The orientation behavior of Bombolitin II (BLT2) in the dipalmitoylphosphatidylcholine membrane bilayer was investigated by using molecular-dynamics simulation. During the 20-ns simulation, the BLT2 began to tilt and finally reached the angle of 51° from the membrane-normal. The structure of the peptide formed the amphipathic α-helical structure during the entire simulation time. The peptide tilts with its hydrophobic side faced to the hydrophobic core of the bilayer. We analyzed the mechanism of the tilting behavior of the peptide associated with the membrane in detail. The analysis showed that the hydrogen-bond interaction and the electrostatic interaction were found to exist between Lys(12) and a lipid molecule. These interactions are considered to work as an important factor in tilting the peptide to the membrane-normal.
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http://dx.doi.org/10.1016/j.bpj.2011.07.018 | DOI Listing |
J Biol Inorg Chem
January 2025
Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA.
Lipid nanoparticles formed with copolymers are a new and increasingly powerful tool for studying membrane proteins, but the extent to which these systems affect the physical properties of the membrane is not completely understood. This is critical to understanding the caveats of these new systems and screening for structural and functional artifacts that might be caused in the membrane proteins they are used to study. To better understand these potential effects, the fluid properties of dipalmitoylphosphatidylcholine lipid bilayers were examined by electron paramagnetic resonance (EPR) spectroscopy with spin-labeled reporter lipids in either liposomes or incorporated into nanoparticles with the copolymers diisobutylene-maleic acid or styrene maleic acid.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russia.
Plasma membranes are known to segregate into liquid disordered and ordered nanoscale phases, the latter being called lipid rafts. The structure, lipid composition, and function of lipid rafts have been the subject of numerous studies using a variety of experimental and computational methods. Double electron-electron resonance (DEER, also known as PELDOR) is a member of the pulsed dipole EPR spectroscopy (PDS) family of techniques, allowing the study of nanoscale distances between spin-labeled molecules.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37916, United States.
Eukaryotic plasma membranes exhibit nanoscale lateral lipid heterogeneity, a feature that is thought to be central to their function. Studying these heterogeneities is challenging since few biophysical methods are capable of detecting domains at submicron length scales. We recently showed that cryogenic electron microscopy (cryo-EM) can directly image nanoscale liquid-liquid phase separation in extruded liposomes due to its ability to resolve the intrinsic thickness and electron density differences of ordered and disordered phases.
View Article and Find Full Text PDFLangmuir
January 2025
Departamento de Química, Catedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba 5000, Argentina.
The present work focuses on one of the possible target mechanisms of action of the anionic antimicrobial peptide β-lg derived from trypsin hydrolysis of β-lactoglobulin. After confirmation of bactericidal activity against a pathogenic Gram(+) strain and demonstration of the innocuousness on a eukaryotic cell line, we investigated the interaction of β-lg with monolayers and bilayers of dpPC and dpPC:dpPG as model membranes of eukaryotic and bacterial membranes, respectively. In monolayers, compared to zwitterionic dpPC, in the negatively charged dpPC-dpPG, β-lg injected into the subphase penetrated up to higher surface pressures and showed greater extents of penetration with increasing concentration in the subphase.
View Article and Find Full Text PDFJ Mol Graph Model
March 2025
Department of Chemistry, Faculty of Science and Technology, Muban ChomBueng Rajabhat University, Chom Bueng, Ratchaburi, 70150, Thailand. Electronic address:
Retinol, α-tocopherol and phylloquinone (vitamins A, E, and K) are presented in high concentrations within the chloroplast and leaves of most plants. They are fat-soluble vitamins and absorb similarly to other dietary lipids. Because the molecular mechanism of retinol, α-tocopherol, and phylloquinone absorption is still unknown, this work aims to investigate the distribution of these vitamins at the water/membrane interface using molecular dynamics (MD) simulations.
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