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Lipid membranes with transmembrane proteins in shear flow

Khoshnood, A ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1063/1.3285269
  3. Abstract:
  4. The effects of embedded proteins on the dynamical properties of lipid bilayer membranes are studied in shear flow. Coarse-grained molecular simulations are employed, in which lipids are modeled as short polymers consisting of hydrophilic head groups and hydrophobic tail monomers; similarly, transmembrane proteins are modeled as connected hydrophobic double- or triple-chain molecules with hydrophilic groups at both ends. In thermal equilibrium, rigid proteinlike molecules aggregate in a membrane of flexible lipids, while flexible proteins do not aggregate. In shear flow parallel to the membrane, the monolayers of lipid bilayer slide over each other. The presence of transmembrane proteins enhances the intermonolayer friction. The friction coefficient depends on the chain lengths of lipids, the membrane tension, the length of the protein, and the cluster size. It is found to increase with protein length (with positive mismatch, i.e., proteins which are longer than the membrane thickness) and protein cluster size. In flow, proteins get oriented in the flow direction to reduce friction, with large fluctuations of the orientation angle
  5. Keywords:
  6. Chain molecules ; Cluster sizes ; Coarse-grained ; Dynamical properties ; Flow direction ; Friction coefficients ; Hydrophilic groups ; Hydrophilic heads ; Hydrophobic tails ; Intermonolayer friction ; Lipid bilayer membranes ; Lipid membranes ; Membrane tension ; Membrane thickness ; Molecular simulations ; Orientation angles ; Protein clusters ; Protein length ; Thermal equilibriums ; Trans-membrane proteins ; Hydrophilicity ; Hydrophobicity ; Lipid bilayers ; Lipids ; Membranes ; Monolayers ; Parallel flow ; Shear flow ; Tribology ; Proteins ; Membrane lipid ; Membrane protein ; Article ; Chemical structure ; Chemistry ; Computer simulation ; Friction ; Membrane lipids ; Membrane proteins ; Models, molecular
  7. Source: Journal of Chemical Physics ; Volume 132, Issue 2 , 2010 ; 00219606 (ISSN)
  8. URL: http://aip.scitation.org/doi/abs/10.1063/1.3285269?journalCode=jcp