Search Results (583)

L-asparaginase (L-ASNase) is a vital enzymatic drug widely used for treating acute lymphoblastic leukemia (ALL) and certain lymphomas. However, its clinical application is often limited by a short plasma half-life, pronounced immunogenicity, and systemic toxicities. To address these challenges, we recently developed conjugates of L-ASNase with cationic polymers, enhancing its cytostatic activity by increasing enzyme binding with cancer cells. The present study focuses on the development of liposomal formulations of E. coli L-asparaginase (EcA) and its conjugates with cationic polymers: the natural oligoamine spermine (spm) and a synthetic polyethylenimine–polyethyleneglycol (PEI-PEG) copolymer. This approach aims to improve enzyme encapsulation efficiency and stability within liposomes. Various formulations—including EcA conjugates with polycations incorporated into 100 nm and 400 nm phosphatidylcholine/cardiolipin (PC/CL, 80/20) anionic liposomes—were synthesized as a delivery system of high enzyme load. Fourier Transform Infrared (FTIR) spectroscopy confirmed successful enzyme association with liposomal carriers by identifying characteristic changes in the vibrational bands corresponding to both protein and lipid components. In vitro release studies demonstrated that encapsulating EcA formulations in liposomes more than doubled their half-release time (T_1/2), depending on the formulation. Cytotoxicity assays against Raji lymphoma cells revealed that liposomal formulations, particularly 100 nm EcA-spm liposomes, exhibited markedly superior anti-proliferative activity, reducing cell viability to 4.5%, compared to 35% for free EcA. Confocal Laser Scanning Microscopy (CLSM) provided clear visual and quantitative evidence that enhanced cellular internalization of the enzyme correlates directly with its cytostatic efficacy. Notably, formulations showing higher intracellular uptake produced greater cytotoxic effects, emphasizing that hydrolysis of asparagine inside cancer cells, rather than extracellularly, is critical for therapeutic success. Among all tested formulations, the EcA-spermine liposomal conjugate demonstrated the highest fluorescence intensity within cells providing enhanced cytotoxicity. These results strongly indicate that encapsulating cationically modified L-ASNase in liposomes is a highly promising strategy to improve targeted cellular delivery and prolonged enzymatic activity. This strategy holds significant potential for developing more effective and safer antileukemic therapies. Full article

Soil salinization threatens global food security, necessitating the development of saline–alkaline-tolerant crops. This study investigated the molecular mechanisms of alkali stress tolerance in maize. Screening 369 inbred lines identified two alkali-resistant and two alkali-sensitive varieties. Systematic analysis revealed that resistant varieties rapidly lowered rhizosphere pH and maintained root architecture, whereas sensitive varieties suffered reduced lateral roots and severe biomass loss. Metabolomic profiling showed that all varieties secreted malonic acid via the pyrimidine pathway to modulate rhizosphere pH, with resistant varieties exhibiting stronger accumulation. Transcriptome and RT-qPCR analysis identified two key genes: Zm00001eb396990 (asparagine synthetase), upregulated in resistant varieties and linked to organic acid synthesis, and Zm00001eb370000 (cytokinin dehydrogenase), downregulated in resistant varieties, potentially aiding root maintenance. Multi-omics correlation confirmed the association between Zm00001eb396990 expression and malonic acid content. This study demonstrates that maize roots can alleviate alkali stress through the secretion of malonic acid and the regulation of related genes, providing potential genetic targets and a theoretical basis for cultivating alkali-tolerant maize. Full article

In recent years, amyloid proteins that perform vital functions in the brain have been characterized. The question of why some amyloids are neurotoxic while others are harmless remains open. Here, we provide a brief overview of pathological and functional brain amyloids and present a comparative analysis of their amino acid sequences based on the percentage of hydrophobic and charged residues, as well as their enrichment in glutamine, asparagine, serine, and glycine. We demonstrate that pathological and functional brain amyloid proteins, along with their amyloidogenic fragments, do not differ in amino acid composition, contrary to previous assumptions. The ability of an amyloid to cause toxicity can instead be explained by the concept of “available targets”. Evidence from studies of pathological amyloids demonstrate that their toxicity is determined not only by a loss of function but also by aberrant interactions with specific targets, such as PrP^C or mitochondrial membranes. Binding to these targets triggers pathological cascades that ultimately lead to cell death. In contrast, such targets are inaccessible to functional amyloids, either because of localized translation and protein sequestration within specialized cellular structures, or because their interactions with physiological partners prevent binding to dangerous targets. Full article

Background/Objectives: Endometriosis (EM) is a chronic gynecological condition associated with infertility, oxidative stress, and altered metabolic regulation. Follicular fluid (FF) reflects the microenvironment of the developing oocyte, and changes in its amino acid composition may affect reproductive outcomes. This study aimed to characterize alterations in the amino acid composition of the FF in EM and to identify potential reproductive outcomes. Methods: Targeted metabolomic analysis of 20 amino acids was performed on FF samples from 56 women undergoing in vitro fertilization (17 with endometriosis, 39 controls). Amino acid concentrations were quantified and compared between groups, adjusting for age and body mass index. Pathway, biomarker, and multivariate analyses were conducted to explore metabolic alterations and potential diagnostic markers. Results: Asparagine, histidine, and glycine concentrations were significantly higher in the EM group after adjustment for age and BMI. Pathway analysis indicated perturbations in glycine/serine metabolism, glutathione metabolism, and porphyrin metabolism, consistent with oxidative stress and mitochondrial dysfunction. Multivariate modeling demonstrated partial separation between groups, while biomarker analysis identified asparagine (AUC = 0.76), along with glycine and histidine, as potential discriminators. Additional enrichment of bile acid and methylation-related pathways suggested broader systemic metabolic changes in EM. Conclusions: EM is associated with distinct amino acid alterations in the FF, particularly elevated asparagine, histidine, and glycine, reflecting oxidative and mitochondrial imbalance in the follicular environment. These metabolites emerged as candidate biomarkers requiring validation for EM-related oocyte quality changes and may help individualize in vitro fertilization approaches. Full article

Background/Objectives: Vitamin C plays a vital role in human health, functioning as a powerful antioxidant and enzymatic cofactor. Although vitamin C bioavailability from food versus supplements has been debated, few studies have examined how intake form affects absorption and physiological markers. Methods: This randomized, controlled, crossover trial aimed to compare the bioavailability of vitamin C consumed as a supplement, through raw fruits and vegetables, or through fruit and vegetable juice. Twelve healthy adults underwent three 1-day crossover trials, each separated by a 2-week washout. Participants consumed 101.7 mg of vitamin C via powder, raw fruits and vegetables (186.8 g), or juice (200 mL). Plasma and urinary vitamin C concentrations, urinary metabolites (¹H NMR), and antioxidant activity (ORAC and TRAP) were assessed over 24 h. Results: All interventions elevated plasma vitamin C levels, with juice yielding the highest AUC (25.3 ± 3.2 mg/dL·h). Urinary vitamin C increased in all groups. Metabolomics revealed increased urinary excretion of mannitol, glycine, taurine, dimethylglycine (DMG), and asparagine, and decreased choline and dimethylamine (DMA). Notably, urinary mannitol increased only in the morning. Choline significantly decreased after powder intake (p = 0.001), with similar trends observed in the other groups. DMG and glycine increased following raw and juiced vegetable intake. Antioxidant activity showed transient ORAC elevation post-powder but no sustained improvements. Conclusions: Vitamin C is bioavailable from all intake forms, with juice providing the most efficient absorption. Urinary metabolite changes suggest microbiota-related modulation, while antioxidant activity improvements were limited. Full article

Despite the availability of effective vaccines, yellow fever outbreaks persist, highlighting the need for antiviral drugs. Background/Objectives: This study investigated Hippeastrum puniceum (Amaryllidaceae) as a potential source of antiviral compounds against wild-type yellow fever virus (wt-YFV). Methods/Results: The crude bulb extract of H. puniceum exhibited 58% protection against wt-YFV. Bioassay-guided fractionation of the extract by UHPLC-HRMS led to the annotation of six alkaloids (bulbisine, cathinone, trigonelline, tetrahydroharman-3-carboxylic acid, and 2,7-dimethoxyhomolycorine or 3-O-acetylnarcissidine) in active fractions, along with the amino acids arginine, asparagine, tryptophan, and glutamic acid. In silico ADMET analyses predicted favorable pharmacokinetic and toxicological profiles, supporting their potential as drug candidates. Six of the annotated compounds were evaluated in vitro for cytotoxicity and antiviral activity against wt-YFV. However, none showed significant antiviral activity when tested individually, suggesting that the observed antiviral effect may result from synergistic interactions between two or more compounds within active fractions. Conclusions: Our results underscore the importance of further investigations in vitro, particularly assays exploring the synergy among the annotated compounds against YFV. The integration of bioassay-guided fractionation of active plant extracts with computational analyses emerges as a promising strategy for the discovery of natural products with therapeutic potential against yellow fever, a reemerging disease. Full article

Bioactive glycopeptides, commonly present in natural foods, exhibit notable immunomodulatory and neuroprotective effects. However, naturally occurring low-molecular-weight glycopeptides have rarely been reported, and their structural and functional properties remain insufficiently explored. In this study, a low-molecular-weight glycopeptide complex (GLP-P) was isolated from kefir. The structure of GLP-P was characterized via molecular weight (Mw) determination, monosaccharide and amino acid composition analysis, Fourier transform infrared spectroscopy, methylation analysis, and nuclear magnetic resonance spectroscopy. GLP-P had a molecular weight of 1192 Da and mainly consisted of four monosaccharides (glucose 64.7%, galactose 34.4%, and others 2.0%) and eight amino acids (asparagine 30.89 ± 0.01 μg/mg, threonine 8.71 ± 0.04 μg/mg, serine 9.5 ±0.08 μg/mg and others.). The primary chain structure of GLP-P contained β-D-Galp-(1→4)-β-D-Glcp-(1→4)-α/β-D-Glcp linkages, including both α- and β-D-Glcp isomers. Notably, the HMBC spectrum of GLP-P exhibits putative O-glycosylation characteristics. Functionally, GLP-P significantly reduced IL-6 and TNF-α expression while enhancing IL-10 in LPS-stimulated RAW264.7 macrophages. These effects were associated with inhibition of the TLR4/NF-κB pathway. These findings suggest that low-molecular-weight GLP-P has shown potential efficacy in the treatment of inflammation in vitro. These results provide a theoretical basis for kefir glycopeptide development of functional foods and as an adjuvant therapeutic agent for inflammation-related disorders in the future. Full article

This study examined how different water restriction levels (T100%, T85%, T75%, and T55%) influence the nutritional and bioactive compounds of Bahar and Dadaş cress (Lepidium sativum L.) cultivars. The highest levels of phenolic compounds found in Dadaş and Bahar cress were quercetin (8.33 ± 0.23–9.32 ± 0.25 µg/L), ferulic acid (8.08 ± 0.18–8.42 ± 0.19 µg/L), catechin (6.83 ± 0.28 µg/L), and caftaric acid (5.40 ± 0.45 µg/L). Mild and moderate drought treatments (85% and 75% humidity) caused notable increases in phenolic compounds. The highest antioxidant enzyme levels were observed as GST, 6GPD, and G6PD in Bahar and Dadaş cress, with enzyme levels rising under drought conditions. Notably, the mild drought treatment roughly doubled peonidin-3-glucoside acetyl levels in the cress cultivars. Sugar contents of Dadaş and Bahar cress cultivars also rose significantly with drought treatment. Riboflavin, the most abundant vitamin in cress cultivars, increased to 40.96 ± 1.24 mg/kg in Dadaş and 30.79 ± 1.60 mg/kg in Bahar cress under drought stress. Amino acids showed the highest increases under severe drought, with asparagine rising by roughly 2.76-fold and leucine increasing by 2.67-fold in Bahar cress. These findings suggest that controlled water restriction can enhance the nutritional and bioactive properties of cress, potentially leading to more nutrient-rich products for the food industry and human health. Full article

The antigenic relationship between Eurasian avian-like H1N1 swine influenza viruses (EA H1N1) and human pandemic 2009 H1N1 viruses (2009/H1N1) remains a critical question for influenza surveillance and vaccine efficacy. This study systematically investigated the antigenic differences between strains A/swine/Tianjin/312/2016 (TJ312, EA H1N1) and A/Guangdong-Maonan/SWL1536/2019 (GD1536, 2009/H1N1). Cross-hemagglutination inhibition (HI) assays revealed a significant antigenic disparity, with a 16-fold reduction in heterologous versus homologous HI titers. Comparative sequence analysis identified 22 amino acid differences across the five major antigenic sites (Sa, Sb, Ca1, Ca2, and Cb) of the HA1 subunit. Using reverse genetics, a panel of mutant viruses was generated. This study revealed that a single histidine (H)-to-asparagine (N) substitution at residue 128 (H3 numbering) in the Sa antigenic site acts as a primary determinant of antigenic variation, sufficient to cause a four-fold change in HI titers and a measurable drift in antigenic distance. Structural modeling via AlphaFold3 and PyMOL software suggests that the H128N mutation may alter the local conformation of the antigenic site. It is plausible that H at position 128 could exert electrostatic repulsion with adjacent amino acids, whereas N might facilitate hydrogen bond formation with neighboring residues. These interactions would potentially lead to structural changes in the antigenic site. Our findings confirm that residue 128 is a critical molecular marker for the antigenic differentiation of EA H1N1 and 2009/H1N1 viruses. The study underscores the necessity of monitoring specific HA mutations that could reduce cross-reactivity and provides valuable insights for refining vaccine strain selection and pandemic preparedness strategies. Full article

Background: Colorectal cancer (CRC) is significantly associated with multiple metabolic diseases, with plasma metabolites potentially mediating this relationship. This large-scale metabolomics study aims to (1) quantify the genetic correlations and causal effects between 10 metabolic disease-related phenotypes and CRC risk; (2) identify the plasma metabolites mediating these effects; and (3) explore downstream regulatory genes and druggable targets. Methods: Using linkage disequilibrium score regression and two-sample Mendelian randomization, we assessed the causal relationships between each metabolic trait and CRC. A total of 1091 plasma metabolites and 309 metabolite ratios were identified and analyzed for mediating effects by a two-step MR approach. Colocalization analyses evaluated shared genetic loci. The findings were validated in the UK Biobank for metabolite-trait associations. The expression of candidate genes was explored using data from TCGA, GTEx, and GEO. A FADS1-centered protein–protein interaction (PPI) network was constructed via STRING. Results: BMI, waist circumference, basal metabolic rate, insulin resistance and metabolic syndrome exhibited both genetic correlation and causal effects on CRC. Five plasma metabolites—mannonate, the glucose/mannose ratio, plasma free asparagine, 1-linolenoyl-2-linolenoyl-GPC (18:2/18:3), and the mannose/trans-4-hydroxyproline ratio—were identified as shared central mediators. A colocalization analysis showed rs174546 linked CRC and 1-linolenoyl-2-linoleoyl-GPC. Validation in the UK Biobank confirmed the associations between phosphatidylcholine (the lipid class of this metabolite), adiposity measures, and CRC risk. An integrative analysis of TCGA, GTEx, and GEO revealed consistent upregulation of FADS1/2/3 and FEN1 in CRC, with high FADS1 expression predicting a poorer prognosis and showing the distinct cell-type expression in adipose and colon tissue. The PPI network mapping uncovered nine FADS1 interacting proteins targeted by supplements such as α-linolenic acid and eicosapentaenoic acid. Conclusions: This study systematically reveals, for the first time, the shared intermediary plasma metabolites and their regulatory genes in the causal pathway from metabolic diseases to CRC. These findings provide candidate targets for subsequent functional validation and biomarker development. Full article

A novel species of the genus Methylocystis is proposed based on polyphasic evidence from strain SC2^T, isolated from the heavily polluted Saale River near Wichmar, Germany. Digital DNA–DNA hybridization and phylogenomic analyses demonstrate that strain SC2^T represents a distinct species within the genus, clearly separated from its closest relatives, namely Methylocystis suflitae NLS-7^T, Methylocystis rosea SV97^T, Methylocystis silviterrae FS^T, and Methylocystis hirsuta CSC1^T. As is typical of the family Methylocystaceae, cells possess intracytoplasmic membranes arranged parallel to the cytoplasmic membrane, and the dominant fatty acids are C18:1ω8c and C18:1ω7c. The strain grows aerobically on methane as the primary carbon and energy source and expresses both low- and high-affinity particulate methane monooxygenase (pMMO), but lacks the soluble form. The species epithet reflects the strain’s ability to utilize hydrogen as an alternative energy source. A further feature is its use of asparagine as an osmoprotectant, enhancing salt tolerance. Genomic analysis reveals complete pathways for nitrogen fixation, denitrification, and hydrogen oxidation. These genetic and physiological characteristics support the designation of a novel species, for which the name Methylocystis hydrogenophila sp. nov. is proposed. The type strain is SC2^T (=DSM 114506 = NCIMB 15437). Full article

White tea quality is primarily determined by its chemical composition, which varies significantly among cultivars. This study aimed to elucidate the chemical basis underlying quality differentiation in Baimudan white tea produced from three major Fujian tea cultivars: “Zhenghe Dabaicha” (ZHDB), “Fuan Dabaicha” (FADB), and “Fuding Dahaocha” (FDDH). Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), liquid chromatography–mass spectrometry (LC-MS), and quantitative descriptive analysis (QDA) were employed to characterize volatile compounds, amino acids, and saccharides. Odor Activity Values (OAVs) and Taste Activity Values (TAVs) were calculated to identify key contributors to sensory perception. Results showed that theanine, glutamic acid, asparagine, and serine were the primary contributors to umami taste, especially in ZHDB and FADB. Sweetness differences were largely due to sucrose, serine, and asparagine. OAV analysis further identified 22 critical aroma compounds: methyl salicylate, linalool, and β-ionone predominantly imparted floral notes, while β-ocimene, benzaldehyde, and geraniol enhanced sweet and fruity aromas. In contrast, (Z)-3-hexenol, (Z)-3-hexenal, and (E)-2-hexenal contributed grassy and refreshing characteristics, together defining the unique aroma profiles of each cultivar. This study provides an integrated chemical and sensory framework for understanding white tea quality variation, offering a theoretical basis for targeted flavor modulation. Full article

This study explores the production of nutritious edible mushrooms from mixtures of agave bagasse, an abundant agroindustrial byproduct, through the biotechnological application of solid-state fermentation using the edible mushroom Pleurotus djamor. The ability of the fungus to biotransform different mixtures of agave bagasse and corn stover into secondary metabolites of nutraceutical interest, such as polyphenols, organic acids, and bioactive polysaccharides, was evaluated. Biological efficiency (BE), morphological change, texture, and antioxidant capacity were also assessed, correlating the results with the impact of substrates and fungal developmental stages. The color, size, and margin of P. djamor basidiomas were observed to vary among treatments; BE progressively decreased from T0 (106.5%) to T4 (33.16%). Treatments with higher amounts of agave bagasse (T4) generated firmer fungi, with a fracture toughness of 7.06 ± 3.06 newtons. During fungal development, phenols, flavonoids, and tannins fluctuated. Treatment T0 showed the highest concentration of phenols (5.41 ± 0.92 mg GAE g⁻¹). Treatment T4 stood out for its high antioxidant capacity (DPPH) (61.83 ± 12.16% inhibition). Finally, 17 non-phenolic secondary metabolites were found: L-valine, L-leucine, L-isoleucine, L, D-phenylalanine, L-proline, alanine, L-asparagine, serine, glutamic acid, linoleic acid, palmitic acid, butanoic acid, propanoic acid, pyrimidine, succinic acid, hexanedioic acid, and phosphoric acid. In conclusion, P. djamor can biotransform agroindustrial waste into edible fungi containing nutraceutical compounds. Full article

The depletion of high-grade copper ore reserves in Kazakhstan, coupled with the increasing proportion of refractory ores and the high costs of extraction and processing, necessitates the development of efficient and economically viable technological solutions. In this context, biogeotechnology has gained considerable attention. Recently, alternative approaches based on the use of natural organic compounds—so-called bioreagents—have been introduced into the field of bioleaching. The present study aimed to investigate the effect of amino acids, aliphatic alcohols, and alcohol-based industrial by-products, used as bioadditives, on the bioleaching of copper. The results demonstrated that the influence of amino acids on copper bioleaching decreased in the following order: glycine > leucine > cysteine > histidine > asparagine. Furthermore, the addition of fusel oils, a mixture of aliphatic alcohols, to the bioleaching pulp enhanced copper recovery, achieving extraction efficiencies exceeding 90%. Full article

High grafting is a widely recognized technique for varietal renewal in aging citrus orchards. However, following high grafting, a specific ‘rootstock-interstock-scion’ combination is formed, yet the influence of interstock on scion fruit quality remains insufficiently explored. To address this gap, we conducted experiments by grafting ‘Yuanxiaochun’ ((Citrus unshiu Marcov × Citrus sinensis Osbeck) × (Citrus reticulata × Citrus paradisi)) onto three distinct interstocks (‘Yuanxiaochun’/‘Harumi’/‘Trifoliate orange’ (CJ), ‘Yuanxiaochun’/‘Ponkan’/‘Trifoliate orange’ (PG), ‘Yuanxiaochun’/‘Marumi Kumquat’/‘Trifoliate orange’ (JJ)), with ‘Yuanxiaochun’/‘Trifoliate orange’ used as a control (CK), and comprehensively evaluated their impact on fruit quality of ‘Yuanxiaochun’. Our research results show that interstock significantly increased the total soluble solids (TSSs) content of fruit. Additionally, interstocks also significantly increased the organic acid content in the fruit, particularly citric acid, which was on average 2.90 mg·g⁻¹ FW higher than CK. In terms of fruit flavor, interstocks significantly reduced the sugar/acid ratio and the sweetness/total acid ratio. However, CJ and PG showed markedly higher sweetness levels. Furthermore, interstocks led to a marked increase in both total amino acid content and flavor-active amino acid content in the fruit. Taste active values of γ-aminobutyric acid, asparagine, aspartic acid, glutamic acid, and arginine were all greater than 1, indicating a significant contribution to the fruit flavor. Moreover, interstocks increased the total flavonoid and phenol content in the fruit, thereby affecting its overall antioxidant capacity. These findings provide valuable and systematic insights for high grafting and variety renewal in citrus production. Full article