Stachura S. and Kneller G.R.
Molecular Simulation (2014) 40 (1-3) 245-250 - doi : 10.1080/08927022.2013.840902
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In the present article we study the lateral molecular di-usion in homogenous lipid (POPC) bilayers by molecular dynamics simulations with the all-atom OPLS and the coarse-grained MARTINI force fields. On the statistically relevant time scales the center-of-mass mean-square displacement exhibits in both cases the subdiffusive asymptotic form W (t) 2Dαtα , with α ≈ 0.67 and α ≈ 0.57 , respectively. The diffusive dynamics obtained by the MARTINI force field is, however, faster by a factor of about 3. The subdiffusive characteristics of the di-usion process is confirmed by comparing the integral of the center-of-mass velocity autocorrelation function with its analytical long-time tail. The agreement is particularly good for the MARTINI force field, which permits to extend the simulation length and the system size considerably. Our results are in agreement with experimental observations of subdi-usion in lipid bilayers on longer time scales and do not support the finding of some authors that the latter should be considered as a transient phenomenon.