Low concentrated hydroxyectoine solutions in presence of DPPC lipid bilayers: a computer simulation study

摘要

The influence of hydroxyectoine on the properties of the aqueous solution inpresence of DPPC lipid bilayers is studied via semi-isotropic constant pressure(NPT) Molecular Dynamics simulations. We investigate the solvent-co-solutebehavior in terms of Kirkwood-Buff integrals as well as hydrogen bond lifetimes for an increasing hydroxyectoine concentration up to 0.148 mol/L. Theobserved preferential exclusion mechanism identifies hydroxyectoine as akosmotropic osmolyte. Our findings in regards to the DPPC lipid bilayerindicate an increase of the surface pressure as well as the solvent accessiblesurface area in presence of higher hydroxyectoine concentrations. The resultsare in agreement to the outcome of recent experiments. With this study, we areable to validate the visibility of co-solute-solute-solvent effects for low andphysiologically relevant osmolyte concentrations.