Bending and Gaussian moduli of a homogenious single-component lipid bilayer are calculated analytically using microscopic model of the lipid hydrocarbon chains. The approach allows for thermodynamic averaging over different chains conformations. Each chain is modeled as a flexible string with finite bending rigidity and an incompressible cross-section area. The interchain steric repulsion is accounted for self-consistently determined single-chain confining parabolic potential. The model provides a simple analytical expression for the membrane bending modulus, which falls within a range of experimental values. An observed dependence of the modulus on hydrocarbon chain length is also reproduced. Correspondence between our microscopic model and the membrane theory of elasticity is established.
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http://dx.doi.org/10.1103/PhysRevE.94.042415 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
The onset and development of Alzheimer's disease is linked to the accumulation of pathological aggregates formed from the normally monomeric amyloid-β peptide within the central nervous system. These Aβ aggregates are increasingly successfully targeted with clinical therapies at later stages of the disease, but the fundamental molecular steps in early stage disease that trigger the initial nucleation event leading to the conversion of monomeric Aβ peptide into pathological aggregates remain unknown. Here, we show that the Aβ peptide can form biomolecular condensates on lipid bilayers both in molecular assays and in living cells.
View Article and Find Full Text PDFChemMedChem
January 2025
University of Michigan Michigan Medicine, Internal Medicine, 2800 Plymouth Rd, NCRC 26-220S, 48109, Ann Arbor, UNITED STATES OF AMERICA.
A key molecular dysfunction in heart failure is the reduced activity of the cardiac sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) in cardiac muscle cells. Reactivating SERCA2a improves cardiac function in heart failure models, making it a validated target and an attractive therapeutic approach for heart failure therapy. However, finding small-molecule SERCA2a activators is challenging.
View Article and Find Full Text PDFMicrobiol Mol Biol Rev
January 2025
Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
Vesicular mechanisms of drug resistance are known to exist across prokaryotes and eukaryotes. Vesicles are sacs that form when a lipid bilayer 'bends' to engulf and isolate contents from the cytoplasm or extracellular environment. They have a wide range of functions, including vehicles of communication within and across cells, trafficking of protein intermediates to their rightful organellar destinations, and carriers of substrates destined for autophagy.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom. Electronic address:
Photosynthetic organisms rely on a network of light-harvesting protein-pigment complexes to efficiently absorb sunlight and transfer excitation energy to reaction centre proteins where charge separation occurs. In photosynthetic purple bacteria, these complexes are embedded within the cell membrane, with lipid composition affecting complex clustering, thereby impacting inter-complex energy transfer. However, the impact of the lipid bilayer on intra-complex excitation dynamics is less understood.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Frankfurt Institute for Advanced Studies, Frankfurt am Main 60438, Germany.
The assembly of proteins in membranes plays a key role in many crucial cellular pathways. Despite their importance, characterizing transmembrane assembly remains challenging for experiments and simulations. Equilibrium molecular dynamics simulations do not cover the time scales required to sample the typical transmembrane assembly.
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