Bending rigidity of SOPC membranes containing cholesterol

Biophys J. 1993 Jun;64(6):1967-70. doi: 10.1016/S0006-3495(93)81566-2.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cholesterol*
  • Lipid Bilayers*
  • Mathematics
  • Models, Theoretical
  • Molecular Conformation
  • Phosphatidylcholines / chemistry*
  • Pressure


  • Lipid Bilayers
  • Phosphatidylcholines
  • 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine
  • Cholesterol