Molecular Dynamics Simulations as a Tool for Accurate Determination of Surfactant Micelle Properties

Molecular dynamics (MD) simulations were used to characterize the equilibrium size, shape, hydration, and self-assembly of dodecylphosphocholine (DPC) and dodecyl-β-D-maltoside (DDM) micelles. We show that DPC molecules self-assemble to form micelles with sizes within the range reported in the experimental literature. The equilibrium shape of DPC and DDM micelles as well as associated micellar radii are in agreement with small-angle X-ray scattering (SAXS) experiments and theoretical packing parameters. In addition, we show that hydration of the micelle interior is limited; however, flexibility of the acyl chains leads to dynamic encounters with the solvated outer shell of the micelle, providing an explanation for long-standing differences in models of micelle hydration. Altogether, our results provide fundamental understanding of physical characteristics of micelles that can be utilized to study other types of detergents and proteomicelle complexes.