Bilayer thickness in unilamellar extruded 1,2-dimyristoleoyl and 1,2-dierucoyl phosphatidylcholine vesicles: SANS contrast variation study of cholesterol effect.
Small-angle neutron scattering on extruded unilamellar vesicles in water was used to study bilayer thickness when cholesterol (CHOL) was added at 44.4 mol% to 1,2-dimyristoleoylphosphatidylcholine (diC14:1PC) and 1,2-dierucoylphosphatidylcholine (diC22:1PC) bilayers. Using the (1)H(2)O/(2)H(2)O contrast variation and the small-angle form of Kratky-Porod approximation, the bilayer gyration radii at infinite contrast R(g,infinity) and the bilayer thickness parameters d(g,infinity) = 12(0.5)R(g,infinity) were obtained at 30 degrees C. Addition of cholesterol to diC14:1PC increased the d(g,infinity) from 3.72 +/- 0.02 to 4.26 +/- 0.01 nm, while in the diC22:1PC bilayers the d(g,infinity) change observed was within the experimental error: +0.23 +/- 0.23 nm.
Faculty of Pharmacy, Comenius University, Odbojárov 10, 83232 Bratislava, Slovakia. gallova@fpharm.uniba.sk
Jana
J
Gallová
Daniela
D
Uhríková
Mária
M
Hanulová
José
J
Teixeira
Pavol
P
Balgavý
D002784:Cholesterol / Q000032:analysis / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D008051:Lipid Bilayers / Q000032:analysis / Q000737:chemistry*; D046911:Macromolecular Substances / Q000032:analysis / Q000737:chemistry; D008956:Models, Chemical; D033363:Neutron Diffraction / Q000379:methods*; D010713:Phosphatidylcholines / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D008051:Lipid Bilayers; D046911:Macromolecular Substances; D010713:Phosphatidylcholines; D014867:Water; C500050:1,2-dierucoyl phosphatidylcholine; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine