title: Condensed lamellar phase in ternary DNA-DLPC-cationic gemini surfactant system: a small-angle synchrotron X-ray diffraction study.
abstract: We report on a small-angle synchrotron X-ray diffraction study of dilauroylphosphatidylcholine (DLPC) liposomes aggregated with high molecular DNA in the presence of 1,4-butanediammonium-N,N'-dilauryl-N,N,N',N'-tetramethyl gemini surfactant cations (C12GS). The aggregates prepared at the DLPC/C12GS/DNA phosphate group=2:1:1.6 molar ratio in 0.0015 mol x l(-1) NaCl aqueous solution exhibit Bragg reflections due to lamellar lipid bilayer stacking and the Bragg reflection typical of one-dimensional DNA lattice with parallel strands intercalated between lipid bilayers. In this condensed fluid lamellar L(alpha)(c) phase, the interactions between DNA and charged bilayers damp the thermally induced bilayer undulations. The diffraction data obtained with the mixture of DLPC liposomes and DNA (at DNA phosphate group/DLPC=0.8:1 molar ratio) indicate a DNA-lipid interaction in the absence of C12GS.
authors.affiliation: Department of Physical Chemistry of Drugs, Faculty of Pharmacy, J A Comenius University, Odbojárov 10, SK-832 32, Bratislava, Slovak Republic.
authors.forename: Daniela
authors.initials: D
authors.lastname: Uhríková
authors.forename: Gert
authors.initials: G
authors.lastname: Rapp
authors.forename: Pavol
authors.initials: P
authors.lastname: Balgavý
mesh_terms: D000818:Animals; D002412:Cations; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D004655:Emulsions; D006358:Hot Temperature; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D015233:Models, Statistical; D008970:Molecular Weight; D010713:Phosphatidylcholines / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D002412:Cations; D004655:Emulsions; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C015153:1,2-dilauroylphosphatidylcholine; D004247:DNA; C427203:calf thymus DNA