RESUMO
This study presents the contents of α-methylenecyclopropylglycine, a potentially toxic amino acid, in the peel, pulp and seed fractions of two well-known litchi varieties, namely Shahi and China, over a span of three harvest-seasons. For analysing α-methylenecyclopropylglycine, an LC-MS/MS-based method was validated. The method-accuracies fell within 75-110 % (RSD, <15 %) at 0.1 mg/kg (LOQ) and higher levels. A comparative evaluation of the results in peel, pulp and seed at 30 days before harvest (DBH), 15-DBH, and edible-ripe stage revealed that α-methylenecyclopropylglycine content increased as the litchi seeds grew towards maturity, regardless of the cultivar. In arils, at maturity, the concentration of α-methylenecyclopropylglycine ranged from not-detected to 11.7 µg/g dry weight. The Shahi cultivar showed slightly higher α-methylenecyclopropylglycine content in comparison to China litchi. This paper presents the first known analysis of combined seasonal data on different fruit components at various growth stages for the two chosen litchi cultivars grown in India.
Assuntos
Frutas , Litchi , Sementes , Espectrometria de Massas em Tandem , Litchi/química , Litchi/crescimento & desenvolvimento , Litchi/metabolismo , Frutas/química , Frutas/crescimento & desenvolvimento , China , Sementes/química , Sementes/crescimento & desenvolvimento , Glicina/análogos & derivados , Glicina/análise , Cromatografia Líquida de Alta Pressão , Ciclopropanos/análiseRESUMO
Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6-31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT). The Coulomb-attenuating approach (CAM-B3LYP) was utilized to obtain theoretical electronic absorption spectra with the 6-31G(d, p) basis set to be more accurate than alternative quantum chemical calculation approaches, showing good agreement with the experimental data. The TDM and FMO investigation showed that glycine/CaO model has the highest TDM (10.129Debye) and lowest band gap (1.643 eV). The DFT computed IR and the experimental FTIR are consistent. The calculated UV-vis spectra showed a red shift with an increase in polarity following an increase in the absorption wavelength due to the interaction with ZnO, MgO, and CaO. Among the five solvents of water, methanol, ethanol, DMSO and acetone, the water and DMSO enhances the UV-Vis absorption. Glycine/CaO model showed high linear polarizability (14.629 × 10-24esu) and first hyperpolarizability (23.117 × 10-30esu), indicating its potential for nonlinear optical applications. The results showed that all model molecules, particularly glycine/CaO, contribute significantly to the development of materials with potential NLO features for sensor and optoelectronic applications. Additionally, MESP confirmed the increased electronegativity of the studied structures. Additionally, glycine/ZnO nanocomposite was synthesized and characterized using IR and UV-visible spectroscopy to determine their structural and spectroscopic features. It was discovered that there was good agreement between the DFT computed findings and the related experimental data. The antibacterial activity of glycine/ZnO nanocomposites against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa were studied in terms of concentration and time. The results showed that increasing the concentration of glycine/ZnO nanocomposite significantly enhanced its antibacterial efficacy by lowering optical density. Notably, Pseudomonas aeruginosa exhibited lower susceptibility to the nanocomposite compared to S. aureus, requiring higher concentrations for effective bactericidal action. In summary, this study contributes novel insights into the dual functionality of glycine-metal oxide complexes, with significant implications as optical biosensor for microbial detection.
Assuntos
Compostos de Cálcio , Glicina , Óxido de Magnésio , Óxidos , Óxido de Zinco , Óxido de Zinco/química , Óxido de Magnésio/química , Óxidos/química , Glicina/química , Compostos de Cálcio/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Teoria da Densidade Funcional , Bactérias , Eletricidade EstáticaRESUMO
The emission of glyphosate and antibiotic residues from human activities threatens the diversity and functioning of the microbial community. This study examines the impact of a glyphosate-based herbicide (GBH) and common antibiotics on Gram-negative bacteria within the ESKAPEE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli). Ten strains, including type and multidrug-resistant strains for each species were analysed and eight antibiotics (cefotaxime, meropenem, aztreonam, ciprofloxacin, gentamicin, tigecycline, sulfamethoxazole-trimethoprim, and colistin) were combined with the GBH. While most combinations yielded additive or indifferent effects in 70 associations, antagonistic effects were observed with ciprofloxacin and gentamicin in five strains. GBH notably decreased the minimum inhibitory concentration of colistin in eight strains and displayed synergistic activity with meropenem against metallo-ß-lactamase (MBL)-producing strains. Investigation into the effect of GBH properties on outer membrane permeability involved exposing strains to a combination of this GBH and vancomycin. Results indicated that GBH rendered strains sensitive to vancomycin, which is typically ineffective against Gram-negative bacteria. Furthermore, we examined the impact of GBH in combination with three carbapenem agents on 14 strains exhibiting varying carbapenem-resistance mechanisms to assess its effect on carbapenemase activity. The GBH efficiently inhibited MBL activity, demonstrating similar effects to EDTA (ethylenediaminetetraacetic acid). Chelating effect of GBH may have multifaceted impacts on bacterial cells, potentially by increasing outer membrane permeability and inactivating metalloenzyme activity.
Assuntos
Acinetobacter baumannii , Antibacterianos , Glicina , Glifosato , Bactérias Gram-Negativas , Herbicidas , Testes de Sensibilidade Microbiana , Glicina/análogos & derivados , Glicina/farmacologia , Antibacterianos/farmacologia , Herbicidas/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Acinetobacter baumannii/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Humanos , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Ciprofloxacina/farmacologia , Enterococcus faecium/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Colistina/farmacologia , Vancomicina/farmacologia , Enterobacter/efeitos dos fármacos , Sinergismo Farmacológico , Meropeném/farmacologia , Fenótipo , Gentamicinas/farmacologiaRESUMO
BACKGROUND: To minimize the impact of pesticide residues in food on human health, it is necessary to enhance their detection. Recently, many nanozyme-based colorimetric methods for pesticides detection have been developed, however, they often required the assistance of natural enzymes, which made the process and result of methods susceptible to the stability and activity of natural enzymes. To overcome these drawbacks, methods for direct detection of pesticides using nanozymes have been developed, and there are few studies in this field currently. Thus, it is of great research and practical significance to develop more nanozymes-based colorimetric methods for direct detection of pesticides. RESULTS: Dual colorimetric platforms based on Os-Rh nanozyme with excellent peroxidase-like activity were constructed for directly detection of glyphosate in this work. Results showed that glyphosate was able to sensitively and selectively inhibit the peroxidase-like activity of Os-Rh nanozyme through hindering the decomposition of H2O2 by Os-Rh nanozyme to produce HOâ. Based on this, the dual colorimetric platforms achieved highly sensitive detection for glyphosate over a wide linear concentration range (50-1000 µg L-1 in solution platform and 200-1000 µg L-1 in paper platform), with the detection limits of 28.37 µg L-1 in solution platform and 400 µg L-1 (naked-eye detection limit)/123.25 µg L-1 (gray scale detection limit) in paper platform, respectively. Moreover, the dual colorimetric platforms possessed satisfactory reliability and accuracy for practical applications, and has been successfully applied to the detection of real samples with the spiked recoveries of 92.78-102.75 % and RSD of 1.17-3.88 %. SIGNIFICANCE: The dual colorimetric platforms for glyphosate direct detection based on Os-Rh nanozyme developed in this work not only owned considerable practical application potential, but also could provide more inspirations and ideas for the rational design and development of colorimetric sensing methods for the rapid detection of pesticides based on nanozymes.
Assuntos
Colorimetria , Glicina , Glifosato , Colorimetria/métodos , Glicina/análogos & derivados , Glicina/análise , Glicina/química , Peroxidase/metabolismo , Peroxidase/química , Limite de Detecção , Peróxido de Hidrogênio/químicaRESUMO
Spiders are important in ecosystem and serve as predators in the biological control of pest insects in agroecosystem, where they encounter various harsh challenges including pesticides and low temperature in winter. Glyphosate-based herbicides (GBH) are widely and frequently applied to diminish weeds, exposing spiders a disturbed habitat, especially to overwintering spiders. We conducted a study combining field surveys and lab assays, to assess the effects of a GBH on the overwintering of the agrobiont wolf spider, Pardosa pseudoannulata. The GBH significantly reduced the overall overwintering spider population by about 69 %, and reduced the number of vulnerable juveniles by about 80 %. The survivors exhibited substantial fitness costs such as reproductive dysfunctions and enhanced oxidative stress responses. We then mimicked the overwinter process in lab. We housed spiders on soil patches with and without weeds to examine whether weeds contributed to the GBH's sublethal effects. Spiders overwintered independent of weeds when GBH was not applied. When GBH was applied before or during overwintering, juvenile spiders overwintered in weedy habitats exhibited reduced survival and fecundity, and increased oxidative stress compared to their counterparts in weed-free habitats. Therefore, GBH-containing weeds contributed to the persistent adverse effects of GBH on overwintering spiders. The findings revealed the cross-talk among weeds, herbicides, low temperature, and non-target organisms. The study provides novel information on the environmental risk assessment of pesticides and rational scheduling of pesticide application.
Assuntos
Glicina , Glifosato , Herbicidas , Reprodução , Estações do Ano , Aranhas , Animais , Aranhas/efeitos dos fármacos , Herbicidas/toxicidade , Glicina/análogos & derivados , Glicina/toxicidade , Reprodução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Plantas Daninhas/efeitos dos fármacos , FemininoRESUMO
The purpose of this paper was to study in vitro atomization properties of the self-developed sodium sivelestat for inhalation, evaluate the feasibility of this preparation as an aerosol inhalation, and provide the guidance for the following animal administration experiment. Firstly, in order to ensure accurate, uniform and stable doses of the self-developed product after administration, its atomization performance was analyzed through the testing of fine particle mass and the total emitted dose, and the results of its atomization parameters meet the requirement of inhalation. Next, Atomization characteristics of two commonly used nebulizers, air compressed nebulizer and mesh nebulizer, were studied and compared. The results showed that mesh atomizers have a smaller and more uniform particle size distribution. And then, the experiment of acute lung injury induced by aerosol inhalation of lipopolysaccharide in mice was used to test the therapeutic effect of our self-developed formulation, and compared with the positive control (sodium sivelestat for injection). The results showed that inhalation had a lower concentration and was equally effective than injection of sodium sivelestat. All the results support that the self-developed sodium sivelestat can be used as an aerosol inhaled drug.
Assuntos
Aerossóis , Glicina , Nebulizadores e Vaporizadores , Tamanho da Partícula , Sulfonamidas , Animais , Administração por Inalação , Camundongos , Sulfonamidas/administração & dosagem , Glicina/análogos & derivados , Glicina/administração & dosagem , Glicina/química , Lesão Pulmonar Aguda/tratamento farmacológico , MasculinoRESUMO
Microplastics represent a novel category of environmental pollutants, and understanding their interactions with typical xenobiotics is crucial. In this study, we investigated the impact of ionic liquids (ILs) containing herbicidal anions, namely glyphosate [Glyph] and 2,4-dichlorophenoxyacetate [2,4-D], and the surfactant cation - dodecyltrimethylammonium [C12TMA] on acrylonitrile butadiene styrene (ABS) microplastics. The aim of the study was to assess the sorption capacity of microplastics that were present in both untreated and aged form using standard and modified Fenton methods. In addition, impact on toxicity and stress adaptation of the model soil bacterium Pseudomonas putida KT2440 was measured. Upon ageing, ABS microplastics underwent a fivefold increase in BET surface area and total pore volume (from 0.001 to 0.004 cm3/g) which lead to a dramatic increase in adsorption of the cations on ABS microplastics from 40 to 45% for virgin ABS to 75-80% for aged ABS. Toxicity was mainly attributed to hydrophobic cations in ILs (EC50 â¼ 60-65 mg/dm3), which was also mitigated by sorption on ABS. Furthermore, both cations and anions behaved similarly across different ILs, corresponding chlorides, and substrates used in the ILs synthesis. These findings highlight microplastics potential as hazardous sorbents, contributing to the accumulation of xenobiotics in the environment.
Assuntos
Ácido 2,4-Diclorofenoxiacético , Butadienos , Glicina , Glifosato , Herbicidas , Líquidos Iônicos , Microplásticos , Herbicidas/toxicidade , Herbicidas/química , Herbicidas/análise , Microplásticos/toxicidade , Adsorção , Ácido 2,4-Diclorofenoxiacético/toxicidade , Ácido 2,4-Diclorofenoxiacético/química , Líquidos Iônicos/toxicidade , Líquidos Iônicos/química , Glicina/análogos & derivados , Glicina/toxicidade , Glicina/química , Butadienos/toxicidade , Butadienos/química , Acrilonitrila/toxicidade , Acrilonitrila/química , Pseudomonas putida/efeitos dos fármacos , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Poluentes do Solo/química , Resinas Acrílicas , PoliestirenosRESUMO
Glycine receptors (GlyR) conduct inhibitory glycinergic neurotransmission in the spinal cord and the brainstem. They play an important role in muscle tone, motor coordination, respiration, and pain perception. However, the mechanism underlying GlyR activation remains unclear. There are five potential glycine binding sites in α1 GlyR, and different binding patterns may cause distinct activation or desensitization behaviors. In this study, we investigated the coupling of protein conformational changes and glycine binding events to elucidate the influence of binding patterns on the activation and desensitization processes of α1 GlyRs. Subsequently, we explored the energetic distinctions between the apical and lateral pathways during α1 GlyR conduction to identify the pivotal factors in the ion conduction pathway preference. Moreover, we predicted the mutational effects of the key residues and verified our predictions using electrophysiological experiments. For the mutants that can be activated by glycine, the predictions of the mutational directions were all correct. The strength of the mutational effects was assessed using Pearson's correlation coefficient, yielding a value of -0.77 between the calculated highest energy barriers and experimental maximum current amplitudes. These findings contribute to our understanding of GlyR activation, identify the key residues of GlyRs, and provide guidance for mechanistic studies on other pLGICs.
Assuntos
Glicina , Receptores de Glicina , Receptores de Glicina/metabolismo , Receptores de Glicina/química , Humanos , Glicina/química , Glicina/metabolismo , Sítios de Ligação , Mutação , Conformação Proteica , Modelos MolecularesRESUMO
Herbicide exposure can pose a considerable threat to non-target aquatic animals. We aimed to study changes in the liver proteome of a model cyprinid fish species, zebrafish Danio rerio, to provide a molecular basis for the adverse effects of environmentally relevant concentrations of glyphosate (100 µg/L), its breakdown product aminomethylphosphonic acid (AMPA; 100 µg/L), and a mixture of both (50 + 50 µg/L) in the presence of humic acid (20 mg/L), which simulated a component of natural organic matter in the aquatic environment. Proteomic analysis was performed by means of high-performance liquid chromatography-tandem mass spectrometry employing a label-free quantification approach. The results present molecular evidence of the stress responses and disturbance of primary metabolic processes such as immune response, dysregulation in DNA repair, necroptosis and apoptosis signaling pathways, oxidative phosphorylation, cholesterol, lipoprotein, and carbohydrate metabolism. We registered the synergistic effect of the glyphosate and AMPA co-exposure, which was expressed in a substantial increase in the number of dysregulated proteins compared to the solo treatments. Humic acid alleviated the effects of glyphosate and its mixture with AMPA and aggravated the impact of AMPA exposure. RuvB-like 2, a protein taking part in DNA repair, and EIF2S1, involved in the regulation of stress-induced gene expression, were downregulated in the liver of zebrafish from all treatments.
Assuntos
Glicina , Glifosato , Herbicidas , Substâncias Húmicas , Fígado , Proteoma , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Glicina/análogos & derivados , Glicina/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Proteoma/metabolismo , Proteoma/efeitos dos fármacos , Herbicidas/toxicidade , Organofosfonatos/toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
Glyphosate (GLY), the most widely used herbicide, has been regarded as an emergent environmental contaminant due to its constant and cumulative use, with potential harm to non-target organisms, such as crops, disrupting cells' redox balance. Therefore, plants need to fine-tune their antioxidant (AOX) mechanisms to thrive under GLY-contaminated environments. Proline overaccumulation is a common response in plants exposed to GLY, yet its role in GLY-induced toxicity remains unclear. Thus, this study explores whether Pro overaccumulation in response to GLY is perceived as a downstream tolerance mechanism or an early-warning stress signal. To investigate this, Arabidopsis thaliana T-DNA mutant lines for Pro biosynthetic (P5CS1) and catabolic genes (ProDH) were used and screened for their GLY susceptibility. Upon seedlings' exposure to GLY (0.75 mg L-1) for 14 days, the herbicide led to reduced biomass in all genotypes, accompanied by Pro overaccumulation. Mutants with heightened Pro levels (prodh) exhibited the greatest biomass reduction, increased lipid peroxidation (LP), and hydrogen peroxide (H2O2) levels, accompanied by a compromised performance of the AOX system. Conversely, p5cs1-4, mutants with lower Pro levels, demonstrated an enhanced AOX system activation, not only with increased levels of glutathione (GSH) and ascorbate (AsA), but also with increased activity of both ascorbate peroxidase (APX) and catalase (CAT). These findings suggest that Pro overaccumulation under GLY exposure is associated with stress sensitivity rather than tolerance, highlighting its potential as an early-warning signal for GLY toxicity in non-target plants and for detecting weed resistance.
Assuntos
Arabidopsis , Glicina , Glifosato , Herbicidas , Prolina , Glicina/análogos & derivados , Glicina/farmacologia , Glicina/toxicidade , Prolina/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Herbicidas/toxicidade , Herbicidas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Antioxidantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/fisiologia , Plântula/metabolismoRESUMO
The nuclear pore complex (NPC) is a critical gateway regulating molecular transport between the nucleus and cytoplasm. It allows small molecules to pass freely, while larger molecules require nuclear transport receptors to traverse the barrier. This selective permeability is maintained by phenylalanine-glycine-rich nucleoporins (FG-Nups), intrinsically disordered proteins that fill the NPC's central channel. The disordered and flexible nature of FG-Nups complicates their spatial characterization with conventional structural biology techniques. To address this challenge, polymer physics offers a valuable framework for describing FG-Nup behavior, reducing their complex structures to a few key parameters. In this review, we explore how polymer physics models FG-Nups using these parameters and discuss experimental efforts to quantify them in various contexts, providing insights into the conformational properties of FG-Nups.
Assuntos
Proteínas Intrinsicamente Desordenadas , Complexo de Proteínas Formadoras de Poros Nucleares , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/química , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Humanos , Polímeros/química , Polímeros/metabolismo , Animais , Poro Nuclear/metabolismo , Poro Nuclear/química , Fenilalanina/química , Fenilalanina/metabolismo , Glicina/metabolismo , Glicina/químicaRESUMO
The global decline of pollinators has become a major concern for the scientific community, policymakers, and the general public. Among the main drivers of diminishing bee populations is the widespread use of agrochemicals. To gain a comprehensive understanding of the foraging dynamics of bees at agrochemical-contaminated areas, it is essential to consider both environmental conditions and the specific foraging ecology of bee species. For the first time, we conducted a semi-field study to investigate whether stingless bees exhibit a preference for food contaminated with agrochemicals compared to non- contaminated food, under natural weather conditions. Colonies of Plebeia lucii Moure, 2004 were placed in a greenhouse and subjected to a preference test, where bees were given the freedom to choose between contaminated or non-contaminated food sources following a preliminary training period. Within the greenhouse, we placed feeders containing realistic concentrations of an insecticide (acephate: 2 mg a.i./L), a herbicide (glyphosate: 31.3 mg a.i./L), or a mixture of both, alongside non-contaminated food. Environmental variables (temperature, humidity, and light intensity) were monitored throughout the experiment. At higher temperatures, the foragers preferred food containing the mixture of both agrochemicals or uncontaminated food over the other treatments. At lower temperatures, by contrast, the bees preferred food laced with a single agrochemical (acephate or glyphosate) over uncontaminated food or the agrochemical mixture. Our findings indicate that agrochemical residues in nectar pose a significant threat to P. lucii colonies, as foragers do not actively avoid contaminated food, despite the detrimental effects of acephate and glyphosate on bees. Furthermore, we demonstrate that even minor, natural fluctuations in environmental conditions can alter the colony exposure risk. Despite the interplay between temperature and bees' preference for contaminated food, foragers consistently collected contaminated food containing both agrochemicals, whether isolated or in combination, throughout the whole experiment.
Assuntos
Glicina , Glifosato , Herbicidas , Animais , Abelhas/fisiologia , Glicina/análogos & derivados , Glicina/toxicidade , Inseticidas/toxicidade , Contaminação de AlimentosRESUMO
Dissolved organic matter (DOM) is easy to combine with residual pesticides and affect their morphology and environmental behavior. Given that the binding mechanism between DOM and the typical herbicide glyphosate in soil is not yet clear, this study used adsorption experiments, multispectral techniques, density functional theory, and pot experiments to reveal the interaction mechanism between DOM and glyphosate on Mollisol in farmland and their impact on the environment. The results show that the adsorption of glyphosate by Mollisol is a multilayer heterogeneous chemical adsorption process. After adding DOM, due to the early formation of DOM and glyphosate complex, the adsorption process gradually became dominated by single-layer chemical adsorption, and the adsorption capacity increased by 1.06 times. Glyphosate can quench the endogenous fluorescence of humic substances through a static quenching process dominated by hydrogen bonds and van der Waals forces, and instead enhance the fluorescence intensity of protein substances by affecting the molecular environment of protein molecules. The binding of glyphosate to protein is earlier, of which affinity stronger than that of humic acid. In this process, two main functional groups (C-O in aromatic groups and C-O in alcohols, ethers and esters) exist at the binding sites of glyphosate and DOM. Moreover, the complexation of DOM and glyphosate can effectively alleviate the negative impact of glyphosate on the soil. This study has certain theoretical guidance significance for understanding the environmental behavior of glyphosate and improving the sustainable utilization of Mollisol.
Assuntos
Glicina , Glifosato , Herbicidas , Substâncias Húmicas , Poluentes do Solo , Glicina/análogos & derivados , Glicina/química , Adsorção , Herbicidas/química , Poluentes do Solo/química , Fazendas , Espectrometria de FluorescênciaRESUMO
Guanidinoacetic acid, as an energetic substance, has a wide range of applications in the food, pharmaceutical, and feed industries. However, the biosynthesis of guanidinoacetic acid has not been applied in industrial production. In this study, we designed the synthetic route of guanidinoacetic acid in a food-grade strain of Bacillus subtilis. By regulating the expression of key enzymes, lifting feedback inhibition, and increasing membrane permeability, we achieved the efficient synthesis of guanidinoacetic acid by whole-cell catalysis. Firstly, the optimal L-arginine:glycine amidinotransferase was screened based on the phylogenetic tree, and the expression of the key enzyme was enhanced by a strategy combining strong promoter and genome integration. Secondly, the ornithine cycle for L-arginine synthesis in Corynebacterium glutamicum was introduced to alleviate the feedback inhibition of the enzyme by the byproduct L-ornithine, and the L-arginine degradation pathway was knocked down to enhance substrate regeneration. Thirdly, the expression of N-acetylmuramoyl-L-alanine amidase (LytC) was up-regulated to increase the cell membrane permeability. Finally, after optimization of whole-cell production conditions, strain Bs-13 achieved guanidinoacetic acid production at a titer of 13.1 g/L after 24 h, with a proudction rate of 0.54 g/(L·h) and a glycine conversion rate of 92.7%. The above strategy improved the production of guanidinoacetic acid and provided a reference for the biosynthesis of guanidinoacetic acid.
Assuntos
Arginina , Bacillus subtilis , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Arginina/biossíntese , Arginina/metabolismo , Glicina/análogos & derivados , Glicina/metabolismo , Glicina/biossíntese , Amidinotransferases/genética , Amidinotransferases/metabolismo , Corynebacterium glutamicum/metabolismo , Corynebacterium glutamicum/genética , N-Acetil-Muramil-L-Alanina Amidase/genética , N-Acetil-Muramil-L-Alanina Amidase/metabolismo , Engenharia Metabólica , Ornitina/biossíntese , Ornitina/metabolismoRESUMO
Glyphosate, the active ingredient in many herbicides, has been widely used in agriculture since the 1970s. Despite initial beliefs in its safety for humans and animals due to the absence of the shikimate pathway, recent studies have raised concerns about its potential health effects. This study aimed to identify glycomic changes indicative of glyphosate-induced toxicity. Specifically, the study focused on profiling N-glycosylation, a protein post-translational modification increasingly recognized for its involvement in various disorders, including neurological conditions. A comprehensive analysis of rat serum N-glycomics following chronic exposure to glyphosate-based herbicides (GBH) was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results revealed significant changes in the N-glycan profile, particularly in sialylated and sialofucosylated N-glycans. The analysis of N-glycans across gender subgroups provided insights into gender-specific responses to GBH exposure, with the male rats exhibiting a higher susceptibility to these N-glycan changes compared to females. The validation of significantly altered N-glycans using parallel reaction monitoring (PRM) confirmed their expression patterns. This study provides novel insights into the impact of chronic GBH exposure on serum N-glycan composition, with implications for assessing glyphosate toxicity and its potential neurological implications.
Assuntos
Glicina , Glifosato , Herbicidas , Polissacarídeos , Animais , Glicina/análogos & derivados , Glicina/toxicidade , Glicina/sangue , Herbicidas/toxicidade , Ratos , Masculino , Feminino , Glicosilação/efeitos dos fármacos , Glicômica , Espectrometria de Massas em Tandem , Ratos Sprague-Dawley , Cromatografia LíquidaRESUMO
BACKGROUND AND OBJECTIVE: Daprodustat is a first-in-class hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) approved in the USA for treatment of anemia owing to chronic kidney disease (CKD) in dialysis-dependent adults and in Japan for treatment of CKD in dialysis- and non-dialysis dependent adults. This analysis characterized the population pharmacokinetics (PopPK) of daprodustat in adults with CKD and evaluated the influence of intrinsic and extrinsic factors. METHODS: This PopPK analysis included data from one phase 2B and four phase 3 studies comprising 707 CKD subjects dose titrated to prespecified target hemoglobin levels with daprodustat doses ranging from 1 to 24 mg once daily and 2 to 48 mg given three times a week (TIW). Model development leveraged a previous phase 1/2 PopPK model. Stepwise covariate analysis included 20 extrinsic and intrinsic factors. Model evaluation used standard goodness-of-fit and visual predictive checks. RESULTS: Daprodustat PopPK was adequately characterized using a three-compartment distribution model with first-order elimination. The absorption phase was described using five transit compartments. Oral clearance and volume of distribution was 24.6 L/h and 26.9 L, respectively. Body weight dependence (with fixed allometric coefficients) of clearance and volume terms was a statistically significant covariate. Concomitant use of clopidogrel (moderate CYP2C8 inhibitor) decreased oral clearance, resulting in higher area under the plasma concentration-time curve (AUC) ratio of 1.59 (90% CI: 1.39-1.82), subjects' dialysis status (non-dialysis versus dialysis) had an effect on absorption, with Cmax ratio of 1.19 (90% CI: 1.09-1.30). None of the other investigated intrinsic or extrinsic covariates, including concomitant administration with phosphate binders, oral iron and acid reducing agents resulted in a significant change in daprodustat systemic exposure. CONCLUSION: The PopPK of daprodustat in the CKD population with anemia was adequately characterized. Allometrically-scaled body weight on clearance and volume, dialysis status on absorption and clopidogrel on clearance were statistically significant covariates.
Assuntos
Anemia , Glicina , Modelos Biológicos , Insuficiência Renal Crônica , Humanos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/metabolismo , Masculino , Anemia/tratamento farmacológico , Anemia/sangue , Feminino , Pessoa de Meia-Idade , Glicina/análogos & derivados , Glicina/farmacocinética , Glicina/administração & dosagem , Idoso , Adulto , Idoso de 80 Anos ou mais , Quinoxalinas/farmacocinética , Quinoxalinas/administração & dosagem , Prolina Dioxigenases do Fator Induzível por Hipóxia/antagonistas & inibidores , Adulto Jovem , Barbitúricos/farmacocinética , Barbitúricos/administração & dosagem , Inibidores de Prolil-Hidrolase/farmacocinética , Inibidores de Prolil-Hidrolase/administração & dosagemRESUMO
Terahertz (THZ) spectroscopy has emerged as a superior label-free sensing technology in the detection, identification, and quantification of biomolecules in various biological samples. However, the limitations in identification and discrimination sensitivity of current methods impede the wider adoption of this technology. In this article, a meticulously designed metasurface is proposed for molecular fingerprint enhancement, consisting of a periodic array of lithium tantalate triangular prism tetramers arranged in a square quartz lattice. The physical mechanism is explained by the finite-difference time-domain (FDTD) method. The metasurface achieves a high quality factor (Q-factor) of 231 and demonstrates excellent THz sensing capabilities with a figure of merit (FoM) of 609. By varying the incident angle of the THz wave, the molecular fingerprint signal is strengthened, enabling the highly sensitive detection of trace amounts of analyte. Consequently, cinnamoylglycine can be detected with a sensitivity limit as low as 1.23 µg·cm-2. This study offers critical insights into the advanced application of THz waves in biomedicine, particularly for the detection of urinary biomarkers in various diseases, including gestational diabetes mellitus (GDM).
Assuntos
Técnicas Biossensoriais , Glicina , Espectroscopia Terahertz , Glicina/análogos & derivados , Humanos , Limite de DetecçãoRESUMO
This study investigated the effects of herbicide exposure on Navicula sp. (MASCC-0035) algae, focusing on growth density, chlorophyll content, antioxidant system, and lipid metabolism. Navicula cultures were exposed to different concentrations of atrazine (ATZ), glyphosate (Gly), and acetochlor (ACT) for 96 h. Results showed a significant decrease in cell numbers, with higher herbicide concentrations having the most noticeable impacts. For instance, Gly-G2 had reduced cell populations by 21.00% at 96 h. Chlorophyll content varied, with Gly having a greater impact on chlorophyll a compared to ATZ and ACT. Herbicide exposure also affected the antioxidant system, altering levels of soluble sugar, soluble protein, and reactive oxygen species (ROS). Higher herbicide rates increased soluble sugar content (e.g., ATZ, Gly, and ACT-G2 had increased by 14.03%, 19.88%, and 19.83%, respectively, at 72 h) but decreased soluble protein content, notably in Gly-G2 by 11.40%, indicating cellular stress. Lipid metabolism analysis revealed complex responses, with changes in free proline, fatty acids, and lipase content, each herbicide exerting distinct effects. These findings highlight the multifaceted impacts of herbicide exposure on Navicula algae, emphasizing the need for further research to understand ecological implications and develop mitigation strategies for aquatic ecosystems.
Assuntos
Antioxidantes , Clorofila , Glicina , Glifosato , Herbicidas , Metabolismo dos Lipídeos , Herbicidas/toxicidade , Clorofila/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Glicina/análogos & derivados , Glicina/toxicidade , Atrazina/toxicidade , Poluentes Químicos da Água/toxicidade , Espécies Reativas de Oxigênio/metabolismo , ToluidinasRESUMO
It is not known why the number of proteinogenic amino acids is limited to 20. Since Miller's experiment, many studies have shown that amino acids could have been generated under prebiotic conditions. However, the amino acid compositions obtained from simulated experiments and exogenous origins are different from those of life. We hypothesized that some simple precursor compounds generated by high-energy reactions were selectively combined by organic reactions to afford a limited number of amino acids. To this direction, we propose two scenarios. One is the reaction of HCN with each side-chain precursor (the aminomalononitrile scenario), and the other is alkylation of the "complex glycine precursor", which is the main product of proton irradiation of the primordial atmosphere (the new polyglycine scenario). Here, selective formation of the 20 amino acids is described focusing on the latter scenario. The structural features of proteinogenic amino acids can be described systematically. The scenario consists of three stages: a high-energy reaction stage (Gly, Ala, Asn, and Asp were established); an alkylation stage (Gln, Glu, Ser, Thr, Val, Ile, Leu, and Pro were generated in considerable amounts); and a peptide formation stage (Phe, Tyr, Trp, His, Lys, Arg, Cys, and Met were selected due to their structural advantages). This scenario is a part of the evolution of Garakuta World, in which many prebiotic materials are contained.
Assuntos
Aminoácidos , Glicina , Glicina/química , Alquilação , Aminoácidos/química , Origem da Vida , Peptídeos/químicaRESUMO
Assessment of personal formaldehyde (FA) exposure is most commonly carried out using formate as a biomarker, as it is the major product from FA metabolism. However, formate could also have originated from the metabolism of other endogenous and exogenous substances or from dietary intake, which may give rise to overestimated results with regard to FA exposure. We have developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with an isotope-dilution method for rigorous quantitation of two major urinary FA conjugation products: thioproline (SPro) and thioprolinyl glycine (SPro-Gly), formed in the reaction between FA and endogenous cysteine or cysteinyl glycine, respectively, as marker molecules to assess personal FA exposure. Using this newly developed method, we measured the FA exposure levels in cigarette smokers, occupants of a chemistry research laboratory and typical domestic household, and visitors to a Chinese temple with a Pearson correlation coefficient greater than 0.94, showing a strong linear correlation between urinary adduct levels and the airborne FA level. It is believed that quantitation of urinary SPro and SPro-Gly may represent a noninvasive, interference-free method for assessing personal FA exposure.