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Biophys J. Jul 2000; 79(1): 328–339.
PMCID: PMC1300937

Effect of chain length and unsaturation on elasticity of lipid bilayers.

Abstract

Micropipette pressurization of giant bilayer vesicles was used to measure both elastic bending k(c) and area stretch K(A) moduli of fluid-phase phosphatidylcholine (PC) membranes. Twelve diacyl PCs were chosen: eight with two 18 carbon chains and degrees of unsaturation from one double bond (C18:1/0, C18:0/1) to six double bonds per lipid (diC18:3), two with short saturated carbon chains (diC13:0, diC14:0), and two with long unsaturated carbon chains (diC20:4, diC22:1). Bending moduli were derived from measurements of apparent expansion in vesicle surface area under very low tensions (0.001-0.5 mN/m), which is dominated by smoothing of thermal bending undulations. Area stretch moduli were obtained from measurements of vesicle surface expansion under high tensions (>0.5 mN/m), which involve an increase in area per molecule and a small-but important-contribution from smoothing of residual thermal undulations. The direct stretch moduli varied little (< +/-10%) with either chain unsaturation or length about a mean of 243 mN/m. On the other hand, the bending moduli of saturated/monounsaturated chain PCs increased progressively with chain length from 0.56 x 10(-19) J for diC13:0 to 1.2 x 10(-19) J for diC22:1. However, quite unexpectedly for longer chains, the bending moduli dropped precipitously to approximately 0.4 x 10(-19) J when two or more cis double bonds were present in a chain (C18:0/2, diC18:2, diC18:3, diC20:4). Given nearly constant area stretch moduli, the variations in bending rigidity with chain length and polyunsaturation implied significant variations in thickness. To test this hypothesis, peak-to-peak headgroup thicknesses h(pp) of bilayers were obtained from x-ray diffraction of multibilayer arrays at controlled relative humidities. For saturated/monounsaturated chain bilayers, the distances h(pp) increased smoothly from diC13:0 to diC22:1 as expected. Moreover, the distances and elastic properties correlated well with a polymer brush model of the bilayer that specifies that the elastic ratio (k(c)/K(A))(1/2) = (h(pp) - h(o))/24, where h(o) approximately 1 nm accounts for separation of the headgroup peaks from the deformable hydrocarbon region. However, the elastic ratios and thicknesses for diC18:2, diC18:3, and diC20:4 fell into a distinct group below the correlation, which showed that poly-cis unsaturated chain bilayers are thinner and more flexible than saturated/monounsaturated chain bilayers.

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Selected References

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  • Applegate KR, Glomset JA. Effect of acyl chain unsaturation on the conformation of model diacylglycerols: a computer modeling study. J Lipid Res. 1991 Oct;32(10):1635–1644. [PubMed]
  • Blaurock AE, Worthington CR. Treatment of low angle x-ray data from planar and concentric multilayered structures. Biophys J. 1966 May;6(3):305–312. [PMC free article] [PubMed]
  • Bo L, Waugh RE. Determination of bilayer membrane bending stiffness by tether formation from giant, thin-walled vesicles. Biophys J. 1989 Mar;55(3):509–517. [PMC free article] [PubMed]
  • Cantor RS. Lipid composition and the lateral pressure profile in bilayers. Biophys J. 1999 May;76(5):2625–2639. [PMC free article] [PubMed]
  • Evans E, Bowman H, Leung A, Needham D, Tirrell D. Biomembrane templates for nanoscale conduits and networks. Science. 1996 Aug 16;273(5277):933–935. [PubMed]
  • Evans E, Rawicz W. Entropy-driven tension and bending elasticity in condensed-fluid membranes. Phys Rev Lett. 1990 Apr 23;64(17):2094–2097. [PubMed]
  • Hallett FR, Marsh J, Nickel BG, Wood JM. Mechanical properties of vesicles. II. A model for osmotic swelling and lysis. Biophys J. 1993 Feb;64(2):435–442. [PMC free article] [PubMed]
  • Herbette L, Marquardt J, Scarpa A, Blasie JK. A direct analysis of lamellar x-ray diffraction from hydrated oriented multilayers of fully functional sarcoplasmic reticulum. Biophys J. 1977 Nov;20(2):245–272. [PMC free article] [PubMed]
  • Hitchcock PB, Mason R, Thomas KM, Shipley GG. Structural chemistry of 1,2 dilauroyl-DL-phosphatidylethanolamine: molecular conformation and intermolecular packing of phospholipids. Proc Natl Acad Sci U S A. 1974 Aug;71(8):3036–3040. [PMC free article] [PubMed]
  • Kim RS, LaBella FS. Comparison of analytical methods for monitoring autoxidation profiles of authentic lipids. J Lipid Res. 1987 Sep;28(9):1110–1117. [PubMed]
  • Koenig BW, Strey HH, Gawrisch K. Membrane lateral compressibility determined by NMR and x-ray diffraction: effect of acyl chain polyunsaturation. Biophys J. 1997 Oct;73(4):1954–1966. [PMC free article] [PubMed]
  • Kwok R, Evans E. Thermoelasticity of large lecithin bilayer vesicles. Biophys J. 1981 Sep;35(3):637–652. [PMC free article] [PubMed]
  • McIntosh TJ, Advani S, Burton RE, Zhelev DV, Needham D, Simon SA. Experimental tests for protrusion and undulation pressures in phospholipid bilayers. Biochemistry. 1995 Jul 11;34(27):8520–8532. [PubMed]
  • McIntosh TJ, Holloway PW. Determination of the depth of bromine atoms in bilayers formed from bromolipid probes. Biochemistry. 1987 Mar 24;26(6):1783–1788. [PubMed]
  • McIntosh TJ, Magid AD, Simon SA. Steric repulsion between phosphatidylcholine bilayers. Biochemistry. 1987 Nov 17;26(23):7325–7332. [PubMed]
  • McIntosh TJ, Magid AD, Simon SA. Cholesterol modifies the short-range repulsive interactions between phosphatidylcholine membranes. Biochemistry. 1989 Jan 10;28(1):17–25. [PubMed]
  • McIntosh TJ, Simon SA. Hydration force and bilayer deformation: a reevaluation. Biochemistry. 1986 Jul 15;25(14):4058–4066. [PubMed]
  • McIntosh TJ, Simon SA. Area per molecule and distribution of water in fully hydrated dilauroylphosphatidylethanolamine bilayers. Biochemistry. 1986 Aug 26;25(17):4948–4952. [PubMed]
  • McIntosh TJ, Simon SA, Needham D, Huang CH. Structure and cohesive properties of sphingomyelin/cholesterol bilayers. Biochemistry. 1992 Feb 25;31(7):2012–2020. [PubMed]
  • Mui BL, Cullis PR, Evans EA, Madden TD. Osmotic properties of large unilamellar vesicles prepared by extrusion. Biophys J. 1993 Feb;64(2):443–453. [PMC free article] [PubMed]
  • Needham D, McIntosh TJ, Evans E. Thermomechanical and transition properties of dimyristoylphosphatidylcholine/cholesterol bilayers. Biochemistry. 1988 Jun 28;27(13):4668–4673. [PubMed]
  • Petrache HI, Tristram-Nagle S, Nagle JF. Fluid phase structure of EPC and DMPC bilayers. Chem Phys Lipids. 1998 Sep;95(1):83–94. [PMC free article] [PubMed]
  • Rabinovich AL, Ripatti PO. On the conformational, physical properties and functions of polyunsaturated acyl chains. Biochim Biophys Acta. 1991 Aug 20;1085(1):53–62. [PubMed]
  • Rutkowski CA, Williams LM, Haines TH, Cummins HZ. The elasticity of synthetic phospholipid vesicles obtained by photon correlation spectroscopy. Biochemistry. 1991 Jun 11;30(23):5688–5696. [PubMed]
  • Smaby JM, Muderhwa JM, Brockman HL. Is lateral phase separation required for fatty acid to stimulate lipases in a phosphatidylcholine interface? Biochemistry. 1994 Feb 22;33(7):1915–1922. [PubMed]
  • Tristram-Nagle S, Petrache HI, Nagle JF. Structure and interactions of fully hydrated dioleoylphosphatidylcholine bilayers. Biophys J. 1998 Aug;75(2):917–925. [PMC free article] [PubMed]

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