Analysis of simulated NMR order parameters for lipid bilayer structure determination.

Biophys J

Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.

Published: May 1999

The conventional formula for relating CD2 average order parameters to average methylenic travel is flawed when compared to molecular dynamics simulations of dipalmitoylphosphatidylcholine. Inspired by the simulated probability distribution functions, a new formula is derived that satisfactorily relates these quantities. This formula is used to obtain the average chain length , and the result agrees with the direct simulation result for . The simulation also yields a hydrocarbon thickness 2. The result = is consistent with a model of chain packing with both early chain termination and partial interdigitation of chains from opposing monolayers. The actual simulated area per lipid is easily obtained from the order parameters. However, when this method is applied to NMR order parameter data from dimyristoylphosphatidylcholine, the resulting is 10% larger than the currently accepted value.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1300220PMC
http://dx.doi.org/10.1016/S0006-3495(99)77403-5DOI Listing

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