Nanodiscs, phospholipid bilayer assemblies of controlled size, were used to self-assemble bacteriorhodopsin (bR) into single trimers. Self-assembly at optimal bR to Nanodisc and phospholipid stoichiometry yielded particles containing three bR molecules. Analysis of solution small angle X-ray scattering indicated that bacteriorhodopsin is embedded in a discoidal phospholipid bilayer structure. Formation of trimers, as evidenced by visible circular dichroism of the retinal absorbance bands, is facilitated in Nanodiscs at a specific size threshold, suggesting that a critical bilayer area or amount of lipid is necessary to maintain a native oligomeric state. The lipid to bR ratio in the assembly process was also found to be an important factor in determining oligomerization state. These nanoscale bilayers offer the opportunity to understand and control the assembly of oligomeric integral membrane proteins critical to macromolecular recognition and cellular signaling.
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http://dx.doi.org/10.1016/j.abb.2006.03.013 | DOI Listing |
Biophys Rev
December 2024
Laboratorio de BioNanotecnología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina.
Synthetic lipids have been studied as components in membrane models and drug delivery systems. Polymerizable phospholipids, especially photosensitive ones, can form new bilayer bonds when UV light irradiates. These phospholipids have been known since the 1980s, but in the last few years, new applications have been highlighted.
View Article and Find Full Text PDFα-Synuclein (αSyn), an intrinsically disordered protein implicated in Parkinson's disease, is potentially thought to initiate aggregation through binding to cellular membranes. Previous studies have suggested that anionic membrane charge is necessary for this binding. However, these studies largely focus on unmodified αSyn, while nearly all αSyn in the body is N-terminally acetylated (NTA).
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States.
Modification of silica interfaces by covalent attachment of functional ligands is a primary means of controlling the interfacial chemistry of porous silicas used in separations, environmental cleanup, and biosensing. Recently, modification of hydrophobic, -alkyl-silane-functionalized interfaces has been achieved through self-assembly of zwitterionic phospholipids or mixed-charged surfactants to form "hybrid bilayers", producing interfaces that mimic lipid-bilayer partitioning and provide shape-selective partitioning of aromatic hydrocarbons. Charged headgroups, however, introduce electrostatic interactions that strongly influence the retention of ionizable solutes and require careful control over pH and ionic strength in the solution phase.
View Article and Find Full Text PDFNeuron
January 2025
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA. Electronic address:
Neurexin cell-adhesion molecules regulate synapse development and function by recruiting synaptic components. Here, we uncover a mechanism for presynaptic assembly that precedes neurexin recruitment, mediated by interactions between cytosolic proteins and membrane phospholipids. Developmental imaging in C.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States.
In this work, we describe a computational tool designed to determine the local dielectric constants (ε) of charge-neutral heterogeneous systems by analyzing dipole moment fluctuations from molecular dynamics (MD) trajectories. Unlike conventional methods, our tool can calculate dielectric constants for dynamically evolving selections of molecules within a defined region of space, rather than for fixed sets of molecules. We validated our approach by computing the dielectric constants of TIP3P water nanospheres, achieving results consistent with literature values for bulk water.
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