title: Effects of gemini surfactants on egg phosphatidylcholine bilayers in the fluid lamellar phase.
abstract: The influence of 1,4-butanediamonium-N,N'-dialkyl-N,N,N',N'-tetramethyl dibromides (CmA, m = 7-16 is the number of alkyl carbons) on the egg yolk phosphatidylcholine (EYPC) bilayer thickness and lipid surface area at the bilayer-aqueous phase interface is studied using X-ray diffraction on fluid lamellar CmA + EYPC + H2O phases as a function of CmA:EYPC and H2O:EYPC molar ratios and the alkyl chain length m. At the constant CmA:EYPC = 0.4 and H2O:EYPC = 18 molar ratios, the CmA induced bilayer thickness decrease shows a minimum and the lipid surface area increase a maximum at the alkyl chain length m = 9. The obtained results are discussed in the context of a structural perturbation model of the cut-off effect in biological potencies of surfactants which occurs when increasing the alkyl substituent chain length above the critical value.
authors.affiliation: Faculty of Pharmacy, Comenius University, 83232 Bratislava, Slovak Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Dubnicková
authors.forename: Sergej
authors.initials: S
authors.lastname: Yaradaikin
authors.forename: Ivan
authors.initials: I
authors.lastname: Lacko
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Devínsky
authors.forename: Valentin
authors.initials: V
authors.lastname: Gordeliy
authors.forename: Pavol
authors.initials: P
authors.lastname: Balgavý
mesh_terms: D004530:Egg Yolk / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D008956:Models, Chemical; D015233:Models, Statistical; D010713:Phosphatidylcholines / Q000737:chemistry*; D012542:Scattering, Radiation; D014961:X-Ray Diffraction
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines