Search Results (677)

Lignocellulosic bio-based materials, such as wood, biocomposites, and natural fibers, exhibit desirable structural properties. This comprehensive review emphasizes the foundational and latest advancements in bioinspired improvement strategies, such as direct mineralization, biomineralization, lignocellulosic nanomaterials, protein-based treatments, and metal-chelating processes. Significant focus was placed on biomimetics, emulating natural protective mechanisms, with discussions on relevant topics including hierarchical mineral deposition, free-radical formation and quenching, and selective metal ion binding, and relating them to lignocellulosic bio-based material property improvements, particularly against fire and fungi. This review evaluates the effectiveness of different bioinspired processes: mineralized and biomineralized composites improve thermal stability, nanocellulose and lignin nanoparticles provide physical, thermal, and chemical barriers, proteins offer biochemical inhibition and mineral templating, and chelators interfere with fungal oxidative pathways while simultaneously improving fire retardancy through selective binding with metal ions. Synergistic approaches integrating various mechanisms could potentially lead to long-lasting and multifunctional protection. This review also highlights the research gaps, challenges, and potential for future applications. Full article

Alzheimer’s disease (AD) remains an unmet medical challenge, as there are no effective therapies that alter the disease’s progression. While approaches have targeted molecules like acetylcholine (ACh) and glutamate, these strategies have provided only limited benefits and do not address the complex molecular mechanisms underlying AD development. This review suggests that β-alanine (3-aminopropanoic acid) is an underexplored neurotransmitter that could serve as a potential AD drug target. Existing evidence indicates that β-alanine modulates GABAergic and glutamatergic neurotransmission, thereby affecting neuronal hyperexcitability. Additionally, studies suggest that β-alanine has antioxidant effects, reducing oxidative stress caused by reactive oxygen species (ROS). We propose that β-alanine might bind to Aβ/tau proteins, possibly targeting the six-amino acid sequences EVHHQK/DDKKAK, which are involved in protein aggregation. β-Alanine may also influence the release of pro-inflammatory cytokines from microglia, potentially reducing neuroinflammation. We also hypothesize that β-alanine may help regulate metal dyshomeostasis, which leads to ROS production. Taurine, structurally like β-alanine, appears to influence comparable mechanisms. Although structural similarity doesn’t ensure therapeutic effectiveness, this evidence supports considering β-alanine as a treatment for AD. Furthermore, β-alanine and its analogues face challenges, including crossing the blood–brain barrier (BBB) and optimizing structure–activity relationships (SAR). This review includes articles through September 2025, sourced from four databases. Full article

Metal nanoparticles (NP) are increasingly used in biomedical applications. Among them, silver NPs (AgNPs) are used as active components in antibacterial coatings for wound dressings, medical devices, implants, cosmetics, textiles, and food packaging. On the other hand, AgNPs can be toxic to humans, depending on the dose and route of exposure, as agents delivering silver to cells. The cysteine residues are the primary molecular targets in such exposures, due to the high affinity of Ag⁺ ions to thiol groups. The Endothelial monocyte-activating polypeptide II (EMAP II), a cleaved C-terminal peptide of the intracellular aminoacyl-tRNA synthetase multifunctional protein AIMP1, contains five cysteines exposed at its surface. This prompted the question of whether they can be targeted by Ag⁺ ions present at the AgNPs surface or released from AgNPs in the course of oxidative metabolism of the cell. We explored the interactions between recombinant EMAP II, tRNA, and AgNPs using UV-Vis and fluorescence spectroscopy, providing insight into the effects of AgNPs dissolution kinetics on interaction EMAP II with tRNA. In addition, the EMAP II fragments binding to intact AgNPs were established by heteronuclear ¹H-¹⁵N HSQC spectra utilizing a paramagnetic probe. Structural analysis of the EMAP II reveal that the 3D structure of protein was destabilized (partially denatured) by the binding of Ag⁺ ions released from AgNPs at the most exposed cysteines. Surprisingly, this effect enhanced tRNA affinity to EMAP II, lowering its $K_d$. The course of the EMAP II/tRNA/AgNP reaction was also modulated by other factors, such as the presence of Mg²⁺ ions and TCEP, a thiol-group protector used to mimic the reducing conditions of the cell. Full article

The interaction of metals with serum γ-globulins is of particular interest, as it can modulate immune system function and lead to unforeseen consequences following the intake of metal ions or their complexes, which are often considered (pro)drugs. This paper focuses on the interactions between gold(III) species and bovine or human serum γ-globulins in aqueous solutions. Using UV-Vis, fluorescence, and CD (circular dichroism) spectroscopy in diluted or 0.1 M NaCl aqueous solutions, we determined the most probable stoichiometry of the gold(III)-protein associates and their conditional binding constants. On average, 13 to 19 gold atoms bind per protein molecule, depending on the medium and protein origin, with apparent binding constants ranging from 3.6 to 4.6 (log K values; hydroxyl-containing complexes exhibit lower binding affinity). CD spectra revealed no changes in protein secondary structure induced by the increase in electrolyte concentration. However, the addition of gold(III) species resulted in a decrease in β-sheet content and a corresponding increase in turns or disordered fragments. Full article

The urgent need for effective therapies against cancer and antimicrobial-resistant pathogens motivates the development of novel metal-based complexes. Herein, we report the synthesis and characterization of four novel cobalt(II) complexes with biologically relevant β-diketo ester ligands. The complexes were characterized via UV-Vis, FTIR, mass spectrometry, and elemental analysis. Their biological activities were evaluated through antimicrobial and cytotoxic assays. Complex B1 exhibited the strongest antimicrobial activity, with minimum inhibitory concentrations (MICs) of 0.23 mg/mL against Staphylococcus aureus and Proteus mirabilis, and 0.01 mg/mL against Mucor mucedo, exceeding the performance of ketoconazole. Cytotoxicity studies on SW480 colorectal cancer cells and HaCaT normal keratinocytes identified B3 as the most potent anticancer agent (IC₅₀ = 11.49 µM), selectively targeting tumor cells. Morphological analysis indicated apoptosis as the primary mode of cell death. Mechanistic studies were performed to elucidate interactions with biomolecules. UV-Vis and fluorescence spectroscopy, viscosity measurements, and molecular docking revealed that B3 binds strongly to calf thymus DNA via hydrophobic interactions and groove binding, and exhibits selective binding to bovine serum albumin (site II, subdomain IIIA). These results highlight the potential of cobalt(II) complexes as multifunctional agents with significant antimicrobial and antitumor activities and provide detailed insight into their molecular interactions with DNA and serum proteins. Full article

The genus Hyotissa (family Gryphaeidae) comprises ecologically and economically important marine bivalves, yet their molecular biology remains poorly characterized. This study presents de novo transcriptome sequencing of three Hyotissa species—H. sinensis, H. inaequivalvis, and Hyotissa sp.—to systematically identify and characterize the superoxide dismutase (SOD) gene family, a crucial component of the antioxidant defense system. We identified 46 SOD genes, including both Cu/Zn-SOD and Fe/Mn-SOD types, which exhibited considerable variation in molecular properties, domain architecture, and potential phosphorylation sites. Phylogenetic analysis revealed both evolutionary conservation and diversification of SODs across species. Notably, we identified homologs of two specialized SOD types: Dominin, which showed mutations in metal-binding sites suggestive of functional divergence, and copper-only SOD repeat proteins (CSRPs), which retained copper-binding residues but lost zinc-binding capacity. These findings suggest that the SOD family in Hyotissa has undergone significant functional diversification, potentially as an adaptive response to their high-oxygen, high-ultraviolet reef habitats. This study provides foundational transcriptomic resources for Hyotissa and offers new insights into the evolution and environmental adaptation of SOD genes in marine bivalves. Full article

Human serum albumin (HSA) is one of the main proteins in human blood plasma and serves as a molecular “taxi” transporting various compounds, including organic compounds, drugs, metal ions, etc., through the circulatory system throughout the human body. As with any other proteins, HSA hydration plays an important role in maintaining its structure and functioning as well as influencing its ability to bind to ligands. This contribution presents, for the first time, a generalized picture of hydration of this biomacromolecule obtained within the framework of the 3D-RISM (three-dimensional Reference Interaction Site Model) theory of solvation. Based on 3D isodensity maps and structural parameters (hydration numbers, hydration layer thickness, fraction of hydrogen bonds, SASA, etc.), the most probable model of HSA hydration structure was reconstructed. With the description of HSA hydration, two important issues were also addressed in detail. The first is the correct determination of the hydration layer thickness, a common problem in protein science. The second is the possible state and behavior of hydration water in HSA–ligand binding. The presented results provide a deeper understanding of the relationship between solvent and HSA, which brings new knowledge to the understanding of protein hydration. Full article

Two endogenous peptides, β-alanyl-L-histidine, named carnosine (Car), and glycyl-L-histidyl-L-lysine (GHK), derived from the matricellular protein Secreted Protein Acidic and Rich in Cysteine (SPARC), share many beneficial functions. The hydrolytic enzyme carnosinase for Car and the low stability for GHK can put into question their antioxidant, antiaggregating, and anti-inflammatory properties. The glycoconjugates of Car with a di- (trehalose, Tre) or polysaccharide (hyaluronan, HA) inhibit carnosinase, while the synthesis of HAGHK derivatives increases the tripeptide stability and protects/delays the biopolymer degradation. A synergic effect between the two components of the glycoconjugates is evident in their consequently preserved protective features. TreCar, HACar, and HAGHK maintain the copper-binding ability of the peptides alone, and the saccharides potentiate the Cu,Zn-superoxide dismutase-like ability of the copper(II) complexes with the glycoconjugates. These peptide derivatives behave as copper ionophores, utilizing Cu²⁺ present in the culture medium; also, an increase in the metal intracellular level occurs with a consequent stimulation of the copper-driven signaling pathways that produce the expression/release of trophic (Brain-Derived Neurotrophic Factor, BDNF, and Bone Morphogenetic Protein 2, BMP-2) and angiogenic (Vascular Endothelial Growth Factor, VEGF) proteins. Copper chaperons for SOD1, CCS, and Antioxidant 1 (Atox-1) are the copper chaperones that act as transcription factors. Full article

The global food supply is increasingly challenged by toxicologically relevant natural and synthetic chemicals, including mycotoxins, pesticides, heavy metals, and migrants from food packaging. Conventional physical and chemical detoxification approaches can reduce contaminant loads but may compromise nutritional and sensory quality or leave residues, motivating a shift toward biological strategies. This review synthesizes current evidence on Saccharomyces cerevisiae var. boulardii, a clinically established probiotic yeast, as a multifaceted biological detoxification agent in foods. We outline its dual modes of action: (i) rapid, reversible adsorption of contaminants mediated by the architecture of the yeast cell wall (β glucans, mannans, chitin), and (ii) active biotransformation through secreted proteins and enzymes. S. cerevisiae var. boulardii has been reported to remove up to 96.9% of aflatoxin M₁ in reconstituted milk, depending on strain, dose, contact time, pH, and matrix effects. We collate findings for other contaminant classes and highlight practical variables that govern efficacy, while comparing detoxification performance with bacterial probiotics and conventional methods. Critical knowledge gaps were highlighted, including standardized testing protocols, mechanistic resolution of adsorption versus degradation, stability and regeneration of binding capacity, sensory impacts, with scale up and regulatory pathways. A roadmap is proposed to harmonize methods and unlock the full potential of this promising biotherapeutic yeast for food safety applications. Full article

Polyethylene terephthalate-derived fluorescent carbon quantum dots (PET-CQDs) are promising nanomaterials for sensing and biomedical uses, yet their biological interactions after metal doping require careful evaluation. Here, we report an in silico assessment of pristine and dual-site (via graphitic [G] and carbonyl [O]) metal-doped PET-CQDs (Ca, Mg, Fe, Zn) using molecular docking against eight human proteins: HSA (distribution), CYP3A4 (metabolism), hemoglobin (systemic biocompatibility), transferrin (uptake), GST (detoxification), ERα (endocrine regulation), IL-6 (inflammation), and caspase-3 (cytotoxic signaling) together with ADMET profiling and DFT–docking correlation analysis. Docking affinities were compared with controls and ranged from −7.8 to −10.4 kcal·mol⁻¹ across systems, with binding stabilized by π–π stacking, hydrogen bonding and metal–ligand coordination involving residues such as arginine, tyrosine and serine. Importantly, top-performing CQD variants differed by target: PET-CQDs, MgG_PET-CQDs and FeG_PET-CQDs were best for GST; ERα interacted favorably with all doped variants; IL-6 bound best to CaO_PET-CQDs and FeO_PET-CQDs (≈−7.1 kcal·mol⁻¹); HSA favored CaG_PET-CQDs (−10.0 kcal·mol⁻¹) and FeO_PET-CQDs (−9.9 kcal·mol⁻¹); CYP3A4 bound most strongly to pristine PET-CQDs; hemoglobin favored MgG_PET-CQDs (−9.6 kcal·mol⁻¹) and FeO_PET-CQDs (−9.3 kcal·mol⁻¹); transferrin favored FeG_PET-CQDs; caspase-3 showed favored binding overall (pristine −6.8 kcal·mol⁻¹; doped −7.4 to −7.6 kcal·mol⁻¹). ADMET predictions indicated high GI absorption, improved aqueous solubility for some dopants (~18.6 mg·mL⁻¹ for Ca-O/Mg-O), low skin permeability and no mutagenic/carcinogenic flags. Regression analysis showed frontier orbital descriptors (HOMO/LUMO) partially explain selective affinities for ERα and IL-6. These results support a target-guided selection of PET-CQDs for biomedical applications, and they call for experimental validation of selected dopant–target pairs. Full article

Among the microorganisms present in the microbiome of Camellia japonica flowers, extracellular vesicles (EVs) derived from Leuconostoc mesenteroides were isolated to investigate their modulatory effects on moisturizing and barrier-related molecular markers. To identify the function of major proteins in L. mesenteroides DB-21-derived extracellular vesicles (LEVs), Gene Ontology (GO) analysis was performed, revealing ATP binding, ribosomal structural proteins, and metal ion binding as predominant molecular-function categories. These proteomic characteristics provide a molecular context that supports the interpretation of the moisturizing and barrier-related responses observed in this study. To further verify new findings, we performed functional evaluations using in vitro and 3D skin models. LEVs increased the mRNA expression level of HAS3, which encodes hyaluronic acid synthase. In addition, the expression levels of filaggrin and involucrin, key proteins involved in skin barrier formation, increased, and these markers were determined a concentration-dependent increase in a 3D artificial skin model. Also, we confirmed that the expression levels of filaggrin and involucrin, which were reduced by UVB damage, were restored when LEVs were applied. In conclusion, LEVs are effective in enhancing various molecular markers related to the skin barrier function, and these results reveal that they hold promise as next-generation microbiome-based functional ingredients. Full article

A novel heavy metal-resistant bacterium with significant bioremediation capabilities, Sinirhodobacter sp. 1C5-22 was isolated from moderately polluted Shenzhen Futian mangrove rhizosphere sediments. This strain showed exceptional tolerance (MIC ≥ 600 mg/L for Cu/Zn; > 500 mg/L for Ni). Analyses revealed distinct metal-specific distribution strategies: Cd and Ni were predominantly bound extracellularly (>80%); Cu was bound intracellularly (~60%); and Zn exhibited balanced partitioning. Integrated omics analysis identified a molecular defense mechanism coordinated by the CreB transcriptional regulator. This Adsorption–Sequestration–Efflux (ASE) system integrates extracellular polymer binding, periplasmic sequestration via stable metal-binding proteins, and efflux pump activity, resolving the apparent adsorption-tolerance paradox at elevated concentrations. For bioremediation applications, we developed a polyvinyl alcohol–sodium alginate immobilized consortium (PVA-SA 1C5-22). The engineered agent displayed significantly enhanced biosorption capacity compared to free cells and effectively mitigated heavy metal-induced oxidative damage, evidenced by stabilized malondialdehyde levels. It demonstrated robust reusability, maintaining high metal enrichment across five adsorption–desorption cycles in multi-metal wastewater with efficient HCl-driven desorption (55–70%). Critically, it achieved stable nickel removal performance (~20% adsorption, >50% desorption) from authentic electroplating wastewater (1850 mg/L Ni²⁺) through successive multiple cycles. Our integrated approach bridges microbial ecology and environmental biotechnology, establishing this immobilized system as a highly sustainable strategy for complex industrial effluent remediation. Full article

Plant–microbe interactions exert a significant influence on host stress responses; however, the molecular mechanisms underlying these effects remain inadequately understood. In this study, we characterize FaMAN8, an α-mannosidase from Fragaria × ananassa, to explore its role in adaptation to heat waves and water deficit, as well as its modulation by fungal endophytes. Transcriptomic analysis identified FaMAN8 as the sole α-mannosidase isoform highly conserved across reported sequences, with root-specific induction under conditions of heat stress, deficient irrigation, and endophytic colonization. Structural modeling revealed that FaMAN8 exhibits the canonical domain organization of glycoside hydrolase family 38 (GH38) enzymes, featuring a conserved catalytic architecture and metal-binding site. Molecular docking and dynamics simulations with the Man₃GlcNAc₂ ligand indicated a stable binding pocket involving key catalytic residues and strong electrostatic complementarity. MM-GBSA and free energy landscape analyses further supported the thermodynamic stability of the protein–ligand complex. Cavity analysis revealed a larger active site in FaMAN8 compared to its homolog JbMAN, suggesting broader substrate accommodation. Collectively, these findings identify FaMAN8 as a stress-responsive glycosidase potentially involved in glycan remodeling during beneficial root–fungus interactions. This work provides molecular insights into plant–microbe symbiosis and lays the groundwork for microbiome-informed strategies to enhance crop stress resilience. Full article

N-tetradecanoyl-L-homoserine lactone (C₁₄-HSL) is a long-chain signaling molecule belonging to acyl-homoserine lactones (AHLs), which is widely present in the quorum sensing (QS) system of Gram-negative bacteria. In this study, the effects of C₁₄-HSL on chalcopyrite bioleaching mediated by Acidithiobacillus ferrooxidans (A. ferrooxidans) were investigated. After cultivating A. ferrooxidans with different energy substrates and exploring the potential mechanisms of signal molecule production, chalcopyrite was selected as the energy substrate for further study. Molecular docking analysis revealed that the high binding affinity between AHL and the receptor protein AfeR in A. ferrooxidans was beneficial for the activation of transcription by the AfeR-AHL complex, promoting their biological impact. The variations in the physicochemical parameters of pH, redox potential, and copper ions revealed that after adding C₁₄-HSL, the leaching rate of chalcopyrite increased (1.15 times during the initial 12 days). Further analysis of the mechanism of extracellular polymers formation indicated that the presence of C₁₄-HSL could promote the formation of biofilms and the adhesion of bacteria, facilitating mineral leaching rate of A. ferrooxidans. This research provides a theoretical basis for regulating the biological leaching process of chalcopyrite and metal recovery using signaling molecules, which could also be used to control environmental damage caused by acid mine/rock drainage. Full article

Among many metal ions in biological systems, iron plays a fundamental role. Transferrins are iron-binding glycoproteins responsible for transporting Fe³⁺ in vertebrate blood. Neisseria meningitidis, a Gram-negative pathogen causing meningitis, relies on iron for survival and acquires it from human transferrin (hTf) using two surface proteins, TbpA and TbpB. These proteins interact with hTf to form a ternary TbpA–TbpB–hTf complex, enabling iron capture from the host. The absence of an experimental crystal structure for this complex has hindered computational studies, a detailed understanding of Fe³⁺ dissociation, and designing efficient therapeutics. This study presents the first computational model of the ternary complex, its validation, and molecular dynamics simulations. Structural analyses revealed key electrostatic interactions regulating Fe³⁺ coordination and essential contact regions between proteins. The role of Lys359 from TbpA was investigated via QM/MM calculations by evaluating Fe³⁺ binding energies of isolated hTf, the ternary complex, and Lys359Ala, Lys359Arg, Lys359Asp mutant models. Results revealed that the proton transfer from Lys359 leads to disruption of Tyr517–Fe³⁺ coordination, facilitating iron transfer to the bacterial system. Natural bond orbital analysis confirmed this mechanism. The findings provide new molecular insight into N. meningitidis iron acquisition and identify Lys359 as a potential target for covalent inhibitor design, guiding the development of novel therapeutics against meningococcal infection. Full article