Interpretation of Fluctuation Spectra in Lipid Bilayer Simulations
2011 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 100, no 9, 2104-2111 p.Article in journal (Refereed) Published
Atomic resolution and coarse-grained simulations of dimyristoylphosphatidylcholine lipid bilayers were analyzed for fluctuations perpendicular to the bilayer using a completely Fourier-based method. We find that the fluctuation spectrum of motions perpendicular to the bilayer can be decomposed into just two parts: 1), a pure undulation spectrum proportional to q(-4) that dominates in the small-q regime; and 2), a molecular density structure factor contribution that dominates in the large-q regime. There is no need for a term proportional to q(-2) that has been postulated for protrusion fluctuations and that appeared to have been necessary to fit the spectrum for intermediate q. We suggest that earlier reports of such a term were due to the artifact of binning and smoothing in real space before obtaining the Fourier spectrum. The observability of an intermediate protrusion regime from the fluctuation spectrum is discussed based on measured and calculated material constants.
Place, publisher, year, edition, pages
2011. Vol. 100, no 9, 2104-2111 p.
MOLECULAR-DYNAMICS SIMULATIONS; ENTROPY-DRIVEN TENSION; COARSE-GRAINED MODEL; PARTICLE MESH EWALD; THERMAL FLUCTUATIONS; BENDING ELASTICITY; CONSTANT-PRESSURE; MEMBRANES; HYDRATION; SCATTERING
IdentifiersURN: urn:nbn:se:kth:diva-33982DOI: 10.1016/j.bpj.2011.03.010ISI: 000290360000006ScopusID: 2-s2.0-79959741351OAI: oai:DiVA.org:kth-33982DiVA: diva2:419844
FunderSwedish e‐Science Research Center
QC 201105302011-05-302011-05-232012-05-22Bibliographically approved