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Full-Text Articles in Physics
Scaling And Alpha-Helix Regulation Of Protein Relaxation In A Lipid Bilayer, Liming Qiu, Creighton Buie, Kwan H. Cheng, Mark W. Vaughn
Scaling And Alpha-Helix Regulation Of Protein Relaxation In A Lipid Bilayer, Liming Qiu, Creighton Buie, Kwan H. Cheng, Mark W. Vaughn
Physics and Astronomy Faculty Research
Protein conformation and orientation in the lipid membrane plays a key role in many cellular processes. Here we use molecular dynamics simulation to investigate the relaxation and C-terminus diffusion of a model helical peptide: beta-amyloid (Aβ) in a lipid membrane.We observed that after the helical peptide was initially half-embedded in the extracelluar leaflet of phosphatidylcholine (PC) or PC/cholesterol (PC/CHOL) membrane, the C-terminus diffused across the membrane and anchored to PC headgroups of the cytofacial lipid leaflet. In some cases, the membrane insertion domain of the Aβ was observed to partially unfold. Applying a sigmoidal fit to the process, we found …
Molecular Dynamics Simulations Reveal The Protective Role Of Cholesterol In Β-Amyloid Protein-Induced Membrane Disruptions In Neuronal Membrane Mimics, Liming Qiu, Creighton Buie, Andrew Reay, Mark W. Vaughn, Kwan H. Cheng
Molecular Dynamics Simulations Reveal The Protective Role Of Cholesterol In Β-Amyloid Protein-Induced Membrane Disruptions In Neuronal Membrane Mimics, Liming Qiu, Creighton Buie, Andrew Reay, Mark W. Vaughn, Kwan H. Cheng
Physics and Astronomy Faculty Research
Interactions of β-amyloid (Aβ) peptides with neuronal membranes have been associated with the pathogenesis of Alzheimer's disease (AD); however, the molecular details remain unclear. We used atomistic molecular dynamics (MD) simulations to study the interactions of Aβ40 and Aβ42 with model neuronal membranes. The differences between cholesterol-enriched and depleted lipid domains were investigated by the use of model phosphatidylcholine (PC) lipid bilayers with and without 40 mol % cholesterol. A total of 16 independent 200 ns simulation replicates were investigated. The surface area per lipid, bilayer thickness, water permeability barrier, and lipid order parameter, which are sensitive indicators …