Search Results (199)

Voltage-sensitive ion channels are glycoprotein macromolecules that carry ion currents across membranes of nerve and muscle fibers. The hypothesis presented helps explain the changes that convert an insulating ion channel into an ion conductor, stating that it undergoes a structural transformation on threshold reduction in the voltage across the membrane. Experimental data show that the excitable membrane is a ferroelectric liquid crystal. The Channel Activation by Electrostatic Repulsion hypothesis proposes the following: electrical attractions between boundary surface charges compress the polar channel into a compact smectic phase with induced dipoles. Critical depolarization eliminates surface charges and dipoles, decreasing the dielectric permittivity of the ion channel. This increases the repulsive electrostatic forces between positively charged residues in the four S4 segments. These forces form a selectivity filter dome and cause a proteinquake to a chiral nematic phase. The selectivity filter allows ions to enter as it strips their hydration waters. The permeant ions occupy hydrogen bonds of ion-conducting helices, displacing protons. Disordered regions between adjacent helices form liquid line defects. In the thermal chaos of physiological temperature, a line defect occasionally connects the inner and outer surfaces, forming a transient ion pathway that carries unpredictable surges of permeant ion currents, as observed in experiments. Tests for this hypothesis are proposed. Full article

The HIV-1 Env glycoprotein mediates both cell-free and cell-to-cell viral transmission and represents the primary target for protective humoral immune responses. Studies examining antibody neutralization of cell-free and cell-to-cell HIV transmission have found that cell-to-cell transmission is more resistant to neutralization. This resistance may be explained in part by antigenically distinct Env populations on virions and infected cells. Cell-surface Env may be more heterogeneous due to variations in cleavage, glycosylation, and conformational state. Nevertheless, the mechanisms that maintain antigenically distinct Env populations at the cell surface and on virions remain unclear, despite virion assembly occurring at the plasma membrane. In this focused review, we consider how Env endocytosis and recycling influence Env incorporation into virions and antibody recognition. We further consider how Env cleavage may influence trafficking and endocytic fate. Given the central role of Env’s cytoplasmic tail in engaging endosomal trafficking pathways, we review emerging structural models of the CT and discuss how its organization, symmetry, and conformational flexibility may contribute to Env trafficking and intracellular sorting. We also discuss how heterogeneous Env populations may influence antibody susceptibility. Finally, we review therapeutic strategies, including combinatorial antibodies and small-molecule Env modulators, that may enhance antibody recognition of infected cells and virions. Full article

Developing biodegradable and functional polymeric materials for active food packaging is essential to mitigate the environmental burden of petroleum-based plastics. In this context, gelatin/chitosan (G–Ch) nanofibrous mats were fabricated via solution blow spinning (SBS) and functionalized with snail slime (SS) and Pinus sylvestris essential oil (PSEO) to enhance their bioactivity and barrier performance. SS is rich in glycoproteins and natural bioactive compounds, while PSEO is characterized by terpene-based antimicrobial and antioxidant activities. SS and PSEO were incorporated into the G–Ch polymeric matrix to enhance the bioactivity, structural functionality and preservation performance of the nanofibrous mats. Three formulations (G–Ch, G–Ch–SS, and G–Ch–SS–10PSEO) were designed to elucidate the influence of snail slime and essential oil incorporation on the structure–property–function relationships of the nanofibrous mats. Morphological analysis revealed a smooth and bead-free fibrous structure across all formulations. The average fiber diameter (AFD) increased from 191.83 nm for G–Ch to 263.88 nm for G–Ch–SS and 295.83 nm for G–Ch–SS–10PSEO. FTIR and XRD analyses showed the physical encapsulation of the active compounds without significant chemical interactions. Furthermore, the incorporation of PSEO increased surface hydrophobicity and reduced air permeability, indicating the formation of a more compact fibrous structure with enhanced barrier properties. The functional performance of the nanofibrous mats was significantly improved by the addition of snail slime and PSEO. The G–Ch–SS–10PSEO formulation exhibited the highest antioxidant activity, reaching 36.8% for DPPH and 42.7% for ABTS, along with enhanced antibacterial efficacy against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Application tests on chicken wings demonstrated that the bioactive nanofibers effectively suppressed microbial growth, limited pH increases, and reduced lipid oxidation during 14 days of refrigerated storage. Overall, the results demonstrate that the synergistic integration of snail slime and essential oil within a biodegradable polymer matrix provides a promising strategy for designing active nanofibrous materials with enhanced structural and bioactive properties for sustainable food-packaging applications. Full article

Galectins are β-galactosyl-binding lectins with key roles in immune regulation and as pattern recognition receptors. To address their potential role(s) in viral infection of mucosal epithelia we currently investigate adhesion and entry mechanisms of the infectious hematopoietic necrosis virus (IHNV) using the zebrafish (Danio rerio) model system. We previously reported the recognition of IHNV envelope glycoprotein by the zebrafish galectin Drgal1-L2 and its inhibitory activity for viral adhesion to epithelial cells. Subsequently, we determined the structure of Drgal1-L2 and proposed a mechanism for Drgal1-mediated inhibition of IHNV spike fusion to the host epithelial cell. We now show that Drgal1 can also hinder viral adhesion and infection by binding to glycans on the host cell surface and epidermal mucus. We identified fibronectin, the reported IHNV receptor, as the cell surface glycoprotein recognized by Drgal1-L2. Surprisingly, IHNV also adhered in vitro to purified β1integrin, and pre-exposure of either IHNV or the immobilized β1integrin to Drgal1-L2 hindered IHNV adhesion. Binding of either anti-fibronectin or anti-β1integrin antibodies to the cell surface partially inhibited IHNV adherence. Drgal1-L2 also hindered IHNV adhesion by binding to mucus glycans. Taken together, our results suggest complementary mechanisms by which Drgal1-L2 may protect mucosal epithelial cells against IHNV infection and tentatively identify β1integrin as a novel receptor for IHNV. Full article

The search for novel antiviral agents against Newcastle disease virus (NDV) remains a priority in industrial poultry farming due to the virus’s high contagiousness and associated economic losses, prompting evaluation of polyene macrolides as potential therapeutic candidates. We employed a comprehensive approach combining computational modeling (molecular docking and dynamics simulation) and laboratory experiments to investigate the antiviral potential of natamycin, nystatin, and filipin complex against three NDV strains. Molecular docking analysis indicated binding sites for macrolides within the hydrophobic regions of surface glycoproteins HN and F, with binding energies ranging from −6.5 to −10.5 kcal/mol, while 50 ns molecular dynamics simulation confirmed complex stability. Laboratory testing using fluorescence-based neuraminidase assays demonstrated dose-dependent inhibitory activity with IC₅₀ values of 0.0043 ± 0.0015 mg/mL for filipin complex, 0.0117 ± 0.0029 mg/mL for nystatin, and 0.0220 ± 0.0138 mg/mL for natamycin, with similar ranking observed for fusion inhibition (EC₅₀ values of 0.00053 ± 0.00039, 0.00545 ± 0.00560, and 0.01196 ± 0.00965 mg/mL, respectively). While filipin complex exhibited the highest antiviral activity, its significant cytotoxicity limits therapeutic application, whereas natamycin demonstrated a favorable safety profile consistent with its GRAS status. These findings indicate that natamycin exhibits a favorable safety-to-efficacy profile in vitro, warranting further in vivo investigation to clarify its mechanism of action and establish practical application protocols for NDV control in poultry. Full article

Tumor cell migration relies on the integration of extracellular matrix (ECM) remodeling, cell surface signaling regulating cytoskeleton dynamics, and epithelial-to-mesenchymal transition (EMT). Clusterin (CLU), a secreted glycoprotein, is involved in extracellular proteostasis and is known to interact with members of the LDL receptor family, including low-density lipoprotein receptor-related protein 1 (LRP1). Beyond its canonical chaperone activity, CLU is involved in several biological processes, including cell survival, apoptosis, tissue remodeling, inflammation and cancer progression. On the other hand, the membrane type 1 matrix metalloproteinase (MT1-MMP), functionally linked to CD44 and LRP1, represents a key membrane-associated molecule that may control cell adhesion and receptor-mediated uptake of ECM ligands and proteases. In this article, we critically highlight a hypothetical model in which secreted CLU (sCLU) may function as the central player of a dynamic membrane-associated network integrating proteolysis, endocytosis, and intracellular signaling. Based on recent literature findings and STRING analyses, LRP1, MT1-MMP, CD44, and cell surface matrix components, such as proteoglycans (PGs) and integrins, are likely to be involved. By coordinating this membrane-associated molecular crosstalk, sCLU may integrate ECM remodeling with cytoskeletal dynamics and EMT-related programs related to invasive behavior. Overall, this framework highlights a potential mechanism through which sCLU may contribute to tumor cell plasticity and aggressiveness, suggesting new avenues for therapeutic intervention. Full article

Monkeypox virus, a zoonotic DNA virus belonging to the Orthopoxvirus genus, has emerged as a global health issue because of its fast spread to 104 nations over six continents. In the current study, an immunoinformatics pipeline was used to design a multiepitope-based prophylactic vaccine targeting the A35R glycoprotein and E8L membrane proteins of the monkeypox virus. Selected target proteins were surface-exposed, non-homologous to the human proteome, and essential for viral pathogenesis. B-cell and T-cell (MHC-I and MHC-II) epitopes with high antigenicity (>0.5), non-allergenicity, non-toxicity, and highly soluble in water with strong affinity towards innate and adaptive receptors, were prioritized. Shortlisted epitopes were combined to design the final vaccine utilizing an adjuvant (50S ribosomal L7/L12) and appropriate linkers for improved immunogenicity. Population coverage analysis showed wide HLA representation with 83.57% (MHC-I) and 88.8% (MHC-II) global coverage, including 89.6% for West Africa and 87.3% for Central Africa. Docking analysis of the vaccine construct with the TLR-4 receptor revealed stable interactions (−695.6 kcal/mol). Molecular dynamics simulations and binding free energies further confirmed structural stability. Immune simulations predicted strong activation of both humoral and cellular immune responses. These results indicate that the designed multiepitope vaccine construct is a viable option for additional experimental validation against the monkeypox virus. Full article

Early intervention is pivotal for mitigating the progression of Alzheimer’s disease (AD). This study presents an electrochemical immunosensor targeting synaptic vesicle glycoprotein 2A (SV2A) to facilitate early AD diagnosis. A sensing interface was engineered using a nanocomposite of graphene oxide (GO) and 3-carboxyl polypyrrole (3-COOH-PPy). Leveraging the synergistic effects between the large specific surface area of GO and the superior conductivity of 3-COOH-PPy, the composite established an efficient electron transport network. This architecture provided abundant active sites for capture antibody immobilization while significantly enhancing interfacial electron transfer kinetics. Coupling this interface with an enzyme-mediated signal amplification strategy based on the horseradish peroxidase (HRP)-catalyzed TMB/H₂O₂ system, the immunosensor achieved high sensitivity. It exhibited a wide linear range of 2 ng/mL to 16 μg/mL with a low limit of detection (LOD) of 0.15 ng/mL. Furthermore, successful detection in C57 mouse serum samples validated the method’s reliability and potential for clinical application. In conclusion, this immunosensor offers a sensitive and robust platform for the early diagnosis of AD. Full article

The porcine epidemic diarrhea virus (PEDV) causes a gastrointestinal disease generating mortality rates approaching 100% in piglets worldwide. The S glycoprotein of PEDV is the main target for the development of vaccines. Two vaccines approved by the Ministry of Agriculture and Rural Development are used in Mexico: the first vaccine is based on an inactivated virus isolated more than a decade ago, whereas the second vaccine is based on mRNA technology. The most important tool for controlling PEDV outbreaks is vaccination; however, coronaviruses are characterized by the accumulation of multiple mutations, which compromise the immune response elicited by outdated vaccines. In this work, we classified the Mexican strains of PEDV reported so far in GenBank, according to their genotypes. Subsequently, we searched for B and T cell epitopes conserved in Mexican PEDV strains using bioinformatic tools. In addition, we explored whether these epitopes can induce allergies, autoimmunity, and/or toxic effects. Next, we determined the localization of B cell epitopes in the S glycoprotein using the protein crystal and protein modeling of several S glycoproteins. Finally, we carried out molecular docking analysis to assess whether these T cell epitopes could interact with the peptide-binding groove of the Swine Leukocyte Antigens (SLAs). Five conserved B cell epitopes were found to be exposed on the surface of the S glycoprotein, whereas several promiscuous CTL and HTL epitopes were bound, with low free energy, to the peptide-binding grooves of SLA-I and SLA-II, respectively. The best epitopes were used to generate a plasmid carrying the sequence to produce a recombinant protein. This plasmid was used for transfection experiments in PK-15 cell culture. The B cell epitopes reported here were recognized by the sera from pigs infected with PEDV but not by the sera from uninfected animals. These results justify future evaluations of the ability of these epitopes to stimulate cytokine production by T cells, antibody generation, and their neutralizing activity. Full article

Background: Rheumatoid arthritis (RA) is a systemic, pro-inflammatory, autoimmune disease that mainly affects the joints in a symmetrical manner. Differential proteomic profiling through Sequential Window Acquisition of all Theoretical Fragment Ion Mass Spectra (SWATH-MS/MS) helps in a better understanding of the RA pathogenesis. In this study, we compared the differentially upregulated proteins with those associated with fibrosis to gain a deeper understanding of the fibrotic aspect of RA. Methods: We analyzed plasma proteomics data, previously obtained by SWATH-MS/MS. Our focus was on proteins associated with Leucine Rich Alpha2glycoprotein1 (LRG1) and we employed an in silico method. Results: We identified common proteins between RA and fibrosis. Among them, LRG1 and Serine Protease Inhibitor Clade A, Member 1 (SERPINA1) showed a high co-expression score in the gene clusters. LRG1 is both pro-inflammatory and pro-fibrotic, while SERPINA1 is an anti-inflammatory protein that inhibits pro-inflammatory and pro-fibrotic molecules (Elastase). Further, docking studies and a simulation study of the docked complexes with the analysis of Hydrogen bonds, Solvent Accessible Surface Area (SASA), Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) and Radius of gyration (Rg), suggested a strong interaction between the two partners, LRG1 and SERPINA1. Conclusions: Our study suggests that LRG1 may inhibit SERPINA1 and promote inflammation and fibrotic processes by disrupting SERPINA1’s primary function. Full article

Mucins are high-molecular-weight glycoproteins that form the main structural component of the mucus covering epithelial surfaces in the gastrointestinal, respiratory, and urogenital tracts. They support epithelial integrity by protecting against microbial invasion, dehydration, and mechanical or chemical insults, while facilitating the transit of luminal contents. Beyond their structural function, mucins play key roles in molecular recognition. Their extensive glycosylation enables interactions with a wide range of molecules and allows the discrimination between pathogenic and commensal microorganisms at mucosal surfaces. Mucins help maintain mucosal homeostasis by preventing pathogen adhesion and colonization, while simultaneously providing nutrients to commensal species, supporting their stability, and maintaining spatial segregation from epithelial surfaces. Aberrant expression of mucin subtypes or alterations in their glycosylation patterns are associated with numerous diseases, including a wide spectrum of cancers and inflammatory disorders. The immunological relevance of the esophageal mucosa has only recently been recognized. Advances in the study of the esophageal mucosa-associated immune surveillance system and its interactions with structural components of this organ’s surface, including mucins, have shed light on unique pathological processes in the esophagus, such as Barrett’s esophagus, gastroesophageal reflux disease, and eosinophilic esophagitis. This review focuses on the role of esophageal mucins in inflammation, compiling current evidence to provide an integrated overview of mucin-driven inflammatory mechanisms. Full article

Varicella-zoster virus (VZV) is a human neurotropic herpesvirus. The primary infection with VZV causes chickenpox and establishes latency in sensory and dorsal root ganglia. Viral reactivation leads to herpes zoster (HZ), which is accompanied by complications such as postherpetic neuralgia (PHN), causing a significant disease burden. At present, vaccination is the most effective preventive measure. We developed a recombinant zoster vaccine, gE/BFA01, which comprises truncated VZV glycoprotein E and the liposome-based adjuvant BFA01 (containing MPL and QS-21). In this study, we evaluated the recombinant zoster vaccine’s immunogenicity in a live attenuated VZV-primed C57BL/6N mouse model and explored the mechanism of action of the BFA01 adjuvant. The results indicate that the gE/BFA01 vaccine induces superior antibody responses and stronger cellular immune responses compared with gE with aluminum hydroxide. Furthermore, gE/BFA01 showed comparable immunogenicity to the licensed vaccine Shingrix. Mechanistic investigations revealed that the BFA01 adjuvant can enhance the recruitment of innate immune cells at the injection site, increase the expression of DCs surface maturation markers, and activate multiple inflammatory signaling pathways in lymph nodes. Collectively, these findings indicate that gE/BFA01 can induce potent humoral and cellular responses, supporting its further development as a high-efficiency vaccine candidate. Full article

The TEA domain (TEAD) transcription factors are important parts of the Hippo signaling cascade and are important therapeutic targets in cancer research because they help control cell growth, avoid apoptosis, and cause tumors to form. In this study, a structure-based virtual screening method was used to find new TEAD antagonists in the ChemDiv natural product database. Using the AutoDock platform for molecular docking, we ranked eight candidate ligands—16956, 726, 5271, 11768, 12384, 15598, 15641, and 3622—based on strong binding affinities, as shown by docking energies that ranged from −8.02 to −8.49 kcal/mol. Swiss ADME’s full in silico ADMET profile showed that all of the selected compounds had good pharmacokinetic properties and did not break Lipinski’s rule of five, which means they would be quite bioavailable when taken by mouth. Two lead candidates, 11768 and 15598, did not pass across the blood-brain barrier (BBB) and were not substrates for P-glycoprotein. This means that they had less exposure to the central nervous system and a lower chance of developing multidrug resistance. Later molecular dynamics (MD) simulations verified that the ligand TEAD complexes were stable in their shapes, and MMGBSA (Molecular Mechanics/Generalized Born Surface Area) free energy calculations indicated that they had high-affinity binding. Principal component analysis (PCA) and free energy landscape tests helped to explain even more the dynamic behavior and thermodynamic landscapes of the complexes. This integrated computational technique helped us find strong, drug-like TEAD inhibitors in a logical way. It also gave us a solid base for further preclinical testing and structural optimization in the creation of targeted anticancer drugs. Full article

YKL-40 is a glycoprotein that may be present at elevated levels in many cancers and neurodegenerative diseases. It has been investigated in numerous studies as a potential biomarker for several conditions, including Alzheimer’s Disease (AD). In this study, a biosensor with Surface Plasmon Resonance imaging (SPRi) detection, sensitive to YKL-40, was constructed for the detection of this analyte in the blood plasma of AD patients. Extensive validation of the biosensor was performed. This included the determination of analytical parameters such as the biosensor’s response characteristics, detection and quantification limits, precision, accuracy, repeatability, selectivity, stability, and performance in natural samples. Validation parameters were primarily tested using standard solutions, while natural samples were employed to evaluate repeatability, stability, and assay accuracy in three groups of samples from different patients. A YKL-40-specific antibody was used as the receptor layer, immobilized on a gold plate using the EDC/NHS protocol on thiol 11-MUA. The biosensor exhibited a wide operating range (1–200 ng/mL), a low detection limit (LOD) of 2 pg/mL, and a quantification limit (LOQ) of 7 pg/mL. High precision and accuracy were confirmed by the calculated standard deviations (SD) and coefficients of variation (CV), which ranged from 0.0009 to 7.02 ng/mL and from 0.12% to 9.24%, respectively. The sensor also demonstrated good repeatability (CV = 4.995%) and was capable of detecting the analyte of interest in complex biological matrices. Its applicability was confirmed in a study using plasma from AD patients and two selected control groups: plasma from smokers and patients with prostatitis. This allowed the assessment of YKL-40 levels across different groups. The results were consistent with literature values, and statistical analysis confirmed the significance of concentration differences between groups. Furthermore, ROC curve analysis confirmed the diagnostic usefulness of the constructed YKL-40 test in the context of Alzheimer’s disease. Full article

The glomalin-related soil protein (GRSP), a class of stable glycoproteins produced by arbuscular mycorrhizal fungi, constitute an important microbial-derived carbon pool in terrestrial ecosystems. However, the response of GRSP accumulation to land-use change and quantitative contribution to soil organic carbon (SOC) pools, as well as the environmental and edaphic factors controlling GRSP dynamics in different land-use systems, require further elucidation. To address these knowledge gaps, we systematically collected surface soil samples (0–20 cm depth) from 72 plots across three land-use types—tea plantations (TP; n = 24), artificial forests (AF; n = 24), and natural forests (NF; n = 24) in China’s Huangshan Mountain region between July and August 2024. GRSP was extracted via autoclaving (121 °C, 20 min) in 20 mM citrate buffer (pH 8.0), fractionated into total GRSP (T-GRSP), and quantified using the Bradford assay. Results revealed distinct patterns in soil carbon storage, with NF exhibiting the highest concentrations of both SOC (33.2 ± 8.69 g kg⁻¹) and total GRSP (T-GRSP: 2.64 ± 0.34 g kg⁻¹), followed by AF (SOC: 14.9 ± 2.55 g kg⁻¹; T-GRSP: 1.42 ± 0.25 g kg⁻¹) and TP (SOC: 7.07 ± 1.72 g kg⁻¹; T-GRSP: 0.58 ± 0.11 g kg⁻¹). Although absolute GRSP concentrations were lowest in TP, its proportional contribution to SOC remained consistent across land uses (TP: 8.72 ± 2.84%; AF: 9.69 ± 1.81%; NF: 8.40 ± 2.79%). Statistical analyses identified dissolved organic carbon and microbial biomass carbon as primary drivers of GRSP accumulation. Structural equation modeling further demonstrated that land-use type influenced SOC through its effects on MBC and fine-root biomass, which subsequently enhanced GRSP production. These findings demonstrate that undisturbed forest ecosystems enhance GRSP-mediated soil carbon sequestration, emphasizing the critical role of natural forest conservation in ecological sustainability. Full article