Bending rigidity of SOPC membranes containing cholesterol.
Bilayer membranes in the fluid state exhibit a large resistance to changes in surface area, negligible resistance to surface shear deformation, and a small but finite resistance to bending. The presence of cholesterol in the membrane is known to increase its resistance to area dilation. In this report, a new method for measuring bilayer membrane bending stiffness has been used to investigate the effect of cholesterol on the bending rigidity of SOPC (1,stearoyl-2,oleoyl-phosphatidylcholine) membranes. The curvature elasticity (kc) for membranes saturated with cholesterol was measured to be 3.3 x 10(-19) J, approximately 3-fold larger than that the modulus for cholesterol-free SOPC membrane. These findings are consistent with previous measurements of bending stiffness based on thermal fluctuations, which showed a similar approximately 3-fold increase in the modulus with cholesterol addition (Evans and Rawicz, 1990, Phys. Rev. Lett. 64:2094) and provide further substantiation of the important contribution that cholesterol makes to membrane cohesion and stability.
Song
J
J
Department of Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642.
Waugh
R E
RE
D002784:Cholesterol; D008051:Lipid Bilayers; D008433:Mathematics; D008962:Models, Theoretical; D008968:Molecular Conformation; D010713:Phosphatidylcholines / Q000737:chemistry*; D011312:Pressure
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; C027891:1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine; D002784:Cholesterol