Stiffening effect of cholesterol on disordered lipid phases: a combined neutron spin echo + dynamic light scattering analysis of the bending elasticity of large unilamellar vesicles.
In this study, the center-of-mass diffusion and shape fluctuations of large unilamellar 1-palmitoyl-2-oleyl-sn-glycero-phosphatidylcholine vesicles prepared by extrusion are studied by means of neutron spin echo in combination with dynamic light scattering. The intermediate scattering functions were measured for several different values of the momentum transfer, q, and for different cholesterol contents in the membrane. The combined analysis of neutron spin echo and dynamic light scattering data allows calculation of the bending elastic constant, kappa, of the vesicle bilayer. A stiffening effect monitored as an increase of kappa with increasing cholesterol molar ratio is demonstrated by these measurements.
Group of Biological Membranes and Biorheology, Universidad Complutense, Madrid, Spain.
Laura R
LR
Arriaga
Iván
I
López-Montero
Francisco
F
Monroy
Guillermo
G
Orts-Gil
Bela
B
Farago
Thomas
T
Hellweg
D000465:Algorithms; D002784:Cholesterol / Q000378:metabolism*; D004548:Elasticity; D008027:Light; D008560:Membrane Fluidity / Q000502:physiology*; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D012542:Scattering, Radiation; D013816:Thermodynamics; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism*
D010713:Phosphatidylcholines; D053835:Unilamellar Liposomes; D002784:Cholesterol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine