Search Results (190)

This study investigated the effects of Auricularia auricula Polysaccharide (AAP) concentrations on the rheological and thermal properties of gluten and its subunit components. We used multiple techniques, including dynamic rheology, differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), free thiol group analysis, and scanning electron microscopy (SEM). The results revealed that AAP increased the storage (G′) and loss (G″) modulus of gluten, glutenin, and gliadin, promoting compact elastic protein networks. DSC and free thiol group analysis demonstrated that AAP enhanced thermal stability and disulfide bond cross-linking in gluten and glutenin, but reduced thermostability and inhibited disulfide formation in gliadin. Secondary structure analysis showed 31.93% and 17.72% increases in α-helix and β-sheet content, respectively, in glutenin at 8% AAP, thereby enhancing the orderliness of the gluten structure and improving structural rigidity, while reducing gliadin’s structural order. Microscopy confirmed AAP narrowed gluten matrix pores, forming uniform honeycomb structures (though high concentrations caused disruption). In summary, AAP primarily stabilizes gluten conformation by modulating glutenin structure, thereby enhancing rheological and thermal properties. Full article

Plant-based meat analogs, particularly those produced by high-moisture extrusion, are prone to quality deterioration during frozen storage due to poor freeze–thaw stability. This study aimed to develop a synergistic stabilization strategy for soy protein isolate (SPI)-based extrudates using glucose oxidase (GO), phytase (PA), and tamarind gum (TG). The effects of individual additives (GO, PA, TG) and their combination (GO + TG) were systematically evaluated over seven freeze–thaw cycles, with a pure soybean-protein meat analog (PSM) as a control. The results showed that repeated freeze–thaw cycles severely degraded the control groups, leading to reduced water-holding capacity (WHC), increased hardness, and color darkening. While all additives mitigated these changes, the GO + TG combination exhibited the most pronounced protective effect, maintaining the highest WHC (0.993 ± 0.000), optimal texture (hardness 66.0 ± 0.0 N, elasticity 3.7 ± 0.0 mm), and minimal color variation. Structural analyses revealed that GO + TG effectively suppressed protein oxidation, minimized sulfhydryl loss, preserved protein secondary and tertiary structures, and inhibited the conversion of immobilized water to free water. The synergistic mechanism is attributed to the formation of a dual-network structure, wherein GO enhances covalent cross-linking and TG provides steric stabilization. This study offers a practical and effective approach for enhancing the freeze–thaw stability of extruded plant-based meat products, with potential industrial applications. Full article

p17, the human immunodeficiency virus type 1 (HIV-1) matrix protein traditionally associated with viral assembly, has been recently investigated for its extracellular functions linked to vascular damage. This review examines the molecular and pathogenic signatures by which p17 and its variants (vp17s) contribute to endothelial activation, aberrant angiogenesis, and vascular inflammation, highlighting their relevance even under effective antiretroviral therapy (ART). Specifically, p17 exerts chemokine-like activities by binding to chemokine (C-X-C motif) receptor-1 and 2 (CXCR-1/2) on endothelial cells (ECs). This interaction triggers key signaling cascades, including the protein kinase B (Akt)-dependent extracellular signal-regulated kinase (ERK) pathway and endothelin-1/endothelin receptor B axis, driving EC motility, capillary formation, and lymphangiogenesis. Variants such as S75X demonstrate enhanced lymphangiogenic potency, associating them with tumorigenic processes involved in non-Hodgkin lymphoma (NHL) pathogenesis. Importantly, p17 promotes endothelial von Willebrand factor (vWF) storage and secretion, implicating a pro-coagulant state that may trigger the increased thromboembolic risks observed in HIV-positive patients. Furthermore, p17 crosses the blood–brain barrier (BBB) via CXCR-2-mediated pathways, contributing to neuroinflammation by activating microglia and astrocytes and amplifying monocyte chemoattractant protein-1 (MCP-1) levels, therefore playing a critical role in the development of HIV-associated neurocognitive disorders. Hence, the elaboration of potential therapeutic strategies finalized at inhibiting p17/vp17s’ interaction with their receptors could complement ART by addressing HIV-related neurovascular morbidity. Full article

A series of azide- and cyclooctyne-functionalized N-hydroxysuccinimidyl esters (NHS esters) and benzotriazolides were prepared and used as N-acylation reagents to obtain azide-(BSA-1) and cyclooctyne-functionalized bovine serum albumin proteins (BSA-2), fluorescein derivatives 5 and 6, and homobifunctional linkers 3 and 4. Strain-promoted azide-alkyne cycloaddition (SPAAC) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of azide-functionalized fluorescent probe 5 and alkyne-functionalized fluorescent probe 6 with complementary functionalized proteins BSA-2 and BSA-1 yielded fluorescent cycloadducts BSA-2-5 and BSA-1-6. These cycloadducts were used to determine the loading of BSA-1 and BSA-2 with the respective azido and cyclooctyne groups based on their molar absorbances and fluorescence intensities. Dimerization through covalent cross-linking of BSA was then performed by SPAAC between azide-functionalized BSA-1 and cyclooctyne-functionalized BSA-2, and by treating BSA-1 and BSA-2 with 0.5 equiv. of complementary bis-cyclooctyne linker 4 and bis-azide linker 3. Although the formation of covalent dimers BSA-1-2-BSA, BSA-1-6-1-BSA, and BSA-2-5-2-BSA was detected by SDS-PAGE analysis, this was a minor process, and most of the functionalized BSA did not form covalent dimers. Full article

This review article focuses first on the historical development of present understanding of gap junction channel architecture, one of its goals being to enlighten younger generations of scientists about the early steps of this field that begun over half a century ago. Early findings on gap junction architecture are reviewed as follows. The channels cross the membrane and project from the membrane surfaces; they are made of six subunits (hexamers) and show dimples on both ends, which represent inner and outer openings of the channel. Images of the central dimples on both channel ends (channel pores) seen in freeze-fracture replicas correspond to the electron-opaque spots visible in negatively stained sections and in isolated junctions. The channels are linked to each other extracellularly. Calmodulin (CaM) is a major accessory protein of gap junctions that is involved in channel gating and gap junction formation and is also likely to play a key role in determining different patterns of channel aggregation. Full article

Amyloid fibrillization represents an effective strategy for extending and enhancing protein function, particularly for the delivery of hydrophobic active substances. In this study, oat globulin (OG) and its fibrils were complexed with quercetin (Que) to construct the delivery system, and ultrasonic pretreatment was applied during fibril preparation to explore the promoter of complex formation. The results demonstrated that complexation with Que induced a dose-dependent static quenching of the intrinsic fluorescence of the protein/fibrils, with hydrophobic interactions and tryptophan residues being the primary interaction forces and the main fluorescence quenching groups, respectively. In comparison, OG fibrils prepared with ultrasound pretreatment (UOGF) exhibited the strongest encapsulation and loading capacity for Que, ranging from 97.16% at a mass ratio of 200:1 to 42.48% at a ratio of 25:1. Subsequently, complexes were prepared with a ratio of 50:1. Structural analysis revealed that Que primarily interacts with the protein/fibril carriers through hydrogen bonds and hydrophobic interactions, inducing structural changes and ultimately being encapsulated in an amorphous form within the composite material. Additionally, Que promoted the mutual aggregation and cross-linking of protein/fibril units, leading to increased hydrodynamic diameter and zeta-potential. Moreover, UOGF-Que showed the greatest improvement in the thermal stability and the photostability of Que, and enhancing the bioaccessibility. These findings provide valuable insights into using ultrasound as an auxiliary measure for fibril self-assembly to enhance the application potential of fibrils, especially the delivery of hydrophobic functional substances. Full article

Background: Renal stone disease is a common urological condition considered to be greatly affected by lifestyle, dietary practices, and hydration status. With the rapid advancement and remarkable rise in digital communication, social media has become an important source of health information. However, little is known about its effects on raising public awareness of dietary and fluid-related risk factors for kidney stone formation, particularly in Middle Eastern populations. Aim: We aimed to evaluate the impact of social media platforms on public awareness of dietary habits and fluid consumption in relation to kidney stone prevention. Methods: A cross-sectional survey was applied to 980 adults with varying demographic characteristics. Data on social media use, dietary and fluid knowledge, and attitudes toward kidney stone prevention were collected through structured questionnaires. Statistical analyses, including regression and mediation models, were employed to identify predictors of awareness and explore pathways linking social media use to knowledge and attitudes. Results: Among the 980 participants (mean age = 29.9 ± 11 years; 55.4% males), 69.9% held university degrees, and 7.2% had a history of kidney stones. The overall awareness of kidney stone prevention varied, with most of the participants recognizing the protective role of adequate hydration (67%) and the adverse impact of soft-drink consumption (73.2%), while knowledge of dietary contributors such as animal protein and tea was limited. Greater knowledge and more appropriate attitudes were associated with older age, female gender, following healthcare professionals, and engagement with medical websites, YouTube, and TikTok. Mediation analysis revealed that social media influenced awareness indirectly through improvements in knowledge and attitudes. Conclusions: This study reveals that the digital environment shapes both public knowledge of and attitudes toward kidney stone prevention, though critical knowledge gaps persist regarding complex dietary factors. Mediation analysis indicated that the digital influence is likely channeled through improvements in knowledge and attitudes. We emphasize that source credibility is paramount; relying on official medical websites and following health professionals were the most effective strategies for boosting awareness. Therefore, expert-led educational strategies must be integrated into public health protocols. Full article

Extracellular particles (EPs), an umbrella term encompassing membrane-enclosed extracellular vesicles (EVs) and non-vesicular extracellular particles ([NVEPs], previously described as extracellular condensates [ECs]) contain a complex cargo of biomolecules, including DNA, RNA, proteins, and lipids, reflecting the physiological state of their cell of origin. Identifying proteins associated with EPs that regulate host responses to physiological and pathophysiological processes is of critical importance. Here, we report the findings of our study to gain insight into the proteins associated with NVEPs. We used samples from human semen, the rat brain, and the rhesus macaque (RM) brain and blood to assess the physical properties and proteome profiles of NVEPs from these specimens. The results show significant differences in the zeta potential, concentration, and size of NVEPs across different species. We identified 938, 51, and 509 total proteins from NVEPs isolated from rat brain tissues, RM blood, and human seminal plasma, respectively. The species-specific protein networks show distinct biological themes, while the species-conserved protein interactome was identified with six proteins (ALB, CST3, FIBA/FGA, GSTP1, PLMN/PLG, PPIA) associated with NVEPs in all samples. The six NVEP-associated proteins are prone to aggregation and formation of wide, insoluble, unbranched filaments with a cross-beta sheet quaternary structure, such as amyloid fibrils. Protein-to-function analysis indicates that the six identified proteins are linked to the release of dopamine, immune-mediated inflammatory disease, replication of RNA viruses, HIV-HCV co-infection, and inflammation. These interesting findings have created an opportunity to evaluate NVEPs for their potential use as biomarkers of health and disease. Additional in-depth studies are needed to clarify when and how these proteins sustain their physiological role or transition to pathogenic roles. Full article

In this study, the insufficient ability of tartary buckwheat protein (TBP) to stabilize Pickering emulsions was addressed by preparing TBP–sodium alginate (SA) composite particles via cross-linking and systematic optimization of the preparation parameters. The results showed that at a pH of 9.0 with 1.0% (w/v) TBP and 0.2% (w/v) SA, the zeta potential of the prepared TBP–SA composite particles was significantly more negative, and the particle size was significantly larger, than those of TBP, while emulsifying activity index and emulsifying stability index increased to 53.76 m²/g and 78.78%, respectively. Scanning electron microscopy confirmed the formation of a dense network structure; differential scanning calorimetry revealed a thermal denaturation temperature of 83 °C. Fourier transform infrared spectroscopy and surface hydrophobicity results indicated that the complex was formed primarily through hydrogen bonding and hydrophobic interactions between TBP and SA, which induced conformational changes in the protein. The Pickering emulsion prepared with 5% (w/v) TBP–SA composite particles and 60% (φ) oil phase was stable during 4-month storage, at a high temperature of 75 °C, high salt conditions of 600 mM, and pH of 3.0–9.0. The stabilization mechanisms may involve: (1) strong electrostatic repulsion provided by the highly negative zeta potential; (2) steric hindrance and mechanical strength imparted by the dense interfacial network; and (3) restriction of droplet mobility due to SA-induced gelation. Full article

Background: Pseudorabies virus (PRV), a critical porcine herpesvirus, induces severe diseases in both livestock and wildlife, imposing an incalculable burden and economic losses in livestock production. In this study, we investigated the evolutionary mechanisms and host adaptation strategies of the PRV gB gene through genomic alignment. The gB gene is highly conserved in PRV, and its encoded gB protein exhibits functional interchangeability across different herpesvirus species. Notably, the gB protein elicits the production of both complement-dependent and complement-independent neutralizing antibodies in animals, while also being closely associated with syncytium formation. Methods: Phylogenetic analysis and codon usage pattern analysis were performed in this study. A total of 110 gB gene sequences were analyzed, which were collected from [2011 to 2024] across the following regions: [Fujian, Shanxi, Guangxi, Guangdong, Chongqing, Henan, Shaanxi, Heilongjiang, Sichuan, Jiangsu, Jilin, Huzhou, Shandong, Hubei, Jiangxi, Beijing, Shanghai, Chengdu (China)], [Budapest, Szeged (Hungary)], [Tokyo (Japan)], [London (United Kingdom)], [Athens (Greece)], [Berlin (Germany)], and [New Jersey (United States)]. Results: The gB gene of PRV employs an evolutionary “selective optimization” strategy to maintain a dynamic balance between ensuring functional expression and evading host immune pressure, with this core trend strongly supported by its codon usage bias and mutation characteristics. First, the gene exhibits significant codon usage bias [Effective Number of Codons (ENC) = 27.94 ± 0.1528], driven primarily by natural selection rather than mere mutational pressure. Second, phylogenetic analysis shows that the second codon position of gB has the highest mutation rate (1.0586)—a feature closely linked to its antigenic variation and immune escape capabilities, further reflecting adaptive evolution against host immune pressure. Additionally, ENC-GC3 plot analysis reveals the complex regulatory mechanisms underlying codon bias formation, providing molecular evidence for the “selective optimization” strategy and clarifying PRV’s core evolutionary path to balance functional needs and immune pressure over time. Conclusions: Our study findings deepen our understanding of the evolutionary mechanisms of PRV and provide theoretical support for designing vaccines and assessing the risk of cross-species transmission. Full article

Approximately half of the world population is infected with the human pathogen Helicobacter pylori, which causes gastric inflammation, chronic gastritis, or peptide ulceration. A significant factor in the colonization of the upper digestive system is the helical shape of H. pylori. This helical form is maintained by a complex network of peptidoglycan (PG)-modifying enzymes and cytoskeletal proteins. Among these, the D,D-endopeptidase Csd2 plays a central role, working in conjunction with other cell shape-determining (Csd) proteins. Csd1 and Csd2 have been categorized as members of the M23B metallopeptidase family. These enzymes are classified as D,D-endopeptidases, and their function involves the cleavage of the D-Ala4-mDAP3 bond, which is present in the cross-linked di-mer muropeptides. Despite the fact that the structure of the Csd1:Csd2 complex has been examined via biochemical methods, information on the in vivo localization and dynamics of D,D-endopeptidases is still missing. Here, we use an approach that employs sophisticated different microscopy methods to visualize the spatial temporal localization and dynamics of Csd2, involving both structured illumination microscopy and single-molecule tracking. Our findings thus contribute to refining the existing model for this cellular complex by revealing curvature-dependent spatial organization and temporal dynamics underlying peptidoglycan remodeling processes essential for helical cell shape formation and maintenance. Understanding the dynamics provides insight into the mechanisms that maintain bacterial morphology and potential targets for therapeutic intervention. Full article

H5N1 Influenza A virus continues to pose a significant zoonotic threat, with increasing evidence of interspecies transmission and genetic adaptation. Previous studies primarily focused on avian or human isolates, with limited comprehensive analysis of H5N1 evolution across multiple mammalian hosts. Existing molecular surveillance often lags behind viral evolution; this study underscores the necessity for real-time monitoring of ongoing mutations affecting pathogenicity and transmissibility. Our goals are (1) to retrieve and analyze HA, NP and NA gene sequences of H5N1 Influenza A virus from diverse hosts, including humans, poultry and multiple mammalian species, to assess genetic diversity and evolutionary patterns and (2) to evaluate positive selection sites across the three major genes (HA, NP and NA) to determine adaptive mutations linked to host adaptation and viral survival. To achieve these goals, in this study, we considered (78 HA), (62 NP) and (61 NA) gene sequences from diverse hosts, including humans, poultry and multiple mammalian species, retrieved from the NCBI database. Phylogenetic analysis revealed distinct clade formations, indicating regional spread and cross-species transmission events, particularly from avian sources to mammals and humans. Selection pressure analysis identified positive selection across all three genes, suggesting adaptive mutations contributing to host adaptation and viral survival. Homology modeling and molecular dynamics simulations were performed to generate high-quality structural models of HA, NP and NA proteins, which were subsequently validated using multiple stereochemical parameters. Domain analysis confirmed conserved functional motifs, while protein–ligand docking demonstrated stable interactions at conserved binding sites, despite observed residue substitutions in recent isolates. Earlier research concentrated on HA alone; this study integrates HA, NP and NA genes for a broader understanding of viral evolution and adaptation. These findings highlight ongoing evolutionary changes in H5N1 genes that may enhance viral adaptability and pathogenicity, underscoring the need for continuous molecular surveillance and updated antiviral strategies. Full article

While omega-6 fatty acids play an important role in normal cell function, their excess in the diet is associated with an increased risk of developing diseases such as obesity, non-alcoholic fatty liver disease (NAFLD), inflammatory bowel disease (IBD) and Alzheimer’s disease. Furthermore, excessive intake has been shown to lead to chronic inflammation, which is related to increased production of reactive oxygen species (ROS). This conditioncan initiate lipid peroxidation in cell membranes, leading to the degradation of their fatty acids. One of the main products of omega-6 peroxidation is the α,β-unsaturated aldehyde, i.e., 4-hydroxynonenal (4-HNE), which is able to form four diastereoisomeric adducts with guanine. These 4-HNE adducts have been identified in the DNA of humans and rodents. Depending on their stereochemistry, they are able to influence double helix stability and cause DNA–DNA or DNA–Protein cross-links. Moreover, studies have shown that 4-HNE adducts formed in the human genome are considered mutation hotspots in hepatocellular carcinoma. Although the cell possesses defence mechanisms, without a well-balanced diet allowing correct cell function, they may not be sufficient to protect the genetic code. This review provides an overview of the molecular mechanisms underlying oxidative stress, lipid peroxidation, and the formation of DNA adducts. Particular emphasis is placed on the role of an omega-6-rich diet in inflammatory diseases, and on the formation of 4-HNE, which is a major product of lipid peroxidation, and its broader implications for genome stability, ageing, and disease progression. Full article

Advanced glycation end-products (AGEs) are formed by the non-enzymatic glycation of proteins, lipids, and nucleic acids due to the consumption of high-carbohydrate diets; their production is also promoted by a sedentary lifestyle as well as cigarette smoking. Elevated levels of AGEs in the circulatory system and internal organs of the body are commonly observed in a number of cardiovascular diseases such as hypertension, diabetes, atherosclerosis, coronary artery disease, aortic aneurysm, atrial fibrillation, myocardial infarction, and heart failure, which are associated with the development of oxidative stress and myocardial inflammation. The adverse effects of AGEs on the cardiovascular system are elicited by both non-receptor mechanisms involving the cross-linking of extracellular and intracellular proteins, and by receptor-mediated mechanisms involving the binding of AGEs with advanced glycation end-product receptors (RAGEs) on the cell membrane. AGE–RAGE interactions along with the cross-linking of proteins promote the generation of oxidative stress, the production of inflammation, the occurrence of intracellular Ca²⁺-overload, and alterations in the extracellular matrix leading to the development of cardiovascular dysfunction. AGEs also bind with two other protein receptors in the circulatory system: soluble RAGEs (sRAGEs) are released upon the proteolysis of RAGEs due to the activation of matrix metalloproteinase, and endogenous secretory RAGEs (esRAGEs) are secreted as a spliced variant of endogenous RAGEs. While the AGE–RAGE signal transduction axis serves as a pathogenic mechanism, both sRAGEs and esRAGEs serve as cytoprotective interventions. The serum levels of sRAGEs are decreased in ischemic heart disease, vascular disease, and heart failure, as well as in other cardiovascular diseases, but are increased in chronic diabetes and renal disease. Several interventions which can reduce the formation of AGEs, block the AGE–RAGE axis, or increase the levels of circulating sRAGEs have been shown to exert beneficial effects in diverse cardiovascular diseases. These observations support the view that the AGE–RAGE axis not only plays a critical role in pathogenesis, but is also an excellent target for the treatment of cardiovascular disease. Full article

This study investigated the effects of curdlan (CUR) with different helical conformations on the gelling behavior and mechanisms of heat-induced soy protein isolate (SPI) gels. The results demonstrated that CUR significantly improved the functional properties of SPI gels, including water-holding capacity (0.31–5.06% increase), gel strength (7.01–240.51% enhancement), textural properties, viscoelasticity, and thermal stability. The incorporation of CUR facilitated the unfolding and cross-linking of SPI molecules, leading to enhanced network formation. Notably, SPI composite gels containing CUR with an ordered triple-helix bundled structure exhibited superior gelling performance compared to other helical conformations, characterized by a more compact and uniform microstructure. This improvement was attributed to stronger hydrogen bonding interactions between the triple-helix CUR and SPI molecules. Furthermore, the entanglement of triple-helix CUR with SPI promoted the formation of a denser and more homogeneous interpenetrating polymer network. These findings indicate that triple-helix CUR is highly effective in optimizing the gelling characteristics of heat-induced SPI gels. This study provides new insights into the structure–function relationship of CUR in SPI-based gel systems, offering potential strategies for designing high-performance protein–polysaccharide composite gels. The findings establish a theoretical foundation for applications in the food industry. Full article