Cholesterol versus alpha-tocopherol: effects on properties of bilayers made from heteroacid phosphatidylcholines

Biochemistry. 1996 Oct 15;35(41):13353-62. doi: 10.1021/bi961058m.


The techniques of differential scanning calorimetry, fluorescence of merocyanine 540, fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene, proton permeability, and lipid peroxidation are used to compare the perturbations of cholesterol and alpha-tocopherol on lipid bilayer membranes composed of different phosphatidylcholines containing stearic acid in the sn-1 position and an unsaturated fatty acid (either oleic, alpha-linolenic, gamma-linolenic, or docosahexaenoic acid) in the sn-2 position. It is concluded that the structural roles of cholesterol and alpha-tocopherol may be similar with membranes composed of some phosphatidylcholines but are clearly different with membranes composed of other related phosphatidylcholines. alpha-Tocopherol exerts a much larger effect than cholesterol on membranes rich in polyunsaturated fatty acids that have their initial double bond before the delta 9 position. Cholesterol interacts more favorably with fatty acids that do not have an double bond before the delta 9 position. The membrane structural effects are explained in terms of the larger size of the sterol ring structure of cholesterol compared to the smaller chromanol ring of the alpha-tocopherol.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calorimetry, Differential Scanning
  • Cholesterol / chemistry*
  • Diphenylhexatriene
  • Docosahexaenoic Acids / chemistry
  • Fluorescence Polarization
  • Fluorescent Dyes
  • Lipid Bilayers / chemistry*
  • Lipid Peroxidation
  • Macromolecular Substances
  • Molecular Structure
  • Oleic Acid / chemistry
  • Permeability
  • Phosphatidylcholines / chemistry*
  • Protons
  • Pyrimidinones
  • Spectrometry, Fluorescence
  • Thermodynamics
  • Vitamin E / chemistry*


  • Fluorescent Dyes
  • Lipid Bilayers
  • Macromolecular Substances
  • Phosphatidylcholines
  • Protons
  • Pyrimidinones
  • Vitamin E
  • Diphenylhexatriene
  • Docosahexaenoic Acids
  • Oleic Acid
  • merocyanine dye
  • Cholesterol