{"title":"Design of a Multi-Epitope Vaccine using β-barrel Outer Membrane Proteins Identified in Chlamydia trachomatis.","authors":"Amisha Panda, Jahnvi Kapoor, B Hareramadas, Ilmas Naqvi, Satish Ganta, Ravindresh Chhabra, Sanjiv Kumar, Anannya Bandyopadhyay","doi":"10.1007/s00232-025-00360-5","DOIUrl":"https://doi.org/10.1007/s00232-025-00360-5","url":null,"abstract":"<p><p>Chlamydia trachomatis is an obligate intracellular Gram-negative pathogen that causes sexually transmitted infections (STIs) and trachoma. Current interventions are limited due to the widespread nature of asymptomatic infections, and the absence of a licensed vaccine exacerbates the challenge. In this study, we predicted outer membrane β-barrel (OMBB) proteins and designed a multi-epitope vaccine (MEV) construct using identified proteins. We employed a consensus-based computational framework on the C. trachomatis D/UW-3/CX proteome and identified 17 OMBB proteins, including well-known Pmp family members and MOMP. Eight OMBB proteins were computationally characterized, showing significant structural homology with known outer membrane proteins from other bacteria. Sequence-based annotation tools were used to determine their putative functions. B-cell and T-cell epitopes were predicted from the selected proteins. The MEV construct was designed using four cytotoxic T-lymphocyte (CTL) epitopes and 29 helper T-lymphocyte (HTL) epitopes from six OMBB proteins, which were conserved across 106 C. trachomatis serovars. To enhance its immunogenicity, the vaccine was supplemented with the Cholera toxin B subunit and PADRE sequence at the N-terminus. The MEV construct, of length 780 amino acids, was predicted to be antigenic, non-allergenic, non-toxic, and soluble. Secondary structure analysis revealed 95% random coils. A three-dimensional structural model of the MEV was generated and subsequently validated. Molecular docking between MEV and toll-like receptor 4 (TLR4) revealed strong and stable binding interactions. The MEV-TLR4 complex was found to be structurally compact and stable using molecular dynamics simulation. Immune simulation of the MEV construct elicited a strong immune response. This study highlights OMBB proteins as promising immunogenic targets and presents a computationally designed MEV candidate for C. trachomatis infection.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144994128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hypoxia Modulates Membrane Mechanics in Pancreatic Cancer.","authors":"Prema Kumari Agarwala, Shobhna Kapoor","doi":"10.1007/s00232-025-00358-z","DOIUrl":"https://doi.org/10.1007/s00232-025-00358-z","url":null,"abstract":"<p><p>Aggressive cancer cells such as pancreatic cells exhibit an enhanced metastatic phenotype that involves cell migration and invasion. Cellular membrane deformation is a key process implicit in cell movement. This implicates a link between altered lipid metabolism during cancer progression and modulated membrane properties and hence associated functions. One of the key factors underlying the aggressiveness of pancreatic cancer is the presence of the highest percentage of hypoxia, which further adds to the lipid metabolic reprogramming. The subsequent effect of hypoxia-induced lipidome changes on membrane properties governing cell movement was investigated in this work using a combination of cell biology, microscopy, and spectroscopy. Our findings revealed that hypoxia induces distinct lipidome signatures in a cell-line-dependent fashion, which in turn differentially modulates the cell membrane stiffness. The correlation of cell stiffness with other membrane properties and the actin cytoskeleton shows a random correlation indicating that hypoxic stress distinctly regulates specific membrane attributes governing cellular functioning and should be consulted for the development of effective treatments for pancreatic cancer.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144876537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pore Formation by Pore Forming Proteins in Lipid Membranes: Structural Insights Through Cryo-EM.","authors":"Arnab Chatterjee, Prasenjit Naskar, Suman Mishra, Somnath Dutta","doi":"10.1007/s00232-025-00344-5","DOIUrl":"10.1007/s00232-025-00344-5","url":null,"abstract":"<p><p>Many pathogenic bacteria utilize their complicated appalling arsenal, bacterial virulence factors, to attack host cells by damaging the host cell membrane and neutralizing host defense mechanisms. Bacterial pore-forming proteins (PFPs) are one of them, they include a distinct class of secreted soluble toxin monomers, which binds to the specific cell surface receptors and /or lipids, oligomerizes as an amphipathic transmembrane pore complex on host cell membranes, and deforms the integrity of the plasma membrane. Researchers have focused on characterizing the structure and function of different Pore Forming Toxins (PFTs) from various organisms, where most of the structural studies employed X-ray crystallography, single-particle cryo-EM, and cryo-electron tomography. However, historically, most of these previous studies focused on using detergent to solubilize and oligomerize the PFTs. Additionally, previous studies have also shown that lipid membranes and lipid components, including cell surface receptors, play a critical role in pore formation and oligomerization. However, there are limited studies available that aim to resolve the structure and function of PFTs in liposomes. In this review article, we majorly focused on structural and functional studies of pore-forming toxins in the presence of detergents, lipid nanodiscs, and liposomes. We will also discuss the challenges and benefits of using liposomes to study pore-forming proteins in more biologically relevant membrane environments.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"305-322"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bill H T Ho, Bradley A Spicer, Michelle A Dunstone
{"title":"Action of the Terminal Complement Pathway on Cell Membranes.","authors":"Bill H T Ho, Bradley A Spicer, Michelle A Dunstone","doi":"10.1007/s00232-025-00343-6","DOIUrl":"10.1007/s00232-025-00343-6","url":null,"abstract":"<p><p>The complement pathway is one of the most ancient elements of the host's innate response and includes a set of protein effectors that rapidly react against pathogens. The late stages of the complement reaction are broadly categorised into two major outcomes. Firstly, C5a receptors, expressed on membranes of host cells, are activated by C5a to generate pro-inflammatory responses. Secondly, target cells are lysed by a hetero-oligomeric pore known as the membrane attack complex (MAC) that punctures the cellular membrane, causing ion and osmotic flux. Generally, several membrane-bound and soluble inhibitors protect the host membrane from complement damage. This includes inhibitors against the MAC, such as clusterin and CD59. This review addresses the most recent molecular and structural insights behind the activation and modulation of the integral membrane proteins, the C5a receptors (C5aR1 and C5aR2), as well as the regulation of MAC assembly. The second aspect of the review focuses on the molecular basis behind inflammatory diseases that are reflective of failure to regulate the terminal complement effectors. Although each arm is unique in its function, both pathways may share similar outcomes in these diseases. As such, the review outlines potential synergy and crosstalk between C5a receptor activation and MAC-mediated cellular responses.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"269-304"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12313776/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143694291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Introduction to Special Issue on Role of Membranes in the Pore-Formation Mechanism of Pore-Forming Proteins and Toxins.","authors":"Kausik Chattopadhyay","doi":"10.1007/s00232-025-00353-4","DOIUrl":"10.1007/s00232-025-00353-4","url":null,"abstract":"","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"253-254"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144486810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samlesh Choudhury, Bharath Desikan, K Ganapathy Ayappa
{"title":"Oxysterols Outcompete Cholesterol Binding to the Membrane-Inserted Cytolysin A Pore Complex.","authors":"Samlesh Choudhury, Bharath Desikan, K Ganapathy Ayappa","doi":"10.1007/s00232-025-00349-0","DOIUrl":"10.1007/s00232-025-00349-0","url":null,"abstract":"<p><p>Pore-forming toxins (PFTs) belong to a class of proteins expressed by bacteria to initiate infections by unregulated pore formation on the plasma membrane of host cells. Although cholesterol is a key sterol motif that promotes toxin activity, the influence of oxysterols, upregulated in senescent cells or in other inflammatory disorders, on lytic activity has not received much attention. Using all-atom molecular dynamics simulations, we study the changes to the sterol binding landscape of membrane-inserted cytolysin A (ClyA), an <math><mi>α</mi></math> -PFT expressed by E. coli, in the presence of tail-oxidized 25-hydroxycholesterol (25-HC) in a palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC):cholesterol:25-HC (70:20:10) membrane. 25-HC was found to entirely replace previously identified cholesterol binding hotspots [PNAS,115 7323-7330] between the membrane-inserted <math><mi>β</mi></math> -tongue motifs with binding lifetimes on the order of microseconds. Although the overall sterol occupancy is lower for the N-terminal helix motif that forms the lining of the water channel, 25-HC binding is less when compared with cholesterol. The presence of the additional OH group on the 25th carbon enhances interactions with polar residues of the <math><mi>β</mi></math> -tongue, increasing 25-HC binding times by several fold when compared with cholesterol. We discuss the implications of this enhanced oxysterol interaction on pore formation of the <math><mi>α</mi></math> family of toxins such as ClyA, in contrast with the cholesterol-dependent cytolysins, where oxysterols have been shown to be detrimental to pore formation.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"341-352"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144250608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to: Introduction to Special Issue on Role of Membranes in the Pore-Formation Mechanism of Pore-Forming Proteins and Toxins.","authors":"Kausik Chattopadhyay","doi":"10.1007/s00232-025-00356-1","DOIUrl":"10.1007/s00232-025-00356-1","url":null,"abstract":"","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"255"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144610228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Remya Satheesan, Asuma Janeena, Kozhinjampara R Mahendran
{"title":"Hetero-Oligomeric Protein Pores for Single-Molecule Sensing.","authors":"Remya Satheesan, Asuma Janeena, Kozhinjampara R Mahendran","doi":"10.1007/s00232-024-00331-2","DOIUrl":"10.1007/s00232-024-00331-2","url":null,"abstract":"<p><p>Protein nanopores are emerging as versatile single-molecule sensors with broad applications in DNA and protein sequencing. However, their narrow size restricts the range of detectable analytes, necessitating the development of advanced nanopores to broaden their applications in biotechnology. This review highlights a natural hetero-oligomeric porin, Nocardia farcinica porin AB (NfpAB), based on the Gram-positive mycolata, Nocardia farcinica. The pore comprises two subunits, NfpA and NfpB, that combine to form a stable structure with a unique pore geometry, asymmetrical shape, and charge distribution. Single-channel electrical recordings demonstrate that NfpAB forms stable, high-conductance channels suitable for sensing charged molecules, particularly cationic polypeptides and cyclic sugars. This pore offers advantages such as enhanced control over molecular interactions due to densely crowded charged residues, thus allowing the quantification of voltage-dependent translocation kinetics. Notably, NfpAB contains intrinsic cysteines in the pore lumen, providing an accessible site for thiol-based reactions and attachment of molecular adapters. We propose that such hetero-oligomeric pores will be effective for several applications in nanopore technology for biomolecular detection and sequencing.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":"257-267"},"PeriodicalIF":2.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142856535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saqib Rabbani, Areesha Maryam, Muhammad Sohail, Athar Yaseen Khan
{"title":"Molecular Insights into Interactions between Ofloxacin and Ionic Micelles.","authors":"Saqib Rabbani, Areesha Maryam, Muhammad Sohail, Athar Yaseen Khan","doi":"10.1007/s00232-025-00357-0","DOIUrl":"https://doi.org/10.1007/s00232-025-00357-0","url":null,"abstract":"<p><p>The growing antimicrobial resistance presents a challenge in developing new potent drugs, but this effort is hindered by a lack of information regarding how these new drugs would behave in biomembranes. Surfactants are considered mimetic models for biomembranes and can be used to study drug-membrane interactions. In this study, we used two well-known surfactants-cationic cetyltrimethylammonium bromide and anionic sodium dodecyl sulfate-as model membranes to investigate their interaction with the antimicrobial drug ofloxacin (OFL). These interactions were studied using volumetric and acoustic methods over the temperature range of 293.15-323.15 K to determine the apparent molar volume, isentropic compressibility, apparent molar compressibility, acoustic impedance, relative association, and intermolecular free length. Furthermore, UV-Vis spectroscopy and cyclic voltammetry were employed to evaluate the binding constants and free energies of the drug-surfactant systems. These results provide key molecular insights into the thermodynamics of OFL partitioning and its binding mechanisms with amphiphilic assemblies. Such mechanistic understanding is crucial for the rational design of antibiotic delivery systems, facilitating precise control over drug loading and release dynamics in surfactant-based formulations.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144692248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stomatin and Stomatin-Like Proteins Can Regulate Transporter Proteins Activity and Has a Role in Cancer Metastasis.","authors":"Abira Dey, Debabani Ganguly","doi":"10.1007/s00232-025-00355-2","DOIUrl":"https://doi.org/10.1007/s00232-025-00355-2","url":null,"abstract":"<p><p>Stomatin, encoded by STOM gene, is an integral membrane protein found in a wide variety of species. Although years have passed since the identification of stomatin, little has been known about the functional insights of stomatin among which stomatin undergoing homo-oligomerization, post and reverse-post modifications are the notable ones. Stomatin downregulation or overexpression is directly connected to its ability to control neutrophil degranulation, modulate activities of transporter proteins, and mediate cancer metastasis. Stomatin shares about 40-80% sequence similarity at its signature SPFH (stomatin, prohibitin, flotillin and Hlfk) domain region with the stomatin-like proteins (SLPs). Although stomatin and SLPs are reported to have various therapeutic activities, still gaps are there regarding their plausible mechanistic insights. Therefore, in future, studies should be aimed toward investigating the possible mechanistic pathways controlled by stomatin and SLPs which can be employed to understand the basis of many therapeutic targets. This review briefs about the different functions of stomatin focusing mainly on the transporter proteins and carcinogenicity modulation by stomatin and SLPs.</p>","PeriodicalId":50129,"journal":{"name":"Journal of Membrane Biology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144602149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}