Skip to main content
Biophysical Journal logoLink to Biophysical Journal
. 2001 Mar;80(3):1104–1114. doi: 10.1016/S0006-3495(01)76088-2

Combined Monte Carlo and molecular dynamics simulation of hydrated lipid-cholesterol lipid bilayers at low cholesterol concentration.

S W Chiu 1, E Jakobsson 1, H L Scott 1
PMCID: PMC1301307  PMID: 11222276

Abstract

We have applied a hybrid equilibration and sampling procedure for the atomic level simulation of a hydrated lipid bilayer to systems consisting of dipalmitoyl phosphatidylcholine (DPPC) and cholesterol, and palmitoyl-oleyl phosphatidylcholine (POPC) at low (approximately 6%) cholesterol concentration. The procedure is applied to bilayers of 94 molecules of DPPC, 6 molecules of cholesterol, and 3205 water molecules, and to bilayers of 120 molecules of POPC, 8 molecules of cholesterol, and 4268 water molecules, at a temperature of 325 K. After equilibration, three separate 400-ps continuous molecular dynamics runs, separated by 10,000 configurational bias Monte Carlo steps, were carried out for each system. Properties of the systems were calculated and averaged over the three separate runs. Results of the simulations are presented and compared with experimental data and with other recent simulations of DPPC and cholesterol, and of pure DPPC, and pure POPC. Certain properties of the bilayers are indistinguishable from cholesterol-free bilayers, including lateral diffusion and electron density. Other properties, most notably the order parameter profile, show the effect of cholesterol even at low concentrations.

Full Text

The Full Text of this article is available as a PDF (665.1 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Armen R. S., Uitto O. D., Feller S. E. Phospholipid component volumes: determination and application to bilayer structure calculations. Biophys J. 1998 Aug;75(2):734–744. doi: 10.1016/S0006-3495(98)77563-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Berger O., Edholm O., Jähnig F. Molecular dynamics simulations of a fluid bilayer of dipalmitoylphosphatidylcholine at full hydration, constant pressure, and constant temperature. Biophys J. 1997 May;72(5):2002–2013. doi: 10.1016/S0006-3495(97)78845-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brown R. E. Sphingolipid organization in biomembranes: what physical studies of model membranes reveal. J Cell Sci. 1998 Jan;111(Pt 1):1–9. doi: 10.1242/jcs.111.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chiu S. W., Clark M., Balaji V., Subramaniam S., Scott H. L., Jakobsson E. Incorporation of surface tension into molecular dynamics simulation of an interface: a fluid phase lipid bilayer membrane. Biophys J. 1995 Oct;69(4):1230–1245. doi: 10.1016/S0006-3495(95)80005-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chiu S. W., Jakobsson E., Subramaniam S., Scott H. L. Combined Monte Carlo and molecular dynamics simulation of fully hydrated dioleyl and palmitoyl-oleyl phosphatidylcholine lipid bilayers. Biophys J. 1999 Nov;77(5):2462–2469. doi: 10.1016/S0006-3495(99)77082-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Copeland B. R., McConnel H. M. The rippled structure in bilayer membranes of phosphatidylcholine and binary mixtures of phosphatidylcholine and cholesterol. Biochim Biophys Acta. 1980 Jun 20;599(1):95–109. doi: 10.1016/0005-2736(80)90059-0. [DOI] [PubMed] [Google Scholar]
  7. Edholm O., Nyberg A. M. Cholesterol in model membranes. A molecular dynamics simulation. Biophys J. 1992 Oct;63(4):1081–1089. doi: 10.1016/S0006-3495(92)81678-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Egberts E., Marrink S. J., Berendsen H. J. Molecular dynamics simulation of a phospholipid membrane. Eur Biophys J. 1994;22(6):423–436. doi: 10.1007/BF00180163. [DOI] [PubMed] [Google Scholar]
  9. Feller S. E., Yin D., Pastor R. W., MacKerell A. D., Jr Molecular dynamics simulation of unsaturated lipid bilayers at low hydration: parameterization and comparison with diffraction studies. Biophys J. 1997 Nov;73(5):2269–2279. doi: 10.1016/S0006-3495(97)78259-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Gliss C., Randel O., Casalta H., Sackmann E., Zorn R., Bayerl T. Anisotropic motion of cholesterol in oriented DPPC bilayers studied by quasielastic neutron scattering: the liquid-ordered phase. Biophys J. 1999 Jul;77(1):331–340. doi: 10.1016/S0006-3495(99)76893-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hristova K., White S. H. Determination of the hydrocarbon core structure of fluid dioleoylphosphocholine (DOPC) bilayers by x-ray diffraction using specific bromination of the double-bonds: effect of hydration. Biophys J. 1998 May;74(5):2419–2433. doi: 10.1016/S0006-3495(98)77950-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Huang P., Perez J. J., Loew G. H. Molecular dynamics simulations of phospholipid bilayers. J Biomol Struct Dyn. 1994 Apr;11(5):927–956. doi: 10.1080/07391102.1994.10508045. [DOI] [PubMed] [Google Scholar]
  13. Hyslop P. A., Morel B., Sauerheber R. D. Organization and interaction of cholesterol and phosphatidylcholine in model bilayer membranes. Biochemistry. 1990 Jan 30;29(4):1025–1038. doi: 10.1021/bi00456a027. [DOI] [PubMed] [Google Scholar]
  14. Ipsen J. H., Karlström G., Mouritsen O. G., Wennerström H., Zuckermann M. J. Phase equilibria in the phosphatidylcholine-cholesterol system. Biochim Biophys Acta. 1987 Nov 27;905(1):162–172. doi: 10.1016/0005-2736(87)90020-4. [DOI] [PubMed] [Google Scholar]
  15. Jakobsson E. Computer simulation studies of biological membranes: progress, promise and pitfalls. Trends Biochem Sci. 1997 Sep;22(9):339–344. doi: 10.1016/s0968-0004(97)01096-7. [DOI] [PubMed] [Google Scholar]
  16. Lafleur M., Cullis P. R., Bloom M. Modulation of the orientational order profile of the lipid acyl chain in the L alpha phase. Eur Biophys J. 1990;19(2):55–62. doi: 10.1007/BF00185086. [DOI] [PubMed] [Google Scholar]
  17. Le Guernevé C., Auger M. New approach to study fast and slow motions in lipid bilayers: application to dimyristoylphosphatidylcholine-cholesterol interactions. Biophys J. 1995 May;68(5):1952–1959. doi: 10.1016/S0006-3495(95)80372-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. McCabe M. A., Griffith G. L., Ehringer W. D., Stillwell W., Wassall S. R. 2H NMR studies of isomeric omega 3 and omega 6 polyunsaturated phospholipid membranes. Biochemistry. 1994 Jun 14;33(23):7203–7210. doi: 10.1021/bi00189a024. [DOI] [PubMed] [Google Scholar]
  19. McMullen T. P., Lewis R. N., McElhaney R. N. Comparative differential scanning calorimetric and FTIR and 31P-NMR spectroscopic studies of the effects of cholesterol and androstenol on the thermotropic phase behavior and organization of phosphatidylcholine bilayers. Biophys J. 1994 Mar;66(3 Pt 1):741–752. doi: 10.1016/s0006-3495(94)80850-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. McMullen T. P., McElhaney R. N. New aspects of the interaction of cholesterol with dipalmitoylphosphatidylcholine bilayers as revealed by high-sensitivity differential scanning calorimetry. Biochim Biophys Acta. 1995 Mar 8;1234(1):90–98. doi: 10.1016/0005-2736(94)00266-r. [DOI] [PubMed] [Google Scholar]
  21. Pasenkiewicz-Gierula M., Róg T., Kitamura K., Kusumi A. Cholesterol effects on the phosphatidylcholine bilayer polar region: a molecular simulation study. Biophys J. 2000 Mar;78(3):1376–1389. doi: 10.1016/S0006-3495(00)76691-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Radhakrishnan A., McConnell H. M. Condensed complexes of cholesterol and phospholipids. Biophys J. 1999 Sep;77(3):1507–1517. doi: 10.1016/S0006-3495(99)76998-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Robinson A. J., Richards W. G., Thomas P. J., Hann M. M. Behavior of cholesterol and its effect on head group and chain conformations in lipid bilayers: a molecular dynamics study. Biophys J. 1995 Jan;68(1):164–170. doi: 10.1016/S0006-3495(95)80171-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sankaram M. B., Thompson T. E. Modulation of phospholipid acyl chain order by cholesterol. A solid-state 2H nuclear magnetic resonance study. Biochemistry. 1990 Nov 27;29(47):10676–10684. doi: 10.1021/bi00499a015. [DOI] [PubMed] [Google Scholar]
  25. Scott H. L. Lipid-cholesterol interactions. Monte Carlo simulations and theory. Biophys J. 1991 Feb;59(2):445–455. doi: 10.1016/S0006-3495(91)82238-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Slotte J. P. Lateral domain heterogeneity in cholesterol/phosphatidylcholine monolayers as a function of cholesterol concentration and phosphatidylcholine acyl chain length. Biochim Biophys Acta. 1995 Sep 13;1238(2):118–126. doi: 10.1016/0005-2736(95)00127-o. [DOI] [PubMed] [Google Scholar]
  27. Smaby J. M., Momsen M. M., Brockman H. L., Brown R. E. Phosphatidylcholine acyl unsaturation modulates the decrease in interfacial elasticity induced by cholesterol. Biophys J. 1997 Sep;73(3):1492–1505. doi: 10.1016/S0006-3495(97)78181-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Smondyrev A. M., Berkowitz M. L. Structure of dipalmitoylphosphatidylcholine/cholesterol bilayer at low and high cholesterol concentrations: molecular dynamics simulation. Biophys J. 1999 Oct;77(4):2075–2089. doi: 10.1016/S0006-3495(99)77049-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Thewalt J. L., Bloom M. Phosphatidylcholine: cholesterol phase diagrams. Biophys J. 1992 Oct;63(4):1176–1181. doi: 10.1016/S0006-3495(92)81681-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Tieleman D. P., Marrink S. J., Berendsen H. J. A computer perspective of membranes: molecular dynamics studies of lipid bilayer systems. Biochim Biophys Acta. 1997 Nov 21;1331(3):235–270. doi: 10.1016/s0304-4157(97)00008-7. [DOI] [PubMed] [Google Scholar]
  31. Tu K., Klein M. L., Tobias D. J. Constant-pressure molecular dynamics investigation of cholesterol effects in a dipalmitoylphosphatidylcholine bilayer. Biophys J. 1998 Nov;75(5):2147–2156. doi: 10.1016/S0006-3495(98)77657-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Tu K., Tobias D. J., Klein M. L. Constant pressure and temperature molecular dynamics simulation of a fully hydrated liquid crystal phase dipalmitoylphosphatidylcholine bilayer. Biophys J. 1995 Dec;69(6):2558–2562. doi: 10.1016/S0006-3495(95)80126-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Urbina J. A., Pekerar S., Le H. B., Patterson J., Montez B., Oldfield E. Molecular order and dynamics of phosphatidylcholine bilayer membranes in the presence of cholesterol, ergosterol and lanosterol: a comparative study using 2H-, 13C- and 31P-NMR spectroscopy. Biochim Biophys Acta. 1995 Sep 13;1238(2):163–176. doi: 10.1016/0005-2736(95)00117-l. [DOI] [PubMed] [Google Scholar]
  34. Venable R. M., Zhang Y., Hardy B. J., Pastor R. W. Molecular dynamics simulations of a lipid bilayer and of hexadecane: an investigation of membrane fluidity. Science. 1993 Oct 8;262(5131):223–226. doi: 10.1126/science.8211140. [DOI] [PubMed] [Google Scholar]
  35. Vist M. R., Davis J. H. Phase equilibria of cholesterol/dipalmitoylphosphatidylcholine mixtures: 2H nuclear magnetic resonance and differential scanning calorimetry. Biochemistry. 1990 Jan 16;29(2):451–464. doi: 10.1021/bi00454a021. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES