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Physical Sciences and Mathematics Commons

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Selected Works

2014

Physics

Molecular Dynamics Simulation

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Structure And Elasticity Of Lipid Membranes With Genistein And Daidzein Bioflavinoids Using X-Ray Scattering And Md Simulations., Mohit Raghunathan, Yuriy Zubovski, Richard Venable, Richard Pastor, John Nagle, Stephanie Tristram-Nagle Aug 2014

Structure And Elasticity Of Lipid Membranes With Genistein And Daidzein Bioflavinoids Using X-Ray Scattering And Md Simulations., Mohit Raghunathan, Yuriy Zubovski, Richard Venable, Richard Pastor, John Nagle, Stephanie Tristram-Nagle

Prof. Stephanie Tristram-Nagle Ph.D.

This work reports the effects of the bioflavinoids genistein and daidzein on lipid bilayers as determined by volume measurements, X-ray scattering, and molecular dynamics simulations. The experimental and simulated total molecular volumes were found to be in outstanding agreement with each other before the addition of genistein and daidzein and also after their addition. Both bioflavinoids inserted into the hydrocarbon region of both DOPC and diphytanoylPC near the carbonyls of the lipids and both decreased the bilayer thicknesses. The long axes of both bioflavinoids were oriented nearly parallel to the plane of the bilayer with their carbonyl groups preferentially pointed …


Alamethicin Aggregation In Lipid Membranes., Jianjun Pan, Stephanie Tristram-Nagle, John Nagle Aug 2014

Alamethicin Aggregation In Lipid Membranes., Jianjun Pan, Stephanie Tristram-Nagle, John Nagle

Prof. Stephanie Tristram-Nagle Ph.D.

X-ray scattering features induced by aggregates of alamethicin (Alm) were obtained in oriented stacks of model membranes of DOPC(diC18:1PC) and diC22:1PC. The first feature obtained near full hydration was Bragg rod in-plane scattering near 0.11 A(-1) in DOPC and near 0.08 A(-1) in diC22:1PC at a 1:10 Alm:lipid ratio. This feature is interpreted as bundles consisting of n Alm monomers in a barrel-stave configuration surrounding a water pore. Fitting the scattering data to previously published molecular dynamics simulations indicates that the number of peptides per bundle is n = 6 in DOPC and n >or= 9 in diC22:1PC. The larger …


Α-Synuclein Induces Both Positive Mean Curvature And Negative Gaussian Curvature In Membranes., Anthony Braun, Eva Sevcsik, Pamela Chin, Elizabeth Rhoades, Stephanie Tristram-Nagle, Jonathan Sachs Aug 2014

Α-Synuclein Induces Both Positive Mean Curvature And Negative Gaussian Curvature In Membranes., Anthony Braun, Eva Sevcsik, Pamela Chin, Elizabeth Rhoades, Stephanie Tristram-Nagle, Jonathan Sachs

Prof. Stephanie Tristram-Nagle Ph.D.

Using a combination of X-ray scattering, fluorescence correlation spectroscopy, coarse-grained molecular dynamics (MD) simulations and potential of mean force calculations, we have explored the membrane remodeling effects of monomeric α-synuclein (αS). Our initial findings from multiple approaches are that αS (1) causes a significant thinning of the bilayer and (2) stabilizes positive mean curvature, such that the maximum principle curvature matches that of synaptic vesicles, αS-induced tubules, and the synthetic lipid vesicles to which the protein binds most tightly. This suggests that αS binding to synaptic vesicles likely stabilizes their intrinsic curvature. We then show that αS induces local negative …