The effects of cholesterol and β-sitosterol on the structure of saturated diacylphosphatidylcholine bilayers.
The structures of DMPC and DPPC bilayers in unilamellar liposomes, in the presence of 33.3 mol% cholesterol or the plant sterol β-sitosterol, have been studied by small-angle neutron scattering. The bilayer thickness d(L) increases in a similar way for both sterols. The repeat distance in multilamellar liposomes, as determined by small-angle X-ray diffraction, is larger in the presence of β-sitosterol than in the presence of cholesterol. We observe that each sterol modifies the interlamellar water layer differently, cholesterol reducing its thickness more efficiently than β-sitosterol, and conclude that cholesterol suppresses bilayer undulations more effectively than β-sitosterol.
Gallová
Jana
J
Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University, 83232 Bratislava, Slovakia. gallova@fpharm.uniba.sk
Uhríková
Daniela
D
Kučerka
Norbert
N
Doktorovová
Slavomíra
S
Funari
Sérgio S
SS
Teixeira
José
J
Balgavý
Pavol
P
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D053838:Scattering, Small Angle; D012855:Sitosterols / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
D008051:Lipid Bilayers; D008081:Liposomes; D012855:Sitosterols; D015060:1,2-Dipalmitoylphosphatidylcholine; C025473:gamma-sitosterol; D002784:Cholesterol