Search Results (645)

Haemonchus contortus is a blood-feeding gastrointestinal nematode that significantly impacts the health and productivity of small ruminants. The burden of parasitism and the escalating incidence of anthelmintic resistance necessitate alternative control methods. Here, we characterize the enzymatic activities of five mammalian cell-expressed recombinant H. contortus cysteine proteases (HcCPs), which include two cathepsin B-like proteins (HcCBP1 and HcCBP2) and three cysteine protease 1 proteins (HcCP1a, HcCP1b, and HcCP1c). We hypothesize that these enzymes degrade host blood proteins, thereby facilitating the parasite’s nutrient acquisition and survival. Using synthetic cathepsin (cat) substrates, we show that HcCBP2 was the only protein that exhibited high catB/L but low catB or catK activity, which was inhibited by the cysteine protease inhibitor E-64. All mHcCPs degraded fibrinogen (Fg), which led to delayed plasma clotting, reduced clot density, and lysed plasma clots. All HcCPs partially degraded hemoglobin (Hb), except for mHcCBP2, which degraded Hb and bovine serum albumin completely and bovine IgG partially in the presence of a reducing agent. In conclusion, by sustaining blood feeding and facilitating immune evasion and nutrient acquisition, the HcCPs may play an essential role in the parasite’s survival. Thus, vaccines or cysteine protease inhibitors targeting these parasitic enzymes may mitigate or prevent infections. Full article

Background/Objectives: Parkinson’s disease (PD) and Dementia with Lewy Bodies (DLB) are neurodegenerative disorders characterized by the accumulation of misfolded alpha-synuclein protein in the brain. Mutations in the glucocerebrosidase 1 (GBA1) gene have been identified as a significant genetic risk factor for both PD and DLB. GBA1 encodes for the lysosomal enzyme glucocerebrosidase, which is responsible for the breakdown of glucosylceramide (GC). Deficiencies in glucocerebrosidase activity lead to the accumulation of glucosylceramide within lysosomes, contributing to lysosomal dysfunction and impaired protein degradation. The aim of this narrative review is to update the underlying mechanisms by which GBA1 mutations contribute to the pathogenesis of PD and DLB. Methods: A comprehensive literature search was conducted across four major electronic databases (PubMed, Web of Science (Core Collection), Scopus, and Embase) from inception to 8 November 2025. The initial search identified approximately 1650 articles in total, with the number of hits from each database being as follows: PubMed (~450), Web of Science (~380), Scopus (~520), and Embase (~300). Results: The mechanism by which mutations in the GBA1 gene contribute to PD involves both loss-of- function and gain-of-function pathways, which are not mutually exclusive. Typically, GBA1 mutations lead to a loss of function by reducing the activity of the GCase enzyme, impairing the autophagy- lysosomal pathway and leading to α-synuclein accumulation. However, some mutant forms (GBA1L444P) of the GCase enzyme can also acquire a toxic gain of function, contributing to α-synuclein aggregation through mechanisms like endoplasmic reticulum stress and misfolding. While Venglustat effectively reduced GC levels, a key marker associated with GBA1-PD, the lack of clinical improvement led to the discontinuation of its development for this indication. Conclusions: GBA1-mediated lysosomal and lipid dysregulation represents a key pathogenic axis in PD and DLB. Understanding these mechanisms provides crucial insight into disease progression and highlights emerging therapeutic strategies—such as pharmacological chaperones, substrate reduction therapies, and gene-targeted approaches—aimed at restoring GCase function and lysosomal homeostasis to slow or prevent neurodegeneration. Full article

Anaerobic fungi (phylum Neocallimastigomycota) play a crucial role in degrading forages and fibrous foods in the gastrointestinal tract of mammalian herbivores, particularly ruminants. Currently, they are classified into twenty-two genera; however, recent research suggests the occurrence of several novel taxa that require further characterization. Anaerobic rumen fungi play a pivotal role in lignocellulose degradation due to their unique enzymatic capabilities. This review explores the enzymatic systems of rumen anaerobic fungi, highlighting their ability to produce a diverse array of carbohydrate-active enzymes (CAZymes), such as cellulases, hemicellulases, and pectinases. These enzymes facilitate the breakdown of complex plant polymers, making anaerobic fungi essential contributors to fiber degradation in the rumen ecosystem and valuable resources for biotechnological applications. This review summarizes the structural and functional diversity of fungal CAZymes, and the mechanical disruption of plant cell walls by fungal rhizoidal networks is discussed, showcasing the ability of fungi to enhance substrate accessibility and facilitate microbial colonization. Recent studies using genomic, transcriptomic, and biochemical approaches have uncovered several novel CAZymes in anaerobic fungi, including multifunctional xylanases, β-glucosidases, and esterases. These findings highlight the continued expansion of fungal enzyme repertoires and their potential for biotechnology and feed applications. Continued research in this field will enhance our understanding of microbial ecology and enzyme function, paving the way for applications that address global challenges in energy, food security, and environmental sustainability. Full article

Impaired intestinal proteolytic activity can lead to increased intestinal permeability. Differences in dietary protein intake may influence proteolytic activity in the digestive system. This study investigated whether intestinal proteolytic activity can be influenced by diet. Fecal samples from representative species of each different dietary group—carnivore, herbivore, and omnivore—were analyzed using fluorescence resonance energy transfer (FRET) peptide substrates to measure enzyme activity. Specific protease inhibitors were applied to identify the enzyme classes responsible for substrate degradation. Results showed that total proteolytic activity was significantly higher in feces from carnivores and omnivores than in those of herbivores. The addition of a serine protease inhibitor substantially reduced substrate degradation, indicating that serine proteases accounted for most of the observed activity. These findings demonstrate that proteolytic activity in feces is closely related to dietary protein intake and suggest that the regulation of proteases in the digestive tract may be influenced by feeding behavior and nutritional requirements. Full article

Dalbergia odorifera, a cornerstone tree species for ecological restoration in karst regions, exhibits remarkable adaptability to karst rocky desertification (KRD) environments characterized by high heterogeneity and nutrient poverty. Yet, the mechanisms underlying its root system’s response to spatially variable KRD stress remain poorly elucidated. In this study, a split-root system was employed to simulate heterogeneous substrate conditions, including loam, uniform gravel (global stress), and partitioned loam/gravel (partial stress). We found that under partial stress, the root system underwent functional specialization, and roots in loam enhanced resource acquisition, whereas roots in gravel significantly elevated stress tolerance. This was supported by increased root:shoot ratio, improved nutrient conservation, and localized upregulation of key enzymes and metabolites. Multi-omics profiling further uncovered profound reprogramming of critical pathways such as phenylpropanoid biosynthesis, fatty acid metabolism, and glutathione metabolism, highlighting robust antioxidant defense and membrane stabilization mechanisms. Our findings demonstrate that D. odorifera optimizes resource use in heterogeneous karst habitats through spatial division of labor at the root system level, orchestrated by integrated morphological, physiological, and molecular adaptations. This study provides a novel perspective on plant adaptation to environmental heterogeneity and offers practical insights for cultivating stress-resilient trees and restoring degraded karst ecosystems. Full article

The M16 protease family comprises metalloendopeptidases, characterized by a unique molecular architecture. The active enzyme molecule is composed of two halves, which together form a structure resembling a clam shell. Although the active site residues are typically located in only one half, both parts are essential for proper enzyme function. The M16 family includes many proteins that are crucial for the physiology of the organism and, therefore, are the subject of intensive research. The flagship examples are insulin-degrading enzyme (IDE), mitochondrial processing peptidases (MPPs), and mitochondrial and chloroplast presequence peptidases (PrePs). The substrates of these enzymes include many biologically important peptides, such as insulin and amyloid β. Therefore, M16 peptidases are considered attractive therapeutic targets, and understanding their structure and mechanism of action is essential for the development of specific and selective modulatory compounds. Full article

Glutathione reductase (GR) is essential for maintaining cellular redox homeostasis by sustaining reduced glutathione (GSH) levels. In Hypsizygus marmoreus, GR silencing led to impaired mycelial growth, elevated reactive oxygen species (ROS) accumulation, and disrupted antioxidant enzyme activity, ultimately hindering fruiting body development. Mitochondrial size was markedly reduced in GR-silenced strains, indicating compromised cellular metabolism. Supplementation with the reducing agent vitamin C (Vc) partially restored redox balance and enzyme activity in a developmental stage–dependent manner, alleviating the defects caused by GR suppression. Moreover, GR was found to influence lignocellulose-degrading enzyme activity, further linking redox regulation to substrate utilization. Overall, these findings demonstrate that GR plays a central role in coordinating redox balance, energy metabolism, and enzyme function in H. marmoreus, providing new insights for enhancing industrial mushroom production through antioxidant regulation. Full article

The degradation of sandy land in Inner Mongolia presents a substantial threat to regional ecological security and the sustainable development of agriculture and animal husbandry. Planting alfalfa serves as a crucial recovery strategy; however, the inadequate capacity to retain water and nutrients impedes this process. The current reliance on a singular microbial remediation method has demonstrated limited effectiveness in addressing the challenges posed by sandy soil. While traditional sand-fixing agents can improve soil nutrients, they lack biological activity. Furthermore, the synergistic mechanisms between these approaches and their ecological impacts within a single season remain poorly understood. This study involved a pot experiment utilizing wind-sand soil as the substrate to evaluate the soil physicochemical properties, enzyme activities, and microbial community structure associated with the stress resistance of alfalfa. The results indicated that the medium concentration of sand-fixing agent (1:75) exhibited optimal water retention performance, thereby creating a conducive growth microenvironment for Trichoderma longibrachiatum and mitigating fluctuations in surface temperature and humidity. The combined treatment significantly improved the alpha diversity of soil microorganisms, thereby improving the stability and stress resistance of the system. Through the synergistic approach of “sand fixation and water retention–nutrient activation–improved stress resistance”, the microenvironment of sandy land was effectively improved, promoting alfalfa growth. This method offers “environmentally friendly and synergistic” technical support for the efficient cultivation and ecological restoration of alfalfa in sandy regions, while also contributing to the high-quality development of grassland animal husbandry. Full article

Background: Although antivenom is the standard treatment for snakebite envenoming, its efficacy may be impacted by geographic variation in venom composition, emphasizing the need for region-specific antivenom development. Methods: We report a case of snakebite envenoming, in which the patient was bitten on the hand by a captive Malayan pit viper (Calloselasma rhodostoma) with typical clinical manifestations following. Antivenom (produced in Thailand) was administered at 33 and 39 h post-bite. Venom from the causative individual snake was collected for compositional analysis via SDS-PAGE. Enzymatic activity of the venom was evaluated through the degradation of casein and phospholipid substrates, along with the assessment of enzymatic inhibition by two regionally specific antivenoms produced in Vietnam (AV. Cr. VN.) and Thailand (AV. Cr. TL.). Results: The patient showed good recovery, with complete normalization by day 7. SDS-PAGE profiling of the venom revealed five major enzymes, with SVSP, SVMP and PLA₂ being the most abundant (16.7%, 40.11% and 26.11%, respectively). Antivenom inhibition tests revealed remaining casein percentages of 67.43% (AV. Cr. VN) and 59.35% (AV. Cr. TL). Blood agar assays indicated that phospholipase activity was reduced to 21.01% by AV. Cr. VN. and 23.30% by AV. Cr. TL. Conclusions: Our results show that the Vietnamese antivenom generated greater inhibitory activity against proteinases compared to the Thai product, underscoring the importance of using regionally specific antivenoms that are more effective against the venom profiles of locality-matched snake populations. Full article

This study explores the potential of two marine-derived bacteria, Cytobacillus kochii and Marinobacter, through in silico analysis of their catechol 2,3-dioxygenase (C23O) enzymes. Molecular docking simulations were conducted using AutoDock Vina to assess the binding interactions between C23O enzymes and ten hydrocarbon pollutants, including monocyclic and polycyclic aromatic hydrocarbons (PAHs). Binding affinities ranged from −4 to −8.7 kcal/mol for Cytobacillus kochii, with the highest affinity observed for fluoranthene (−8.7 kcal/mol), followed by pyrene (−8.5 kcal/mol) and phenanthrene (−8.2 kcal/mol). In comparison, Marinobacter’s C23O showed binding affinities between −4.1 and −8 kcal/mol, with fluoranthene (−8 kcal/mol) and phenanthrene (−7.9 kcal/mol) being top performers. Despite slightly lower affinity, Marinobacter exhibits superior environmental resilience under high salinity and temperature, making it valuable for application in fluctuating marine conditions. Structural interaction analysis revealed consistent pi-pi stacking and hydrogen bonding within the active sites, further supporting enzyme–substrate compatibility. These computational findings underscore Cytobacillus kochii ’s superior catalytic potential and Marinobacter’s ecological robustness. The integration of both strains into a microbial consortium offers a promising synergistic approach, combining enzymatic efficiency and environmental adaptability for effective hydrocarbon degradation. While these computational assessments offer valuable predictive insights, further validation through in vitro and in vivo experiments would be beneficial to determine the actual hydrocarbon degradation efficiencies. Full article

Dark fermentation of food waste for biohydrogen production can simultaneously achieve waste resource utilization and clean energy production. However, the widespread application of this technology remains constrained by challenges such as low substrate hydrolysis efficiency and suboptimal metabolic performance of functional microorganisms. This study evaluated the synergistic enhancement of biohydrogen production from food waste through dark fermentation by integrating thermal–alkaline (TA) pretreatment with varying concentrations (50, 100, 150, and 200 mg/L) of nickel–cobalt oxide nanoparticles (NiCo₂O₄ NPs), and the underlying mechanisms involved were systematically elucidated. The results demonstrated that individual TA pretreatment (pH 11, 70 °C, 1 h) and TA coupled with NiCo₂O₄ NPs (100 mg/L) significantly (p < 0.01) enhanced the cumulative biohydrogen yields of the food waste dark fermentation by 20.89% and 35.76%, respectively. Mechanism research revealed that TA pretreatment effectively facilitated the dissolution and hydrolysis of macro-molecular organics such as polysaccharides and proteins, thereby enhancing the bio-accessibility of fermentation substrates. The introduction of NiCo₂O₄ NPs further intensified the microbial biohydrogen-producing metabolism by augmenting enzymatic activity and enriching functional bacteria. NiCo₂O₄ NPs significantly (p < 0.001) enhanced the overall activity of hydrogenase by 95.10% compared to the control group (CG) by providing the cofactor of hydrogenase and accelerating electron transfer. Additionally, this synergistic strategy significantly (p < 0.01) increased the activities of hydrolases (e.g., protease and α-glucosidase), as well as key enzymes in acetate-type and butyrate-type fermentation pathways (e.g., acetate kinase and butyrate kinase), and enriched the biohydrogen-producing microbial community centered on Clostridium_sensu_stricto_1. This study systematically elucidated the synergistic strategy of TA pretreatment and NiCo₂O₄ NPs, which achieved dual-pathway reinforcement from substrate degradability to microbial metabolic activity. The findings are expected to provide theoretical support for developing efficient biohydrogen production technology from perishable organic solid waste. Full article

This study utilized rapeseed straw as the raw material and employed a completely randomized design with four treatments: a distilled water control (CK), individual supplementation of Lactiplantibacillus plantarum (1.0 × 10⁶ CFU/g fresh weight) (Lp), individual supplementation of xylanase (50,000 U/g fresh weight) (XY), and a combined bacterium–enzyme treatment (XYLp). Each treatment was replicated five times, vacuum-sealed, and fermented at 25 °C for 60 days to systematically evaluate the effects of different treatments on the fermentation quality, nutritional composition, and microbial community structure of rapeseed straw silage. The results demonstrated that, compared with the CK group, all additive treatments significantly decreased pH and increased lactic acid (LA) content (p < 0.05). Among them, the Lp group exhibited the lowest pH value (4.27), which was significantly lower than all other treatments except XYLp (p < 0.05). Both the Lp and XYLp groups showed significantly higher LA content than the other groups (p < 0.05). Crude protein (CP) content was significantly higher in all additive treatments than in the CK group (p < 0.05). The XYLp group exhibited the most substantial fiber degradation, with acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents being significantly lower than CK and reaching the lowest values among all treatments (p < 0.05). Both the XY and XYLp groups showed significantly lower hemicellulose and holocellulose contents compared to the CK and Lp groups (p < 0.05). Microbial community analysis revealed that the synergistic bacterium–enzyme treatment significantly enriched fibrolytic genera, including Kosakonia and Pediococcus, and upregulated the expression of key fibrolytic enzymes such as cellulase (EC: 3.2.1.4), β-glucosidase (EC: 3.2.1.21), and endo-1,4-β-xylanase (EC: 3.2.1.8). Functional prediction further indicated that the bacterial–enzyme synergy enhanced fibrous structure degradation and fermentable substrate release by activating carbohydrate metabolism pathways and bacterial secretion systems. These findings suggest that the combined application of Lactiplantibacillus plantarum and xylanase has the potential to be a promising strategy for enhancing fiber degradation and overall fermentation quality in rapeseed straw silage. Full article

Straw returning is a critical practice with profound strategic importance for sustainable agricultural development. However, within a comprehensive soil health evaluation framework, research analyzing the impact of tobacco straw returning on soil ecosystem health from the perspectives of microbial taxa and functional genes remains insufficient. To investigate the effects of tobacco straw returning on virulence factor genes (VFGs), methane-cycling genes (MCGs), nitrogen-cycling genes (NCGs), carbohydrate-active enzyme genes (CAZyGs), antibiotic resistance genes (ARGs), and their host microorganisms in soil, this study collected soil samples from a long-term tobacco-rice rotation field with continuous tobacco straw incorporation in Shaowu City, Fujian Province. Metagenomic high-throughput sequencing was performed on the samples. The results demonstrated that long-term tobacco straw returning influenced the diversity of soil VFGs, MCGs, NCGs, CAZyGs, ARGs, and their host microorganisms, with richness significantly increasing compared to the CK treatment (p < 0.05). In the microbially mediated methane cycle, long-term tobacco straw returning resulted in a significant decrease in the abundance of the key methanogenesis gene mttB and the methanogenic archaeon Methanosarcina, along with a reduced mtaB/pmoA functional gene abundance ratio compared to CK. This suggests enhanced CH₄ oxidation in the tobacco-rice rotation field under straw returning. Notably, the abundance of plant pathogens increased significantly under tobacco straw returning. Furthermore, a significantly higher norB/nosZ functional gene abundance ratio was observed, indicating a reduced capacity of soil microorganisms to convert N₂O in the tobacco-rice rotation field under straw amendment. Based on the observation that the full-rate tobacco straw returning treatment (JT2) resulted in the lowest abundances of functional genes prkC, stkP, mttB, and the highest abundances of nirK, norB, malZ, and bglX, it can be concluded that shifts in soil physicochemical properties and energy substrates drove a transition in microbial metabolic strategies. This transition is characterized by a decreased pathogenic potential of soil bacteria, alongside an enhanced potential for microbial denitrification and cellulose degradation. Non-parametric analysis of matrix correlations revealed that soil organic carbon, dissolved organic carbon, alkaline-hydrolyzable nitrogen, available phosphorus, and available potassium were significantly correlated with the composition of soil functional groups (p < 0.05). In conclusion, long-term tobacco straw returning may increase the risk of soil-borne diseases in tobacco-rice rotation systems while potentially elevating N₂O and reducing CH₄ greenhouse gas emission rates. Analysis of functional gene abundance changes identified the full-rate tobacco straw returning treatment as the most effective among all treatments. Full article

R-loops are three-stranded nucleic acid structures implicated in genome regulation and stability. In Arabidopsis thaliana, the chloroplast-localized RNase H1 enzyme (AtRNH1C) is important for chloroplast development and genome integrity; however, its molecular activity has not been experimentally verified. In the present study, we characterized the enzymatic activity of recombinant AtRNH1C toward model R-loops of various structures. Using a set of synthetic R-loop substrates, we demonstrate that AtRNH1C cleaves the RNA within DNA/RNA hybrids with a strong preference for purine-rich sequences, most notably at G↓X dinucleotides. Kinetic assays showed that the enzyme’s efficiency is highly dependent on the length of the hybrid duplex but is not affected by a G-quadruplex structure in the single-stranded DNA flap of the R-loop. The most rapid degradation was observed for an R-loop with an 11 nt DNA/RNA hybrid region. This study provides a comparative analysis of chloroplast-localized RNase H1 activity and elucidates its substrate preferences, suggesting that an R-loop with a heteroduplex length closest to the native size found in transcription elongation complexes is the most efficient substrate. These findings suggest that the enzymatic activity of AtRNH1C is sufficient to perform its function in maintaining chloroplast genome stability by the degradation of R-loops in DNA. Full article

The accumulation of polyethylene terephthalate (PET) in the environment demands efficient microbial strategies for its degradation. This study evaluates the biodegradation potential of Schizophyllum commune BNT39 toward bis(2-hydroxyethyl) terephthalate (BHET), a major PET intermediate, and PET itself. Clear halos on BHET-agar plates indicated extracellular hydrolytic activity. In liquid culture, thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses revealed a three-phase degradation profile characterized by rapid BHET hydrolysis, transient dimer accumulation, and subsequent conversion to terephthalic acid (TPA). BHET was reduced by approximately 96% within seven days, while TPA accumulation reached 0.8 mg/mL after 30 days of incubation. Although PET degradation was limited, TPA was consistently detected as the principal product, with no BHET or MHET intermediates. To explore strategies for enhancing enzymatic activity, apple-derived cutin, PET, BHET, and polycaprolactone (PCL) were tested as inducers. Cutin markedly stimulated extracellular enzyme production, suggesting activation of cutinase-like enzymes. Overall, S. commune BNT39 demonstrates the ability to transform PET-related substrates, with cutin emerging as a promising natural stimulant to enhance enzymatic depolymerization. Future studies should focus on enzyme purification, activity profiling, and reaction optimization near PET’s glass transition temperature, where the polymer becomes more accessible for enzymatic attack. Full article