Publications by authors named "Bishoy Khairalla"

Gram-negative bacteria possess a complex structural cell envelope that constitutes a barrier for antimicrobial peptides that neutralize the microbes by disrupting their cell membranes. Computational and experimental approaches were used to study a model outer membrane interaction with an antimicrobial peptide, melittin. The investigated membrane included di[3-deoxy-d-manno-octulosonyl]-lipid A (KLA) in the outer leaflet and 1-palmitoyl-2-oleoyl--glycero-3-phosphoethanolamine (POPE) in the inner leaflet.

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The structural complexity of the cell envelope of Gram-negative bacteria limits the fabrication of realistic models of bacterial cell membranes. A vertical Langmuir-Blodgett withdrawing was used to deposit a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) monolayer on the Au(111) surface. The second leaflet composed of di[3-deoxy-D-manno-octulosonyl]-lipid A (KLA) was deposited using Langmuir-Schaefer transfer.

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The cell membrane of Gram-negative bacteria interacting with an antimicrobial peptide presents a complex supramolecular assembly. Fabrication of models of bacterial cell membranes remains a large experimental challenge. Langmuir-Blodgett and Langmuir-Schaefer (LS-LB) transfer makes possible the deposition of multicomponent asymmetric lipid bilayers onto a gold surface.

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Article Synopsis
  • Planar asymmetric lipid bilayers made from two types of lipids (phosphatidylethanolamine and phosphatidylglycerol) were studied on a gold electrode surface.
  • Research utilized techniques like electrochemically controlled infrared spectroscopy and quartz crystal microbalance to observe structural changes in the bilayers due to electric potentials.
  • The study found that the packing parameter of lipids influences their structural responses to electric fields, with specifics on hydrocarbon chain orientation and hydration, offering insights for biomimetic applications and understanding cell membrane processes.
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