Abstract
A continuum-level model for a giant unilamellar vesicle (GUV) is bridged to a corresponding atomistic model of a dimyristoylphosphatidylcholine (DMPC) bilayer at various cholesterol concentrations via computation of the bulk modulus. The bulk modulus and other microscopically determined parameters are passed to a continuum-level model operating in time- and length-scales orders of magnitude beyond that which is accessible by atomistic-level simulation. The continuum-level simulation method used is the material point method (MPM), and the particular variation used here takes advantage of the spherical nature of many GUVs. An osmotic pressure gradient due to a solvent concentration change is incorporated into the continuum-level simulation, resulting in osmotic swelling of the vesicle. The model is then extended to treat mixtures of DMPC and cholesterol, where small domains of different composition are considered.
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- Ayton Gary, Smondyrev Alexander M., Bardenhagen Scott G., McMurtry Patrick, Voth Gregory A. Calculating the bulk modulus for a lipid bilayer with nonequilibrium molecular dynamics simulation. Biophys J. 2002 Mar;82(3):1226–1238. doi: 10.1016/S0006-3495(02)75479-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bagatolli L. A., Gratton E. A correlation between lipid domain shape and binary phospholipid mixture composition in free standing bilayers: A two-photon fluorescence microscopy study. Biophys J. 2000 Jul;79(1):434–447. doi: 10.1016/S0006-3495(00)76305-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bagatolli L. A., Gratton E. Two photon fluorescence microscopy of coexisting lipid domains in giant unilamellar vesicles of binary phospholipid mixtures. Biophys J. 2000 Jan;78(1):290–305. doi: 10.1016/S0006-3495(00)76592-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bagatolli L. A., Gratton E. Two-photon fluorescence microscopy observation of shape changes at the phase transition in phospholipid giant unilamellar vesicles. Biophys J. 1999 Oct;77(4):2090–2101. doi: 10.1016/S0006-3495(99)77050-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bagatolli L. A., Parasassi T., Gratton E. Giant phospholipid vesicles: comparison among the whole lipid sample characteristics using different preparation methods: a two photon fluorescence microscopy study. Chem Phys Lipids. 2000 Apr;105(2):135–147. doi: 10.1016/s0009-3084(00)00118-3. [DOI] [PubMed] [Google Scholar]
- Dietrich C., Bagatolli L. A., Volovyk Z. N., Thompson N. L., Levi M., Jacobson K., Gratton E. Lipid rafts reconstituted in model membranes. Biophys J. 2001 Mar;80(3):1417–1428. doi: 10.1016/S0006-3495(01)76114-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gheber L. A., Edidin M. A model for membrane patchiness: lateral diffusion in the presence of barriers and vesicle traffic. Biophys J. 1999 Dec;77(6):3163–3175. doi: 10.1016/S0006-3495(99)77147-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hallett F. R., Marsh J., Nickel B. G., Wood J. M. Mechanical properties of vesicles. II. A model for osmotic swelling and lysis. Biophys J. 1993 Feb;64(2):435–442. doi: 10.1016/S0006-3495(93)81384-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hoover WG. Canonical dynamics: Equilibrium phase-space distributions. Phys Rev A Gen Phys. 1985 Mar;31(3):1695–1697. doi: 10.1103/physreva.31.1695. [DOI] [PubMed] [Google Scholar]
- Kwok R., Evans E. Thermoelasticity of large lecithin bilayer vesicles. Biophys J. 1981 Sep;35(3):637–652. doi: 10.1016/S0006-3495(81)84817-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagle J. F., Wiener M. C. Structure of fully hydrated bilayer dispersions. Biochim Biophys Acta. 1988 Jul 7;942(1):1–10. doi: 10.1016/0005-2736(88)90268-4. [DOI] [PubMed] [Google Scholar]
- Nielsen M., Miao L., Ipsen J. H., Zuckermann M. J., Mouritsen O. G. Off-lattice model for the phase behavior of lipid-cholesterol bilayers. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 May;59(5 Pt B):5790–5803. doi: 10.1103/physreve.59.5790. [DOI] [PubMed] [Google Scholar]
- Olbrich K., Rawicz W., Needham D., Evans E. Water permeability and mechanical strength of polyunsaturated lipid bilayers. Biophys J. 2000 Jul;79(1):321–327. doi: 10.1016/S0006-3495(00)76294-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Rawicz W., Olbrich K. C., McIntosh T., Needham D., Evans E. Effect of chain length and unsaturation on elasticity of lipid bilayers. Biophys J. 2000 Jul;79(1):328–339. doi: 10.1016/S0006-3495(00)76295-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Sagui C., Darden T. A. Molecular dynamics simulations of biomolecules: long-range electrostatic effects. Annu Rev Biophys Biomol Struct. 1999;28:155–179. doi: 10.1146/annurev.biophys.28.1.155. [DOI] [PubMed] [Google Scholar]
- 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]
- Smondyrev A. M., Berkowitz M. L. Molecular dynamics simulation of the structure of dimyristoylphosphatidylcholine bilayers with cholesterol, ergosterol, and lanosterol. Biophys J. 2001 Apr;80(4):1649–1658. doi: 10.1016/S0006-3495(01)76137-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- 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]