Biophysical chemistry最新文献

{"title":"Interaction process behind the strong stabilization of G-quadruplexes by alkaloid fagaronine","authors":"Pavel Hannig ,&nbsp;Raimundo Gargallo ,&nbsp;Stefania Mazzini ,&nbsp;Gigliola Borgonovo ,&nbsp;Marco Zuccolo ,&nbsp;Eva Táborská ,&nbsp;Petr Táborský","doi":"10.1016/j.bpc.2025.107443","DOIUrl":"10.1016/j.bpc.2025.107443","url":null,"abstract":"<div><div>Benzo[<em>c</em>]phenanthridine alkaloids are known for their stabilizing effects on non-canonical DNA structures, particularly G-quadruplexes (G4s). In this study, the interaction of fagaronine, a rare benzo[<em>c</em>]phenanthridine alkaloid, with several DNA structures (including B-DNA, parallel, antiparallel and hybrid G4s) is studied using molecular fluorescence and circular dichroism (CD) spectroscopy. It has been found that fagaronine significantly enhances the stability of all tested G4 conformations. Furthermore, a study by NMR spectroscopy provided valuable information on the mechanism of interaction of the ligand with the parallel G4 structure adopted by Pu22T14T23, a sequence mutated with respect to that found within the promoter region of the <em>c-myc</em> gene. Remarkably, when compared with data reported in the literature, fagaronine appears to exhibit one of the strongest G4 thermal stabilization effects ever recorded for a small ligand.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"323 ","pages":"Article 107443"},"PeriodicalIF":3.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844707","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":"Green synthesis, characterization, structural, morphological, antibacterial, and cytotoxicity evaluation of zinc oxide nanoparticles using Fioria vitifolia extract","authors":"A. Nandhini ,&nbsp;P. Anilkumar ,&nbsp;J. Jasmin ,&nbsp;S. Balamurali","doi":"10.1016/j.bpc.2025.107440","DOIUrl":"10.1016/j.bpc.2025.107440","url":null,"abstract":"<div><div>The increasing prevalence of bacterial pathogens diseases and the rise in multidrug resistance highlights the urgent need for new drug delivery systems or novel drug molecules to enhance treatment options. Zinc oxide (ZnO) nanoparticles attracting attention due to their potential in biomedical applications, such as cancer therapy and diagnostics. ZnO is a versatile compound with excellent UV-blocking, anti-inflammatory, and wide-bandgap semiconductor properties. This study focuses on the green synthesis of ZnO nanoparticles using ‘<em>Fioria vitifolia’</em> leaf extract, as a reducing agent with polyvinylpyrrolidone (PVP) aids in reducing particle size and preventing aggregation, enhancing nanoparticle stability. The ZnO nanoparticles were characterized using various techniques, including X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Analysis (EDX), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), UV–Vis Diffuse Reflectance Spectroscopy (DRS), and Photoluminescence (PL). These analyses confirmed the successful formation of ZnO nanoparticles. The nanoparticles demonstrated strong antimicrobial activity, especially against ‘<em>Enterobacter’</em>, and exhibited significant cytotoxic effects on lung cancer cells (A549), but has low toxicity to standard cells (L929). The IC₅₀ values affirmed their potential as anticancer agents, suggesting their dual promise as antimicrobial and anticancer compounds. The enormous potential of biosynthesized ZnO nanoparticles as biological agents a sustainable substitute for chemically synthesized medications is highlighted in this study. The potential of the nanoparticles in a range of biomedical applications is highlighted by their ecologically friendly manufacturing process as well as their proven antibacterial and anticancer qualities.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"323 ","pages":"Article 107440"},"PeriodicalIF":3.3,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874109","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":"Degree–based topological indices, NMR chemical shifts, chemical reactivity, molecular dynamics and DFT analysis of 1,4-Methanoazulene-9-methanol, Decahydro-4,8,8-trimethyl-, [1S-(1α,3aβ,4α,8aβ,9R)]","authors":"Jeffrin JA Laura ,&nbsp;P. Rajesh ,&nbsp;M. Kesavan ,&nbsp;E. Dhanalakshmi ,&nbsp;S. Kayashrini ,&nbsp;M. Prabhaharan","doi":"10.1016/j.bpc.2025.107442","DOIUrl":"10.1016/j.bpc.2025.107442","url":null,"abstract":"<div><div>This study aims to comprehensively analyze the structural, vibrational, and electrical characteristics of 11,4-Methanoazulene-9-methanol, decahydro-4,8,8-trimethyl-, [1S-(1α,3aβ,4α,8aβ,9R*)] (MMDT) with a focus on its potential as a therapeutic agent for liver cancer. The compound was isolated from <em>Hybanthus enneaspermus</em> using Soxhlet extraction, followed by Gas Chromatography-Mass Spectrometry (GC–MS) analysis. The structure optimization and vibrational frequency assignments were done using Density Functional Theory (DFT) method with the B3LYP/6–311++G (d, p) basis set. Natural Bond Orbital (NBO) analysis was conducted to explore intramolecular and intermolecular interactions, along with the first-order hyperpolarizability. Electronic properties such as the energy gap and molecular electrostatic potential (MEP), were calculated to anticipate reactive sites for electrophilic and nucleophilic attacks. This is crucial in understanding the compound's reactivity in biological systems. TD-DFT was employed to simulate UV–visible spectra and compared with experimental values. Additionally, the theoretical FTIR spectra were correlated with experimental data, with potential energy distribution (PED%) providing detailed vibrational mode analysis. HOMO and LUMO orbitals were evaluated in the gas phase, revealing key energy parameters. ¹H and ¹³C NMR chemical shifts have been properly assigned using the DFT for structural characterization. QSPR/QSAR analysis is made simpler by determining a few topological indices for the MMDT. This study provides a novel computational framework for MMDT paving the way for faster, cost-effective and the Molecular docking studies revealed stable interactions between MMDT and liver cancer-related receptors, with favourable binding energy values along with Ramachandran plot confirmed the stability of the protein-ligand complex could be a promising candidate for liver cancer treatment.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107442"},"PeriodicalIF":3.3,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816978","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":"Receptor modulated assembly and drug induced disassembly of amyloid beta aggregates at asymmetric neuronal model biomembranes","authors":"Nirod Kumar Sarangi ,&nbsp;Subrata Mondal ,&nbsp;Tia E. Keyes","doi":"10.1016/j.bpc.2025.107441","DOIUrl":"10.1016/j.bpc.2025.107441","url":null,"abstract":"<div><div>Amyloid peptide non-fibrillar oligomers cause neurotoxicity and may contribute to Alzheimer's disease (AD) pathogenesis. Mounting evidence indicates that Aβ_1–42 oligomers disrupt and remodel neuronal membrane, causing neuronal cell death. The involvement of individual neuronal membrane constituents in real-time Aβ_1–42 aggregate assembly is unclear due to complexity of neuronal cell membrane. We used non-Faradaic electrochemical impedance spectroscopy (EIS) to track monomeric Aβ_1–42 peptide binding and aggregation pathways in real-time in asymmetric micropore suspended lipid bilayer membranes with anionic phospholipids and glycosphingolipids. Anionic DOPC:PIP2 pore suspended membrane showed pore-formation within 2 h of incubation, but peptide insertion occurred over 6 h, with an onset time of ∼6–8 h for peptide aggregation at the membrane surface. Among different gangliosides, peptide binding to GM1- and GM3-containing membranes did not result pore development, but receptor mediated peptide aggregation formation caused membrane admittance to decrease within 2 h. In contrast, partial peptide insertion in the membrane surface increases membrane admittance at GD1a and mixed GSL membranes, arresting aggregation. Time-lapsed AFM imaging at asymmetric solid supported lipid bilayers (aSLBs) corroborated EIS findings, capturing pore-formation and receptor mediated peptide assembly routes. Fluorescence lifetime imaging (FLIM) imaging and spatial resolved single-point fluorescence correlation spectroscopy (FCS) at aSLBs revealed membrane-peptide interaction, assembly, and peptide induced membrane reorganization. Treatment with antidepressants fluoxetine and imipramine therapeutics, in synergy, which are cost-effective and capable of crossing the central nervous system (CNS+), resulted in the disassembly of membrane mediated Aβ_1–42 aggregates, but not fibrils. Overall, the data suggests that membrane-mediated aggregate disassembly at the correct timing of AD progression may halt or reverse amyloid assembly through the use of repurposed drugs.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107441"},"PeriodicalIF":3.3,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interaction of Myrsinoic acid a with biomembrane models: Differential effects on DPPC and DPPS properties revealed by surface rheology and vibrational spectroscopy","authors":"Ana Gabrieli A. dos Santos,&nbsp;Fernando Cassas,&nbsp;Kevin Figueiredo dos Santos,&nbsp;Livia Soman de Medeiros,&nbsp;Thiago André Moura Veiga,&nbsp;Luciano Caseli","doi":"10.1016/j.bpc.2025.107439","DOIUrl":"10.1016/j.bpc.2025.107439","url":null,"abstract":"<div><div>This study investigates the interactions of Myrsinoic acid A, a natural compound with reported anti-inflammatory and antitumor properties, with lipid monolayers composed of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylserine (DPPS). Utilizing tensiometry, polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS), Brewster Angle Microscopy (BAM), and surface rheology, we analyzed how Myrsinoic acid A affects the structural and mechanical properties of these lipid systems. The PM-IRRAS spectra revealed that Myrsinoic acid A induced disorder in the DPPC monolayer, shifting CH₂ asymmetric stretching peaks and decreasing packing order, while DPPS remained structurally stable. Surface rheology measurements showed reduced elasticity in both lipids, with differential effects on viscosity: a decrease for DPPC and an increase for DPPS, indicating varied molecular interactions. BAM images confirmed that DPPC maintained a homogeneous morphology, while DPPS displayed aggregate formation, suggesting distinct lipid-drug interactions. These findings highlight the importance of lipid composition in modulating the effects of Myrsinoic acid A on membrane properties, providing insights into its potential therapeutic applications in targeting tumorigenic versus non-tumorigenic cells.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107439"},"PeriodicalIF":3.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739617","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":"Phenolic fractions of Heliotropium Bacciferum inhibit human insulin aggregation and protect against amyloid-induced cytotoxicity: Structural and biophysical analysis","authors":"Moneera Saud Al-Bagmi ,&nbsp;Majed S. Alokail ,&nbsp;Nasser M. Al-Daghri ,&nbsp;Nojood Altwaijry ,&nbsp;Ibrahim M. Aziz ,&nbsp;Fahad N. Almajhdi ,&nbsp;Mohd Shahnawaz Khan","doi":"10.1016/j.bpc.2025.107437","DOIUrl":"10.1016/j.bpc.2025.107437","url":null,"abstract":"<div><div>In humans, more than 50 diseases are related to protein fibrillation, including Alzheimer's and Parkinson's diseases. Inhibition of amyloid fibril formation using natural products is one of the main therapeutic strategies for preventing the progression of these diseases. In this context, phenolic extract fractions from <em>Heliotropium bacciferum</em> leaves were evaluated for their ability to inhibit the aggregation of human insulin (HI), an appropriate model protein for fibrillation under physiological conditions and agitation at 600 rpm. Our results exhibited HI fibrillation under studied conditions, with aggregation kinetic fitting a sigmoidal curve with <span><math><msub><mi>t</mi><mi>lag</mi></msub></math></span> and <span><math><msub><mi>k</mi><mi>app</mi></msub></math></span> values of 44.4 h and 0.16 h⁻¹, respectively. Structural changes preceding the onset of fibril formation were detected by 8-Anilino-1-naphthalene-sulphonic acid (ANS) probe, revealed the exposure of hydrophobic regions in the HI peptide to the solvent, with <span><math><msub><mi>t</mi><mi>lag</mi></msub></math></span> and <span><math><msub><mi>k</mi><mi>app</mi></msub></math></span> values of 18.2 h 0.12 h⁻¹, respectively. CD spectroscopy calculated the formed fibrils comprised of 51.6 % β-sheet structure and 43.0 % unordered structure. In vitro studies demonstrated a dose-dependent inhibitory effect of <em>H. bacciferum</em> extracts on HI fibrillation. The free phenolic fraction (FPF) at 200 μg/mL exhibited nearly complete inhibition, whereas the bound phenolic fraction (BPF) demonstrated a 52 % reduction in fibrillation. These findings were further validated using Rayleigh light scattering (RLS) and circular dichroism analyses. Transmission electron microscopy (TEM) validated the formation of insulin fibrillation and its inhibition by extract fractions. Moreover, MTT assay results on SH-SY5Y cells showed that both extract fractions attenuated HI fibril-induced neuronal toxicity in a dose-dependent manner. Furthermore, RT-PCR analysis revealed that co-treatment with a low concentration (7.8 μg/mL) of <em>H. bacciferum</em> extracts led to a significant reduction in the expression levels of pro-apoptotic genes (Casp3 and Bax) and an increase in the anti-apoptotic gene Bcl-2 in SH-SY5Y cells treated with fibrillated HI. This study highlights the potential of <em>H. bacciferum</em> extracts as therapeutic agents against protein fibrillation-related diseases and underscores the importance of polyphenols in preventing amyloid fibril formation.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107437"},"PeriodicalIF":3.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817579","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 amyloidogenic peptide stretch in human tau, tau306–311 is a promising injectable hydrogelator","authors":"Shubhangini Singh Verma,&nbsp;Shinjini Bhattacharya,&nbsp;Sachin Kumar,&nbsp;Nitin Chaudhary","doi":"10.1016/j.bpc.2025.107438","DOIUrl":"10.1016/j.bpc.2025.107438","url":null,"abstract":"<div><div>A vast majority of peptide hydrogelators harbor a bulky, non-native aromatic moiety. Such foreign moieties raise safety concerns as far as biomedical applications of hydrogels are concerned. The hydrogel research, therefore, has branched to another dimension – to identify native or native-like short peptide stretches that could cause the gelation of biological fluids. Using well-defined criteria to identify native peptide stretches that could form a viscous solution in water but cause gelation of phosphate-buffered saline (PBS), we identified the hexapeptide stretch from human tau, <em>viz.</em> tau^306–311, as a promising injectable hydrogelator. The peptide causes instant gelation of PBS and the cell culture media. Such hydrogels find applications as drug delivery vehicles, scaffolds for mammalian cell culture, wound-dressing material, <em>etc.</em></div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107438"},"PeriodicalIF":3.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726140","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":"Characterization of metabolism associated with outcomes in severe acute pancreatitis: Insights from serum metabolomic analysis","authors":"Mohd Adnan Siddiqui ,&nbsp;Anamika Singh ,&nbsp;Swarnima Pandey ,&nbsp;Mohammed Haris Siddiqui ,&nbsp;Afzal Azim ,&nbsp;Neeraj Sinha","doi":"10.1016/j.bpc.2025.107436","DOIUrl":"10.1016/j.bpc.2025.107436","url":null,"abstract":"<div><div>Severe Acute Pancreatitis (SAP) is characterized by an abrupt onset of pancreatic inflammation, which may induce damage to other organs, and is associated with significant morbidity and mortality. Despite the considerable disease burden, specific treatments to stop progression or prevent occurrence are limited. Currently, there is a paucity of comprehensive studies that thoroughly explore metabolic dysregulation in SAP, particularly those that emphasize changes in outcomes. Nuclear magnetic resonance (NMR) based metabolomics coupled with multivariate analysis was applied to serum samples of 20 survivors and 30 non-survivors of SAP to identify metabolic changes linked to different outcomes. The discriminant analysis of serum samples of SAP survivors and non-survivors revealed isoleucine, leucine, valine, arginine, lactate, and 3-hydroxybutyrate as significant metabolites elevated in the non-survivors. These identified metabolites had shown a significant positive correlation with clinical severity scores in the Pearson correlation analysis. Pathway analysis revealed disruptions in amino acid metabolism, driven by protein catabolism to fulfill the patient's energy requirements. This study highlights the importance of metabolomics in unraveling the molecular and physiological mechanisms underlying SAP. These findings offer valuable insights for clinicians to develop treatment strategies that target metabolic pathways in SAP, potentially for improving patient outcomes.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107436"},"PeriodicalIF":3.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643821","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":"A detailed review of genetically encodable RFPs and far-RFPs and their applications in advanced super-resolution imaging techniques","authors":"Jianshu Dong ,&nbsp;Bilal Tayyab ,&nbsp;Jiangyun Wang","doi":"10.1016/j.bpc.2025.107432","DOIUrl":"10.1016/j.bpc.2025.107432","url":null,"abstract":"<div><div>The red fluorescent proteins (RFPs) and far-red fluorescent proteins (far-RFPs) that are encoded genetically can emit fluorescence within the spectral ranges of 580–680 nm when exposed to the light of appropriate wavelengths. Unlike many RFPs derived from coral species, numerous far-RFPs are optimized synthetic constructs engineered from different orange or red-emitting progenitors. Various categories have been established for the available RFPs and far-red fluorescent proteins based on their photo-chemical profile, fluorescence mechanism, and switching kinetics. Fluorescent probes (FPs) derived from these classes are extensively utilized for labelling and visualizing in vivo and in vitro specimens. Traditional optical microscopy methods generate diffraction-limited, indistinct images owing to the restricted resolution capability of light ranging from 200 to 300 nm. Since 2005, super-resolution microscopy has been a topic of great interest due to its ability to achieve imaging at spatial resolutions of less than 100 nm. The 2014 Nobel Prize in Chemistry was awarded to Eric Betzig, Stefan Hell, and William E. Moerner for their contributions to demonstrating the effectiveness of genetically encodable fluorescent proteins in visualizing biological systems through super-resolution fluorescence microscopy. This review provides a concise overview of RFPs and far-RFPs, including the involvement of surrounding residues in chromophore intactness, stability, autocatalytic maturation and switching kinetics. All the chemical pathways proposed for photoactivation, photoconversion and photoswitching mechanisms are concisely reviewed. Subsequently, a comprehensive summary was provided regarding the various types of super-resolution techniques that are commonly employed, elucidating their underlying principles of operation, as well as the potential future applications of RFPs/far-RFPs in the field of biological imaging.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107432"},"PeriodicalIF":3.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143673287","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":"Interaction of native and aggregated albumin with DMPC bilayers","authors":"Brigitte Magdalena Merino ,&nbsp;Rosa Bartucci ,&nbsp;Rita Guzzi","doi":"10.1016/j.bpc.2025.107431","DOIUrl":"10.1016/j.bpc.2025.107431","url":null,"abstract":"<div><div>The study of protein-lipid interaction offers interesting insights into the mutual alterations determined in the formation of the supramolecular complex. It gains even more interest, not only in basic research but also in biomedical and biomaterial applications, when protein aggregation and fibril formation are involved. In this study, the reciprocal influence of human serum albumin (HSA), in both the native and the thermally aggregated state, and dimyristoylphosphatidylcholine (DMPC) bilayers is investigated by combining UV–Vis scattering, attenuated total reflection Fourier transform infrared (ATR-FTIR), and spin-label electron paramagnetic resonance (EPR) spectroscopies. Temperature-dependent optical density at fixed wavelength reveals the pre- and the main phase transitions in DMPC bilayers as well as the onset of protein aggregation at T_agg ≈ 70 °C. In native protein/lipid complexes, the protein adsorption on the membrane surfaces suppresses the pre-transition and downshifts the temperature of the main phase transitions of DMPC, whereas the presence of DMPC increases T_agg without affecting the thermal profile. Kinetics experiments reveal that lipid bilayers reduce the thermally-induced aggregation of the protein. ATR-FTIR data indicate that albumin weakens the hydrogen bonding network at the carbonyl groups of the membrane. Conversely, lipid bilayers in any physical state do not alter the structural features of both native and aggregated HSA. In protein/lipid complexes, spin-label EPR of the lipid component reveals that the proteins reduce the packing density of the first chain segments and stabilize the fluid state, the effect being more evident for the native protein.</div></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":"322 ","pages":"Article 107431"},"PeriodicalIF":3.3,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643820","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}