Biochimica et biophysica acta. Biomembranes最新文献

{"title":"α,ω-Hexadecanedioic acid induces proton-translocating decoupling at complex III via Q-cycle disruption: evidence from kinetic and structural analyses","authors":"Svetlana I. Pavlova , Victor N. Samartsev , Alexander V. Chulkov , Ekaterina I. Khoroshavina , Mikhail V. Dubinin","doi":"10.1016/j.bbamem.2025.184476","DOIUrl":"10.1016/j.bbamem.2025.184476","url":null,"abstract":"<div><div>This study investigates the interaction between α,ω-hexadecanedioic acid (HDA (<span><math><mi>D</mi></math></span>)) and сomplex III (<span><math><msub><mi>E</mi><mi>III</mi></msub></math></span>) electron transport chain in liver mitochondria, focusing on <span><math><mi>D</mi><msub><mi>E</mi><mi>III</mi></msub></math></span> complex formation during succinate and glutamate/malate oxidation. A key emphasis is placed on the “idling” state of <span><math><mi>D</mi><msub><mi>E</mi><mi>III</mi></msub></math></span>, where electron transfer occurs without proton translocation. The decoupling effect of HDA was quantified using three parameters: 1) <span><math><msubsup><mi>K</mi><mi>d</mi><mi>ap</mi></msubsup></math></span> and <span><math><msubsup><mi>K</mi><mi>d</mi><mo>∗</mo></msubsup></math></span>: apparent dissociation constants of the <span><math><mi>D</mi><msub><mi>E</mi><mi>III</mi></msub></math></span> complex, calculated based on the total HDA concentration and the HDA quantity within the mitochondrial effective volume, respectively; 2) <span><math><msub><mi>J</mi><mi>Dmax</mi></msub></math></span>: the maximal mitochondrial respiration rate under saturating HDA concentrations (as [HDA] approaches infinity); 3) <span><math><msub><mi>K</mi><mn>0.5</mn></msub></math></span>: the HDA concentration at which the decoupling effect (<span><math><msub><mi>J</mi><mi>D</mi></msub><mo>−</mo><msub><mi>J</mi><mn>4</mn></msub></math></span>) equals half of its maximal value (<span><math><msub><mi>J</mi><mi>Dmax</mi></msub><mo>−</mo><msub><mi>J</mi><mn>4</mn></msub></math></span>), where <span><math><msub><mi>J</mi><mn>4</mn></msub></math></span> represents the mitochondrial respiration rate in State 4. Methodologies for parameter determination were established through HDA concentration-dependent respiration profiles. Key findings reveal that <span><math><msubsup><mi>K</mi><mi>d</mi><mi>ap</mi></msubsup></math></span> remains substrate-independent but in contrast to <span><math><msubsup><mi>K</mi><mi>d</mi><mo>∗</mo></msubsup></math></span> varies with mitochondrial protein concentration. In contrast, <span><math><msub><mi>K</mi><mn>0.5</mn></msub></math></span> and <span><math><msub><mi>J</mi><mi>Dmax</mi></msub><mo>/</mo><msub><mi>J</mi><mn>4</mn></msub></math></span> were significantly higher during succinate oxidation compared to glutamate/malate. Classical protonophores 3,5-di(tret-butyl)-4-hydroxybenzylidenemalononitrile (SF6847) and 2,4-dinitrophenol (DNP), as well as chenodeoxycholic acid (CDCA) at low concentrations, increased <span><math><msubsup><mi>K</mi><mi>d</mi><mi>ap</mi></msubsup></math></span> without affecting <span><math><msub><mi>J</mi><mi>Dmax</mi></msub><mo>/</mo><msub><mi>J</mi><mn>4</mn></msub></math></span>, suggesting reduced HDA efficacy. Molecular docking identified potential HDA binding sites on сomplex III. Based on these findings, we discuss a possible mechanism underlying the decoupling action (intrinsic uncoupli","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184476"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145312257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reassessing DMSO–lipid interactions: Improved AMBER force fields emphasize solvent rather than bilayer effects in cryoprotection","authors":"Ivan Klbik ,&nbsp;Milan Melicherčík ,&nbsp;Dušan Račko ,&nbsp;Igor Maťko ,&nbsp;Ján Lakota ,&nbsp;Ondrej Šauša","doi":"10.1016/j.bbamem.2025.184481","DOIUrl":"10.1016/j.bbamem.2025.184481","url":null,"abstract":"<div><div>The interaction of dimethyl sulfoxide (DMSO) with lipid membranes has been extensively studied using molecular dynamics (MD) simulations, yet discrepancies with experimental findings persist. Here, we re-evaluate the effects of low DMSO concentrations (1.5–10 vol%) on dimyristoyl phosphatidylcholine (DMPC) membranes using updated AMBER force fields (LIPID17, OPC, GAFF2) to assess its cryoprotective role. Simulations were performed in both fluid (330<em>K</em>) and gel (260 K) phases as well as under ice-forming conditions. Across three independent replicas, no statistically significant effects of DMSO were detected on membrane thickness, area per lipid, hydration, or acyl-chain order, indicating that low levels of DMSO do not alter bilayer structure. This represents an improvement over earlier force-field descriptions, which often exaggerated DMSO–lipid interactions, and provides results more consistent with experimental evidence. DMSO showed mild enrichment at the hydrophobic–hydrophilic interface, particularly near carbonyl and glycerol groups, but most molecules remained in the solvent. The strongest effects therefore emerged in the solvent phase: DMSO slowed ice crystal growth by about a factor of five, was excluded from the ice lattice, and accumulated at the ice–membrane boundary forming an ice-free layer. Surprisingly, even without DMSO, ice formation in contact with the bilayer did not cause structural disruption, suggesting that cryoinjury involves additional membrane components beyond lipids. DMSO also strongly inhibited the temperature-driven variation of water density in the amorphous state. These findings suggest that at low concentrations, DMSO's cryoprotective action arises mainly from modulation of water and ice behavior rather than direct bilayer perturbation.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184481"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145480817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature, pressure and salt effects on bilayers of an acidic phospholipid, dipalmitoylphosphatidylglycerol","authors":"Masaki Goto ,&nbsp;Saeko Tanaka ,&nbsp;Nobutake Tamai ,&nbsp;Hitoshi Matsuki","doi":"10.1016/j.bbamem.2025.184462","DOIUrl":"10.1016/j.bbamem.2025.184462","url":null,"abstract":"<div><div>The effects of thermal pretreatments and a monovalent added salt (NaCl) on the thermotropic and barotropic bilayer phase behavior of an acidic phospholipid, dipalmitoylphosphatidylglycerol (DPPG), were investigated by differential scanning calorimetry, fluorometry and light transmittance measurements. At 1.0 mol kg⁻¹ NaCl concentration, lipid samples with static annealing treatments (i.e., cold storage) showed a transition from a metastable hydrated crystalline phase to the lamellar gel phase in addition to the pre- and the main transition. These transition temperatures increased with pressure and the interdigitated gel phase was induced under high pressure, which is similar to the bilayer phase behavior of dipalmitoylphosphatidylcholine. By contrast, lipid samples with dynamic annealing treatments (i.e., repeated freeze-thaw cycles) exhibited only a transition from the stable hydrated crystalline phase to the liquid crystalline phase accompanied by the morphological change in the bilayer aggregate. The transition temperature also increased with pressure and the phase behavior resembled that of dipalmitoylphosphatidylethanolamine. Regarding the salt effect, we found that the temperature–pressure phase diagrams of the non-annealed DPPG bilayer changed systematically with the salt concentration, demonstrating that the pressure-induced interdigitation is suppressed by the added salt. Thermodynamic quantities of the phase transitions increased with increasing salt concentration, suggesting that the DPPG bilayer was stabilized by the weakening of the electrostatic repulsion among the polar head groups due to the shielding effect. The concentration dependence of the minimum interdigitation pressure indicates the possibility that the interdigitation should occur even under atmospheric pressure in the absence of the salt.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184462"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between the structural transitions of DMPG membranes and the melting process, and their interaction with water","authors":"Thomas Heimburg ,&nbsp;Holger Ebel ,&nbsp;Peter Grabitz ,&nbsp;Julia Preu ,&nbsp;Yue Wang","doi":"10.1016/j.bbamem.2025.184475","DOIUrl":"10.1016/j.bbamem.2025.184475","url":null,"abstract":"<div><div>During the melting transition of dimyristoyl phosphatidylglycerol (DMPG), the order of the lipid chains and the three-dimensional, vesicular structural arrangement change simultaneously. These changes result in peculiar heat capacity profiles extended over a broad temperature range with several <span><math><msub><mrow><mi>c</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-maxima. Here, we present calorimetric, viscosity, and volume expansion coefficient data at various ionic strengths and charges. We propose a simple theory that explains the calorimetric data in terms of the coexistence of two membrane geometries, both of which can melt. During the transition, the equilibrium between these two geometries changes cooperatively. This equilibrium depends on the interactions between the membranes and the solvent, on the membrane’s charge and the ionic strength of the buffer. Solvent interactions also contribute to the volume change of the membrane phases. Unlike uncharged membranes, we find that enthalpy changes are no longer proportional to volume changes. Therefore, the pressure dependence of the calorimetric profiles differs from that of uncharged membranes. Our theory explains the pressure dependence of calorimetric profiles qualitatively and quantitatively. Furthermore, we demonstrate that the same theory can be used to describe pretransition and ripple formation in phosphatidylcholines. A key takeaway from this article is that solvent molecules (e.g., H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O) are part of the membrane and, in the case of DMPG, water cannot be considered a separate phase.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184475"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145278921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lateral lipid packing governs bilayer solubilization by styrene-maleic acid copolymers: a case study with cardiolipin-containing membranes","authors":"Joseph C. Iovine ,&nbsp;Benjamin T. Garrett ,&nbsp;Nathan N. Alder","doi":"10.1016/j.bbamem.2025.184470","DOIUrl":"10.1016/j.bbamem.2025.184470","url":null,"abstract":"<div><div>Styrene-maleic acid (SMA) copolymers are powerful tools for the detergent-free solubilization of biological membranes. Yet the influence of specific lipids on SMA activity remains an open question. Here, we examined the effects of the mitochondria-specific phospholipid cardiolipin on SMA-mediated membrane solubilization and its ability to form SMA-bound nanodiscs. To this end, we prepared a series of model membranes with cardiolipin and other test lipids with comparable surface charge and lateral packing characteristics. Using multiple independent experimental approaches, we found that cardiolipin inhibited SMA solubilization. Our results indicate that this effect was not attributable to headgroup charge effects, but related to cardiolipin-induced increase in lateral packing pressure at the interfacial region. Reduction of this lateral packing pressure using bilayer-active alcohols partially restored SMA solubilization. Our results highlight the importance of lipid geometry and packing in SMA nanodisc formation and could help guide the design of copolymers tailored to specific membranes.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184470"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145243668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patellamide–lipid interactions at the air–water interface: Biophysical insights into membrane modulation","authors":"Paulo Henrique Lima do Nascimento ,&nbsp;Kevin Figueiredo dos Santos ,&nbsp;Cristiano Giordani ,&nbsp;Joelle Mergola-Greef ,&nbsp;Marcel Jaspars ,&nbsp;Luciano Caseli","doi":"10.1016/j.bbamem.2025.184478","DOIUrl":"10.1016/j.bbamem.2025.184478","url":null,"abstract":"<div><div>Patellamides are cyclic pseudo-octapeptides derived from marine cyanobacteria with promising selective cytotoxic, antimicrobial, and neuroprotective activities. While their biological potential is increasingly recognized, the mechanisms underlying their interaction with lipid membranes remain poorly understood. In this study, we investigated the interfacial behavior of patellamide D using Langmuir monolayers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS), which model the outer leaflets of healthy and cancer cell membranes, respectively. Surface pressure–area isotherms, compressional modulus analysis, surface potential measurements, Brewster angle microscopy, Polarization-modulated infrared reflection-absorption spectroscopy, and interfacial rheology were employed to elucidate peptide–lipid interactions. Patellamide exhibited a lipid-specific condensing effect and induced subtle reorganization within the monolayers, particularly in anionic DPPS films. Despite these interactions, the compressional and viscoelastic properties of the monolayers were largely preserved, suggesting stable incorporation of the peptide without compromising film integrity. These findings reveal that patellamide can modulate lipid packing and interface properties in a selective and controlled manner. Such behavior underscores its potential in the design of membrane-active therapeutic agents and lipid-based drug delivery systems.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184478"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immobilized nanodisks for study of ligand binding interactions","authors":"Brandon S. Veron ,&nbsp;Kyle Lethcoe ,&nbsp;Robert O. Ryan","doi":"10.1016/j.bbamem.2025.184459","DOIUrl":"10.1016/j.bbamem.2025.184459","url":null,"abstract":"<div><div>The SpyCatcher/SpyTag system represents a unique technology that allows facile conjugation of proteins via formation of a covalent isopeptide bond between the 113 residue SpyCatcher protein and a 16 residue SpyTag peptide. Herein this technology was adapted to incorporate miniature bilayer membranes, termed nanodisks (ND). Fusion proteins comprised of apolipoprotein (apo) A-I/SpyTag peptide and SpyCatcher/maltose binding protein (MBP), respectively, were expressed and purified. Upon incubation of apoA-I:SpyTag fusion protein with SpyCatcher:MBP fusion protein, a covalent adduct was formed. ApoA-I:SpyTag formulated into ND particles with cardiolipin (CL) or phosphatidylcholine retained the ability to form an adduct with SpyCatcher:MBP. This adduct was then immobilized on amylose agarose resin beads through a binding interaction with the MBP component. Upon incubation of cytochrome <em>c</em> with immobilized CL ND, but not with phosphatidylcholine ND, cytochrome <em>c</em> binding occurred. When immobilized cytochrome <em>c</em> CL ND were incubated with buffer containing CaCl₂, cytochrome <em>c</em> dissociated and was recovered in the supernatant fraction obtained after pelleting the amylose agarose beads. Subsequent incubation of the amylose agarose beads with 10 mM maltose revealed that nearly all of the cytochrome <em>c</em> had been released from the beads. The data are consistent with the known ability of calcium to form an ionic interaction with the two negatively charged phosphates in the polar head group of CL. Given the number of ligand-membrane interactions that occur in nature, immobilized ND provide a novel means to probe them.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 8","pages":"Article 184459"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of TNAP activity and apatite formation in biomimetic matrix vesicles studied by 31P solid-state NMR","authors":"B.Z. Favarin ,&nbsp;N. Nassif ,&nbsp;T. Azaïs ,&nbsp;J. Guignier ,&nbsp;S. Mebarek ,&nbsp;R. Buchet ,&nbsp;J.L. Millán ,&nbsp;A.P. Ramos ,&nbsp;A.J. Costa-Filho ,&nbsp;P. Ciancaglini","doi":"10.1016/j.bbamem.2025.184446","DOIUrl":"10.1016/j.bbamem.2025.184446","url":null,"abstract":"<div><div>Skeletal and dental mineralization relies on a precisely regulated sequence of events culminating in apatite deposition onto collagen fibrils. Matrix vesicles (MVs), extracellular vesicles released by mineralization-competent cells, play a pivotal role in this process through the catalytic activity of alkaline phosphatase (TNAP). The lipid composition of MVs, particularly phosphatidylserine (PS)-calcium complexes, facilitates the nucleation of amorphous calcium phosphate and apatite formation. However, the interplay between the TNAP structure, the lipid membrane environment, and its enzymatic activity remains incompletely understood.</div><div>Biomimetic models of MVs, as proteoliposomes made with dipalmitoylphosphatidylcholine (DPPC) and various TNAP mutants, were used to investigate the TNAP's activity and mineralization potential. Molecular docking and site-directed mutagenesis revealed that specific cysteine substitutions near TNAP's catalytic and anchoring sites influence structural stability, enzymatic activity, and incorporation into lipid bilayers. Notably, TNAP mutants S221C and P307C exhibited enhanced catalytic efficiency in DPPC liposomes, while A420C showed reduced activity due to steric hindrance near the catalytic site. Solid-state NMR and cryo-TEM analyses confirmed hydroxyapatite formation, with significant contributions from lipid-anchored TNAP to the mineralization process.</div><div>These findings highlight the critical influence of the lipid environment on TNAP's functional properties and provide insights into the mechanisms governing biomineralization and related pathologies, including hypophosphatasia associated with various TNAP mutations. The study underscores the importance of ATP and pyrophosphate hydrolysis by TNAP in modulating apatite formation and reveals the role of specific TNAP mutations in regulating enzymatic activity, stability, and mineral propagation. Understanding these interactions could lead to alternate therapeutic strategies in treatment and regenerative medicine.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 8","pages":"Article 184446"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144940771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting prokaryotic ion channel by a chimera of fluorescent protein and artificial peptide toxin","authors":"Valentina A. Iunusova ,&nbsp;Nikita A. Orlov ,&nbsp;Oksana V. Nekrasova ,&nbsp;Alexey V. Feofanov ,&nbsp;Alexander A. Vassilevski ,&nbsp;Alexey I. Kuzmenkov","doi":"10.1016/j.bbamem.2025.184458","DOIUrl":"10.1016/j.bbamem.2025.184458","url":null,"abstract":"<div><div>KcsA, a potassium channel from <em>Streptomyces lividans</em>, is one of the most extensively studied transmembrane proteins. Despite significant research in structural biology, relatively few ligands of KcsA have been identified. One such ligand is Hui1, an artificial peptide derived from a phage display screening using a combinatorial library constructed relying on several sea anemone toxins. In this study, we engineered a fluorescent probe by fusing Hui1 with enhanced green fluorescent protein (eGFP), creating the first fluorescence-based tool to visualize prokaryotic ion channels. The eGFP–Hui1 chimera was successfully produced in <em>Escherichia coli</em> and purified using chromatographic techniques. Our study revealed a direct interaction between KcsA, also recombinantly expressed in <em>E. coli</em>, and the fluorescent chimera. Furthermore, we demonstrated that both Hui1 and tetraethylammonium can effectively displace the chimera from its complex with KcsA, confirming the specificity of the binding interaction. This approach opens new avenues for pharmacological and structural investigations, including the development of novel antimicrobial agents and high-throughput ligand screening.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 8","pages":"Article 184458"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining the thermotropic properties of large circularized nanodiscs","authors":"Mark J. Arcario ,&nbsp;Vikram Dalal ,&nbsp;David Fan ,&nbsp;Fong-Fu Hsu ,&nbsp;Wayland W.L. Cheng","doi":"10.1016/j.bbamem.2025.184451","DOIUrl":"10.1016/j.bbamem.2025.184451","url":null,"abstract":"<div><div>Nanodiscs, soluble membrane mimetics composed of an amphipathic membrane scaffold protein encircling a lipid bilayer, are widely used in biophysical and structural studies of membrane proteins. Because many membrane proteins are responsive to their membrane environment, through specific protein–lipid interactions and bulk membrane shape and structure, it is important to understand the properties of lipid bilayers contained within nanodiscs in order to interpret studies using this technology. Nanodiscs are known to alter lipid properties, such as membrane thickness and melting temperature, and interactions with the nanodisc rim have been hypothesized to produce local perturbations in lipid structure and dynamics. Larger nanodiscs should compensate for this effect with a larger unperturbed area. To test this hypothesis, we examined the lipid bilayer properties of several lipids (DMPC, DPPC, POPC, DSPC) and soy polar lipid in circularized nanodiscs of 11 nm to 50 nm diameter using the environmentally-sensitive fluorophore, Laurdan. In nanodiscs containing a single lipid type, as nanodisc size increased, lipid packing, melting temperature, and cooperativity better approximated the properties of that lipid in large unilamellar vesicles (LUVs). In spNW50 (50 nm nanodisc), the lipid packing and melting temperature were indistinguishable from LUVs. However, nanodiscs containing soy polar lipids did not follow this trend suggesting that complex lipid mixtures may produce preferential incorporation of lipids into the nanodisc or nonhomogeneous distribution of lipids within the nanodisc.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 8","pages":"Article 184451"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}