Ghysels, An

Hummer, G

Pastor, RW

Venable, RM

English

Ghent University Academic Bibliography

 COMP Emilio Esposito, Scott Wildman Wednesday, April 10, 2013 420 - Oxygen diffusion in water, alkanes, and lipid bilayersAn Ghysels1, an.ghysels@ugent.be, Richard M Venable2, Richard W Pastor2, Gerhard Hummer3. (1) Center for MolecularModeling, Ghent University, Ghent, Belgium, (2) National Heart Lung and Blood Institute, National Institutes of Health, Bethesda,Maryland 20824, United States, (3) National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes ofHealth, Bethesda, Maryland 20824, United StatesOxygen diffusion in the cellular medium and in lipid membranes is essential for aerobic life. We used molecular dynamicssimulations to study the energetics and dynamics of the diffusive O2 transport in water, alkanes and lipid bilayers of differentcomposition. From our simulations the underlying free energy surfaces and diffusion coefficients are determined both inhomogeneous and isotropic neat water and alkane phases, and across inhomogeneous and anisotropic water-alkane interfacesand lipid membranes. Free energy surfaces and position-dependent diffusion tensors describing the oxygen transport within andacross membranes of different lipid compositions are derived from intermediate time propagators analyzed with Bayesianinference. To enter into a lipid bilayer, oxygen needs to overcome a free energy barrier as it passes the head group region.Once inside the membrane, oxygen concentrates at the center, between the two leaflets, where also the local diffusivity isenhanced. Differences in the energetics and diffusivities between the various systems studied point to the underlying molecularmechanisms. The oxygen affinities and in-plane diffusivities are compared for a membrane with a lipid composition mimickingthe inner mitochondrial membrane and for a POPC model membrane. This comparison sheds light on how aerobic life achievesan efficient oxygen delivery to cytochrome c oxidase, the terminal oxidase in mitochondria that drives cellular respiration.Wednesday, April 10, 2013 02:30 PMMembranes (01:30 PM - 04:45 PM)Location: Morial Convention CenterRoom: 356 *ACS does not own copyrights to the individual abstracts. For permission, please contact the author(s) of the abstract. Close Window

Oxygen diffusion water, alkanes, and lipid bilayers

https://biblio.ugent.be/publication/4377208/file/4377243.pdf

Oxygen diffusion water, alkanes, and lipid bilayers

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Ghent University Academic Bibliography