 99258, United States.
authors.forename: Christian
authors.initials: C
authors.lastname: Hoag
authors.affiliation: Department of Chemistry & Biochemistry, Gonzaga University, Spokane, WA 99258, United States.
authors.forename: Zach
authors.initials: Z
authors.lastname: Pfeifer
authors.affiliation: Department of Chemistry & Biochemistry, Gonzaga University, Spokane, WA 99258, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Lundeen
authors.affiliation: Department of Chemistry & Biochemistry, Gonzaga University, Spokane, WA 99258, United States.
authors.forename: Sarah
authors.initials: S
authors.lastname: Owens
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D002846:Chromatography, Affinity / Q000295:instrumentation / Q000379:methods*; D007477:Ions / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry; D013058:Mass Spectrometry; D008670:Metals / Q000737:chemistry*; D008863:Microspheres; D036103:Nanotechnology; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D007477:Ions; D008051:Lipid Bilayers; D008670:Metals; D010713:Phosphatidylcholines; D010743:Phospholipids; D015060:1,2-Dipalmitoylphosphatidylcholine; C081581:colfosceril palmitate; D012822:Silicon Dioxide; D008094:Lithium
keywords: Affinity chromatography; EggPC; ICP-MS; Phospholipid; Stöber silica; Zwitterionic ion chromatography