Biochimica et biophysica acta. Biomembranes最新文献

Lateral lipid packing governs bilayer solubilization by styrene-maleic acid copolymers: a case study with cardiolipin-containing membranes. 侧脂质填料支配着苯乙烯-马来酸共聚物的双层增溶：含心磷脂膜的案例研究。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-05 DOI: 10.1016/j.bbamem.2025.184470

Joseph C Iovine, Benjamin T Garrett, Nathan N Alder

{"title":"Lateral lipid packing governs bilayer solubilization by styrene-maleic acid copolymers: a case study with cardiolipin-containing membranes.","authors":"Joseph C Iovine, Benjamin T Garrett, Nathan N Alder","doi":"10.1016/j.bbamem.2025.184470","DOIUrl":"https://doi.org/10.1016/j.bbamem.2025.184470","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":" ","pages":"184470"},"PeriodicalIF":2.5,"publicationDate":"2025-10-05","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}

引用次数: 0

Transmembrane channel-like 4 (TMC4) could act as a negative regulator of KCNQ1 (Kv7.1) potassium channel 跨膜通道样4 （TMC4）可作为KCNQ1 （Kv7.1）钾通道的负调控因子。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-02 DOI: 10.1016/j.bbamem.2025.184460

Hirota Aoyagi, Koya Kawaguchi, Saori Yano-Nashimoto, Soichiro Yamaguchi

{"title":"Transmembrane channel-like 4 (TMC4) could act as a negative regulator of KCNQ1 (Kv7.1) potassium channel","authors":"Hirota Aoyagi, Koya Kawaguchi, Saori Yano-Nashimoto, Soichiro Yamaguchi","doi":"10.1016/j.bbamem.2025.184460","DOIUrl":"10.1016/j.bbamem.2025.184460","url":null,"abstract":"<div><div>TMC4 is a member of the transmembrane channel-like (TMC) protein family. In this family, TMC1 and TMC2 are thought to form the mechano-electrical transduction (MET) channel in the inner ear. On the other hand, the intrinsic functions of the other TMC family members (TMC3-8) are largely unknown. KCNQ1 (Kv7.1) channel is a voltage-gated potassium channel and plays crucial physiological roles with its auxiliary subunits, KCNE proteins (e.g. KCNQ1/KCNE1 complex contributes to cardiac repolarization, and KCNQ1/KCNE3 complex participates in epithelial ion transport). Recently, it was reported that TMC1 and TMC2 interacted with KCNQ1 and suppressed its K<sup>+</sup> currents. However, the relationships between KCNQ1 and the other TMC proteins have not been examined. Here, we show a novel interaction and a functional association between overexpressed TMC4 and KCNQ1. The Bead Halo assay and FRET analysis revealed the physical interaction between these two proteins. Whole-cell patch clamp recording demonstrated that co-expression of TMC4 reduced KCNQ1 current densities without altering their voltage dependence and activation kinetics. This effect was also observed in the KCNQ1/KCNE1 and KCNQ1/KCNE3 channel complexes. A structural prediction using AlphaFold-Multimer suggested possible interaction sites between TMC4 and KCNQ1. Mutageneses, followed by patch clamp recording, suggested that specific amino acid residues at these sites contribute to the inhibitory effect of TMC4. These results indicate that TMC4 could function as a negative regulator of the KCNQ1 channel. Our findings could enhance the understanding of KCNQ1 channel regulation and propose potential research directions on the function of TMC4 under various physiological and pathological conditions.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1868 1","pages":"Article 184460"},"PeriodicalIF":2.5,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228384","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}

引用次数: 0

Unveiling the impact of membrane fluidity in shaping lipid-based drug delivery systems development. 揭示膜流动性在塑造脂基药物输送系统发展中的影响。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-02 DOI: 10.1016/j.bbamem.2025.184461

Mariana Biscaia-Caleiras, Ana Sofia Lourenço, João Nuno Moreira, Sérgio Simões

{"title":"Unveiling the impact of membrane fluidity in shaping lipid-based drug delivery systems development.","authors":"Mariana Biscaia-Caleiras, Ana Sofia Lourenço, João Nuno Moreira, Sérgio Simões","doi":"10.1016/j.bbamem.2025.184461","DOIUrl":"https://doi.org/10.1016/j.bbamem.2025.184461","url":null,"abstract":"<p><p>Membrane fluidity is a fundamental property extensively studied in biological membranes and biophysical research, where it is critical to understanding membrane structure and function. However, its application in the development and manufacturing of lipid-based drug delivery systems, such as liposomes and lipid nanoparticles, remains underexplored. This mini-review shifts the focus toward the practical implications of membrane fluidity in pharmaceutical formulation and manufacturing. We highlight key factors influencing fluidity, such as temperature, lipid composition, and cholesterol content, and emphasize how understanding and controlling fluidity can serve as a critical quality attribute. The importance of these factors in modulating membrane dynamics is emphasized, revealing their potential to optimize liposomal formulations and manufacturing processes. Fluorescent probes such as DPH and Laurdan are also discussed for their ability to monitor fluidity in real-time, each presenting distinct advantages and limitations. Although its crucial role in lipid-based drug delivery systems, membrane fluidity remains a largely overlooked property. Deeper investigation is essential to fully understand its influence on membrane stability, therapeutic efficacy, and scalability. This mini-review advocates for a paradigm shift: recognizing membrane fluidity as a critical quality attribute that can be integrated into formulation development and industrial manufacturing frameworks to better predict and control product performance and process robustness.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":" ","pages":"184461"},"PeriodicalIF":2.5,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228377","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}

引用次数: 0

Temperature, pressure and salt effects on bilayers of an acidic phospholipid, dipalmitoylphosphatidylglycerol. 温度、压力和盐对酸性磷脂双棕榈酰磷脂酰甘油双层结构的影响。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-02 DOI: 10.1016/j.bbamem.2025.184462

Masaki Goto, Saeko Tanaka, Nobutake Tamai, Hitoshi Matsuki

{"title":"Temperature, pressure and salt effects on bilayers of an acidic phospholipid, dipalmitoylphosphatidylglycerol.","authors":"Masaki Goto, Saeko Tanaka, Nobutake Tamai, Hitoshi Matsuki","doi":"10.1016/j.bbamem.2025.184462","DOIUrl":"https://doi.org/10.1016/j.bbamem.2025.184462","url":null,"abstract":"<p><p>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<sup>-1</sup> 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.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":" ","pages":"184462"},"PeriodicalIF":2.5,"publicationDate":"2025-10-02","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}

引用次数: 0

Two phase coexistence in ternary mixtures of saturated and polyunsaturated phosphatidylcholines with cholesterol. 饱和和多不饱和磷脂酰胆碱与胆固醇三元混合物的两相共存。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-01 Epub Date: 2025-08-06 DOI: 10.1016/j.bbamem.2025.184436

James H Davis

引用次数: 0

Development of amyloid-cationic peptides with antimicrobial activities: Relation to their membranotropic activities. 具有抗菌活性的淀粉样阳离子肽的开发：与其膜性活性的关系。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-10-01 Epub Date: 2025-08-07 DOI: 10.1016/j.bbamem.2025.184439

Marta Balestra, Lilia Leghmizi, Thierry Drujon, Loïc Portier, Cillian Byrne, Fabienne Burlina, Sylvie Noinville

{"title":"Development of amyloid-cationic peptides with antimicrobial activities: Relation to their membranotropic activities.","authors":"Marta Balestra, Lilia Leghmizi, Thierry Drujon, Loïc Portier, Cillian Byrne, Fabienne Burlina, Sylvie Noinville","doi":"10.1016/j.bbamem.2025.184439","DOIUrl":"10.1016/j.bbamem.2025.184439","url":null,"abstract":"<p><p>We describe here a new class of antimicrobial peptides (named Amy-Cat) comprised of a short amyloid domain and a cationic domain, as a primary amphipathic structure. The nona-arginine sequence was chosen as the cationic motif, while the sequence and size of the amyloid domain was modulated. The Amy-Cat peptides were found to be bactericidal against gram-negative and gram-positive standard bacterial strains with minimum inhibitory concentrations ranging from 3 to 24 μM, and being well-below their hemolytic concentrations. Their membranotropic activities were investigated as a function of the amyloid sequence and compared to those of the nona-arginine peptide. Calcein dye leakage on lipid mimic models for bacterial and eukaryotic membranes was carried out. In addition, the effect of the amyloid moiety on the membrane binding and on the conformational change were investigated at the buffer/supported lipid bilayer interface using ATR-FTIR spectroscopy. The overall findings suggest optimum routes to balancing the hydrophobicity of the amyloid sequence over the fixed cationic sequence allowing selective disruption of the bacterial membranes without eliciting hemolysis. Amy-Cat peptides appear to be very promising candidates for the development of new antimicrobial agents.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":" ","pages":"184439"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811670","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}

引用次数: 0

Immobilized nanodisks for study of ligand binding interactions 用于配体结合相互作用研究的固定化纳米圆盘

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-09-22 DOI: 10.1016/j.bbamem.2025.184459

Brandon S. Veron , Kyle Lethcoe , Robert O. Ryan

{"title":"Immobilized nanodisks for study of ligand binding interactions","authors":"Brandon S. Veron , Kyle Lethcoe , 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 CaCl<sub>2</sub>, 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":"2025-09-22","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}

引用次数: 0

Targeting prokaryotic ion channel by a chimera of fluorescent protein and artificial peptide toxin 荧光蛋白与人工肽毒素嵌合体靶向原核离子通道。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-09-11 DOI: 10.1016/j.bbamem.2025.184458

Valentina A. Iunusova , Nikita A. Orlov , Oksana V. Nekrasova , Alexey V. Feofanov , Alexander A. Vassilevski , Alexey I. Kuzmenkov

{"title":"Targeting prokaryotic ion channel by a chimera of fluorescent protein and artificial peptide toxin","authors":"Valentina A. Iunusova , Nikita A. Orlov , Oksana V. Nekrasova , Alexey V. Feofanov , Alexander A. Vassilevski , 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":"2025-09-11","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}

引用次数: 0

Examining the thermotropic properties of large circularized nanodiscs 大型圆形纳米片的热致性研究

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-09-11 DOI: 10.1016/j.bbamem.2025.184451

Mark J. Arcario , Vikram Dalal , David Fan , Fong-Fu Hsu , Wayland W.L. Cheng

{"title":"Examining the thermotropic properties of large circularized nanodiscs","authors":"Mark J. Arcario , Vikram Dalal , David Fan , Fong-Fu Hsu , 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":"2025-09-11","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}

引用次数: 0

Small angle neutron scattering study of rhodopsin oligomerization and G-protein coupling in a physiologically relevant lipid membrane 生理相关脂质膜中紫红质寡聚和g蛋白偶联的小角中子散射研究。

IF 2.5 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2025-09-11 DOI: 10.1016/j.bbamem.2025.184454

Olivier Soubias , Jonathan D. Nickels , Kirk G. Hines , Walter E. Teague , John K. Northup , John Katsaras , Klaus Gawrisch

{"title":"Small angle neutron scattering study of rhodopsin oligomerization and G-protein coupling in a physiologically relevant lipid membrane","authors":"Olivier Soubias , Jonathan D. Nickels , Kirk G. Hines , Walter E. Teague , John K. Northup , John Katsaras , Klaus Gawrisch","doi":"10.1016/j.bbamem.2025.184454","DOIUrl":"10.1016/j.bbamem.2025.184454","url":null,"abstract":"<div><div>Although the oligomeric states of G-protein-coupled receptors (GPCRs) and interactions with cognate G proteins are central to their signal transduction capabilities, they remain poorly defined. In this study, we used small-angle neutron scattering (SANS) and a neutron contrast matching approach to elucidate the oligomeric states of the archetypal GPCR, rhodopsin, and its interaction with the G protein transducin (G<sub>t</sub>). At a rhodopsin/lipid molar ratio of 1/360, we found that dark-adapted rhodopsin exists as a monomer, a finding consistent with its high functional activity measured upon photoactivation by spectrophotometry and the rate of catalyzed [<sup>35</sup>S]-GTP-γ-S exchange. Following light activation, we observed that rhodopsin forms a stable 1:1 stoichiometric complex with G<sub>t</sub>, the structure of which is consistent with recent cryo-EM data. In contrast, activated rhodopsin in the absence of G<sub>t</sub> showed a propensity to form higher order oligomers. This research underscores the concentration-dependent nature of rhodopsin oligomerization and establishes SANS and the ability to produce appropriately contrast-matched samples, as a robust strategy for characterizing integral membrane protein interactions under biologically relevant conditions.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 8","pages":"Article 184454"},"PeriodicalIF":2.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058243","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}

引用次数: 0