A combination of fluorescence polarization (FPZ) and nuclear magnetic resonance (NMR) techniques have revealed that ethanol has diverse and domain dependent effects on membrane order. Under some conditions, in the more superficial membrane domains, ethanol actually orders rather disorders membrane structure. Using 1H-NMR we have examined in synaptic membranes from LS and SS mice the effects of ethanol-d6 on membrane order. The lines differ most significantly in terms of the ethanol effects on the choline methyl resonances. Ethanol was significantly more potent in increasing choline methyl resonance intensity in LS synaptic membranes than in SS synaptic membranes; these data are interpreted to show a significantly greater disordering of the superficial domains in the LS membranes. The maximum ethanol effect was observed between 0.3% and 0.5% for the concentration range studied (0.1 to 1.0%). The methylene resonance data in general paralleled the choline methyl resonance data but with a somewhat attenuated response. Ethanol had only small effects on the terminal methyl resonance in both lines. Overall, we conclude that the LS and SS mice differ in the ethanol-induced perturbation of membrane structure, primarily at more superficial membrane domains.
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Langmuir
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Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, United States.
Biological memory is the ability to develop, retain, and retrieve information over time. Currently, it is widely accepted that memories are stored in synapses (i.e.
View Article and Find Full Text PDFCurr Neuropharmacol
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Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy.
The central nervous system (CNS) is not an immune-privileged compartment, but it is intimately intertwined with the immune system. Among the components shared by the two compartments is the complement, a main constituent of innate immunity, which is also produced centrally and controls the development and organization of synaptic connections. Complement is considered a doubled-faced system that, besides controlling the physiological development of the central network, also subserves synaptic engulfment pivotal to the progression of neurodegenerative diseases.
View Article and Find Full Text PDFFEBS Open Bio
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Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Germany.
Neurotransmitter release is triggered in microseconds by the two C domains of the Ca sensor synaptotagmin-1 and by SNARE complexes, which form four-helix bundles that bridge the vesicle and plasma membranes. The synaptotagmin-1 CB domain binds to the SNARE complex via a 'primary interface', but the mechanism that couples Ca-sensing to membrane fusion is unknown. Widespread models postulate that the synaptotagmin-1 Ca-binding loops accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers or helping bridge the membranes, but these models do not seem compatible with SNARE binding through the primary interface, which orients the Ca-binding loops away from the fusion site.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA.
Complexins are a family of small presynaptic proteins that regulate neurotransmitter release at nerve terminals and are highly conserved in evolution. While direct interactions with SNARE proteins are critical for all complexin functions, binding of their disordered C-terminal domains (CTD) to membranes, especially to synaptic vesicle membranes, is essential for the ability of complexin to inhibit vesicle release. Furthermore, while some complexin CTDs possess an endogenous affinity for membranes, other complexin isoforms are subject to lipidation at their C-termini, which is presumed to confer additional membrane binding.
View Article and Find Full Text PDFInt J Mol Sci
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Department of Molecular Biology and Genetics, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey.
Fucosidosis is a rare lysosomal storage disease caused by α-L-fucosidase deficiency following a mutation in the gene. This enzyme is responsible for breaking down fucose-containing glycoproteins, glycolipids, and oligosaccharides within the lysosome. Mutations in result in either reduced enzyme activity or complete loss of function, leading to the accumulation of fucose-rich substrates in lysosomes.
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