title: Controlling the charge and organization of anionic lipid bilayers: effect of monovalent and divalent ions.
abstract: It is shown that the organization of lipid bilayers containing phosphatidic acid (PA) and phosphatidlycholine (PC) can be controlled by altering the monovalent and divalent ion concentrations. At high pH and/or calcium concentration, 1:1 Ca(2+)-PA(2-) complexes form; these complexes demix, and PA-rich and PC-rich regions are observable with epifluorescence microscopy. The results are compared with predictions from electrostatic theory. It is noted that the complex formation correlates in a roughly linear fashion with the monovalent/divalent ion ratio, a parameter that cells adjust.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Lamberson
authors.forename: Lee R
authors.initials: LR
authors.lastname: Cambrea
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Hovis
mesh_terms: D000838:Anions; D002118:Calcium / Q000737:chemistry; D002412:Cations; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers; D008856:Microscopy, Fluorescence; D010712:Phosphatidic Acids / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry
chemical_list: D000838:Anions; D002412:Cations; D008051:Lipid Bilayers; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D002118:Calcium