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1.
PeerJ ; 12: e17462, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38827302

RESUMO

Cytokinin oxidase/dehydrogenase (CKX), responsible for irreversible cytokinin degradation, also controls plant growth and development and response to abiotic stress. While the CKX gene has been studied in other plants extensively, its function in cotton is still unknown. Therefore, a genome-wide study to identify the CKX gene family in the four cotton species was conducted using transcriptomics, quantitative real-time PCR (qRT-PCR) and bioinformatics. As a result, in G. hirsutum and G. barbadense (the tetraploid cotton species), 87 and 96 CKX genes respectively and 62 genes each in G. arboreum and G. raimondii, were identified. Based on the evolutionary studies, the cotton CKX gene family has been divided into five distinct subfamilies. It was observed that CKX genes in cotton have conserved sequence logos and gene family expansion was due to segmental duplication or whole genome duplication (WGD). Collinearity and multiple synteny studies showed an expansion of gene families during evolution and purifying selection pressure has been exerted. G. hirsutum CKX genes displayed multiple exons/introns, uneven chromosomal distribution, conserved protein motifs, and cis-elements related to growth and stress in their promoter regions. Cis-elements related to resistance, physiological metabolism and hormonal regulation were identified within the promoter regions of the CKX genes. Expression analysis under different stress conditions (cold, heat, drought and salt) revealed different expression patterns in the different tissues. Through virus-induced gene silencing (VIGS), the GhCKX34A gene was found to improve cold resistance by modulating antioxidant-related activity. Since GhCKX29A is highly expressed during fibre development, we hypothesize that the increased expression of GhCKX29A in fibres has significant effects on fibre elongation. Consequently, these results contribute to our understanding of the involvement of GhCKXs in both fibre development and response to abiotic stress.


Assuntos
Regulação da Expressão Gênica de Plantas , Gossypium , Oxirredutases , Estresse Fisiológico , Gossypium/genética , Estresse Fisiológico/genética , Oxirredutases/genética , Oxirredutases/metabolismo , Fibra de Algodão , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Família Multigênica , Filogenia , Genoma de Planta/genética
2.
Biochemistry (Mosc) ; 89(4): 701-710, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38831506

RESUMO

Many microorganisms are capable of anaerobic respiration in the absence of oxygen, by using different organic compounds as terminal acceptors in electron transport chain. We identify here an anaerobic respiratory chain protein responsible for acrylate reduction in the marine bacterium Shewanella woodyi. When the periplasmic proteins of S. woodyi were separated by ion exchange chromatography, acrylate reductase activity copurified with an ArdA protein (Swoo_0275). Heterologous expression of S. woodyi ardA gene (swoo_0275) in Shewanella oneidensis MR-1 cells did not result in the appearance in them of periplasmic acrylate reductase activity, but such activity was detected when the ardA gene was co-expressed with an ardB gene (swoo_0276). Together, these genes encode flavocytochrome c ArdAB, which is thus responsible for acrylate reduction in S. woodyi cells. ArdAB was highly specific for acrylate as substrate and reduced only methacrylate (at a 22-fold lower rate) among a series of other tested 2-enoates. In line with these findings, acrylate and methacrylate induced ardA gene expression in S. woodyi under anaerobic conditions, which was accompanied by the appearance of periplasmic acrylate reductase activity. ArdAB-linked acrylate reduction supports dimethylsulfoniopropionate-dependent anaerobic respiration in S. woodyi and, possibly, other marine bacteria.


Assuntos
Acrilatos , Shewanella , Shewanella/enzimologia , Shewanella/genética , Shewanella/metabolismo , Transporte de Elétrons , Acrilatos/metabolismo , Anaerobiose , Oxirredutases/metabolismo , Oxirredutases/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética
3.
Sci Rep ; 14(1): 12753, 2024 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830975

RESUMO

Six Transmembrane Epithelial Antigen of Prostate 2 (STEAP2) belongs to a family of metalloreductases, which indirectly aid in uptake of iron and copper ions. Its role in hepatocellular carcinoma (HCC) remains to be characterized. Here, we report that STEAP2 expression was upregulated in HCC tumors compared with paired adjacent non-tumor tissues by RNA sequencing, RT-qPCR, Western blotting, and immunostaining. Public HCC datasets demonstrated upregulated STEAP2 expression in HCC and positive association with tumor grade. Transient and stable knockdown (KD) of STEAP2 in HCC cell lines abrogated their malignant phenotypes in vitro and in vivo, while STEAP2 overexpression showed opposite effects. STEAP2 KD in HCC cells led to significant alteration of genes associated with extracellular matrix organization, cell adhesion/chemotaxis, negative enrichment of an invasiveness signature gene set, and inhibition of cell migration/invasion. STEAP2 KD reduced intracellular copper levels and activation of stress-activated MAP kinases including p38 and JNK. Treatment with copper rescued the reduced HCC cell migration due to STEAP2 KD and activated p38 and JNK. Furthermore, treatment with p38 or JNK inhibitors significantly inhibited copper-mediated cell migration. Thus, STEAP2 plays a malignant-promoting role in HCC cells by driving migration/invasion via increased copper levels and MAP kinase activities. Our study uncovered a novel molecular mechanism contributing to HCC malignancy and a potential therapeutic target for HCC treatment.


Assuntos
Carcinoma Hepatocelular , Movimento Celular , Cobre , Neoplasias Hepáticas , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Cobre/metabolismo , Linhagem Celular Tumoral , Animais , Regulação Neoplásica da Expressão Gênica , Camundongos , Progressão da Doença , Masculino , Oxirredutases/metabolismo , Oxirredutases/genética , Feminino
4.
Mikrochim Acta ; 191(7): 368, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38833176

RESUMO

A colorimetric analysis platform has been successfully developed based on FeCo-NC dual-atom nanozyme (FeCo-NC DAzyme) for the detection of organophosphorus pesticides (OPPs). The FeCo-NC DAzyme exhibited exceptional oxidase-like activity (OXD), enabling the catalysis of colorless TMB to form blue oxidized TMB (oxTMB) without the need for H2O2 involvement. By combining acid phosphatase (ACP) hydrolase with FeCo-NC DAzyme, a "FeCo-NC DAzyme + TMB + ACP + SAP" colorimetric system was constructed, which facilitated the rapid detection of malathion. The chromogenic system was applied to detect malathion using a smartphone-based app and an auxiliary imaging interferogram device for colorimetric measurements, which have a linear range of 0.05-4.0 µM and a limit of detection (LOD) as low as 15 nM in real samples, comparable to UV-Vis and HPLC-DAD detection methods. Overall, these findings present a novel approach for convenient, rapid, and on-site monitoring of OPPs.


Assuntos
Colorimetria , Limite de Detecção , Praguicidas , Smartphone , Colorimetria/métodos , Praguicidas/análise , Compostos Organofosforados/análise , Compostos Organofosforados/química , Malation/análise , Malation/química , Oxirredutases/química , Ferro/química , Fosfatase Ácida/análise , Fosfatase Ácida/química , Benzidinas
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 319: 124559, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38830331

RESUMO

In this work, we present a novel colorimetric sensing platform for the sensitive detection of ethamsylate (ETM) usingultrathin MnO2 nanosheets with enhancedoxidase-mimicking activity. A facile template-free hydrothermal process was applied to synthesize the MnO2 nanosheets under mild conditions. The nanosheets exhibited oxidase-mimicking activity, facilitating the conversion of TMB into the blue-colored oxTMB in the absence of H2O2. However, the presence of ETM inhibited this activity, resulting in the conversion of oxTMB back to colorless TMB and a substantial decrease in the blue color intensity. The colorimetric response exhibited a linear relationship with ETM concentration over the range of 0.5 to 10.0 µg/mL and a detection limit of 0.156 µg/mL. To further elucidate the underlying mechanism, we performed extensive characterization and kinetic experiments. The findings demonstrated that this unique property is attributed to the remarkable capacity of the MnO2 nanosheets to absorb oxygen, producing superoxide radicals (O2-). The oxidase-mimicking activity of the nanosheets was further confirmed by the reaction kinetics, following Michaelis-Menten's behavior. Moreover, the applicability of the sensing platform was assessed by determining ETM concentrations in various real samples (different pharmaceuticals, human plasma, and environmental water). The well-established platform demonstrates the prospective role that nanomaterials-based sensing platforms may play in clinical diagnostics, pharmaceutical analysis, and other relevant fields.


Assuntos
Colorimetria , Limite de Detecção , Compostos de Manganês , Nanoestruturas , Óxidos , Oxirredutases , Colorimetria/métodos , Compostos de Manganês/química , Óxidos/química , Nanoestruturas/química , Oxirredutases/metabolismo , Oxirredutases/química , Cinética , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Materiais Biomiméticos/química , Benzidinas/química
6.
Nat Commun ; 15(1): 4858, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871712

RESUMO

Serpentinization, a geochemical process found on modern and ancient Earth, provides an ultra-reducing environment that can support microbial methanogenesis and acetogenesis. Several groups of archaea, such as the order Methanocellales, are characterized by their ability to produce methane. Here, we generate metagenomic sequences from serpentinized springs in The Cedars, California, and construct a circularized metagenome-assembled genome of a Methanocellales archaeon, termed Met12, that lacks essential methanogenesis genes. The genome includes genes for an acetyl-CoA pathway, but lacks genes encoding methanogenesis enzymes such as methyl-coenzyme M reductase, heterodisulfide reductases and hydrogenases. In situ transcriptomic analyses reveal high expression of a multi-heme c-type cytochrome, and heterologous expression of this protein in a model bacterium demonstrates that it is capable of accepting electrons. Our results suggest that Met12, within the order Methanocellales, is not a methanogen but a CO2-reducing, electron-fueled acetogen without electron bifurcation.


Assuntos
Metano , Metano/metabolismo , Genoma Arqueal , Proteínas Arqueais/metabolismo , Proteínas Arqueais/genética , Oxirredutases/genética , Oxirredutases/metabolismo , Metagenoma/genética , Filogenia , Acetilcoenzima A/metabolismo , Dióxido de Carbono/metabolismo , Metagenômica
7.
Proc Natl Acad Sci U S A ; 121(25): e2402384121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38865272

RESUMO

Loss of mitochondrial electron transport complex (ETC) function in the retinal pigment epithelium (RPE) in vivo results in RPE dedifferentiation and progressive photoreceptor degeneration, and has been implicated in the pathogenesis of age-related macular degeneration. Xenogenic expression of alternative oxidases in mammalian cells and tissues mitigates phenotypes arising from some mitochondrial electron transport defects, but can exacerbate others. We expressed an alternative oxidase from Ciona intestinalis (AOX) in ETC-deficient murine RPE in vivo to assess the retinal consequences of stimulating coenzyme Q oxidation and respiration without ATP generation. RPE-restricted expression of AOX in this context is surprisingly beneficial. This focused intervention mitigates RPE mTORC1 activation, dedifferentiation, hypertrophy, stress marker expression, pseudohypoxia, and aerobic glycolysis. These RPE cell autonomous changes are accompanied by increased glucose delivery to photoreceptors with attendant improvements in photoreceptor structure and function. RPE-restricted AOX expression normalizes accumulated levels of succinate and 2-hydroxyglutarate in ETC-deficient RPE, and counteracts deficiencies in numerous neural retinal metabolites. These features can be attributed to the activation of mitochondrial inner membrane flavoproteins such as succinate dehydrogenase and proline dehydrogenase, and alleviation of inhibition of 2-oxyglutarate-dependent dioxygenases such as prolyl hydroxylases and epigenetic modifiers. Our work underscores the importance to outer retinal health of coenzyme Q oxidation in the RPE and identifies a metabolic network critical for photoreceptor survival in the context of RPE mitochondrial dysfunction.


Assuntos
Mitocôndrias , Oxirredutases , Proteínas de Plantas , Epitélio Pigmentado da Retina , Animais , Mitocôndrias/metabolismo , Camundongos , Oxirredutases/metabolismo , Oxirredutases/genética , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Ciona intestinalis/metabolismo , Ubiquinona/metabolismo , Ubiquinona/análogos & derivados , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Degeneração Retiniana/genética , Células Fotorreceptoras de Vertebrados/metabolismo , Células Fotorreceptoras de Vertebrados/patologia
8.
Proc Natl Acad Sci U S A ; 121(25): e2319960121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38865268

RESUMO

Nitrous oxide (N2O), a potent greenhouse gas, can be generated by multiple biological and abiotic processes in diverse contexts. Accurately tracking the dominant sources of N2O has the potential to improve our understanding of N2O fluxes from soils as well as inform the diagnosis of human infections. Isotopic "Site Preference" (SP) values have been used toward this end, as bacterial and fungal nitric oxide reductases (NORs) produce N2O with different isotopic fingerprints, spanning a large range. Here, we show that flavohemoglobin (Fhp), a hitherto biogeochemically neglected yet widely distributed detoxifying bacterial NO reductase, imparts a distinct SP value onto N2O under anoxic conditions (~+10‰) that correlates with typical environmental N2O SP measurements. Using Pseudomonas aeruginosa as a model organism, we generated strains that only contained Fhp or the dissimilatory NOR, finding that in vivo N2O SP values imparted by these enzymes differ by over 10‰. Depending on the cellular physiological state, the ratio of Fhp:NOR varies significantly in wild-type cells and controls the net N2O SP biosignature: When cells grow anaerobically under denitrifying conditions, NOR dominates; when cells experience rapid, increased nitric oxide concentrations under anoxic conditions but are not growing, Fhp dominates. Other bacteria that only make Fhp generate similar N2O SP biosignatures to those measured from our P. aeruginosa Fhp-only strain. Fhp homologs in sequenced bacterial genomes currently exceed NOR homologs by nearly a factor of four. Accordingly, we suggest a different framework to guide the attribution of N2O biological sources in nature and disease.


Assuntos
Óxido Nitroso , Oxirredutases , Pseudomonas aeruginosa , Óxido Nitroso/metabolismo , Oxirredutases/metabolismo , Pseudomonas aeruginosa/metabolismo , Anaerobiose , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Óxido Nítrico/metabolismo
9.
Sci Rep ; 14(1): 13371, 2024 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862560

RESUMO

Broad-spectrum biocatalysts enzymes, Laccases, have been implicated in the complete degradation of harmful pollutants into less-toxic compounds. In this study, two extracellularly produced Laccases were purified to homogeneity from two different Ascomycetes spp. Trichoderma lixii FLU1 (TlFLU1) and Talaromyces pinophilus FLU12 (TpFLU12). The purified enzymes are monomeric units, with a molecular mass of 44 kDa and 68.7 kDa for TlFLU1 and TpFLU12, respectively, on SDS-PAGE and zymogram. It reveals distinct properties beyond classic protein absorption at 270-280 nm, with TlFLU1's peak at 270 nm aligning with this typical range of type II Cu site (white Laccase), while TpFLU12's unique 600 nm peak signifies a type I Cu2+ site (blue Laccase), highlighting the diverse spectral fingerprints within the Laccase family. The Km and kcat values revealed that ABTS is the most suitable substrate as compared to 2,6-dimethoxyphenol, caffeic acid and guaiacol for both Laccases. The bioinformatics analysis revealed critical His, Ile, and Arg residues for copper binding at active sites, deviating from the traditional two His and a Cys motif in some Laccases. The predicted biological functions of the Laccases include oxidation-reduction, lignin metabolism, cellular metal ion homeostasis, phenylpropanoid catabolism, aromatic compound metabolism, cellulose metabolism, and biological adhesion. Additionally, investigation of degradation of polycyclic aromatic hydrocarbons (PAHs) by purified Laccases show significant reductions in residual concentrations of fluoranthene and anthracene after a 96-h incubation period. TlFLU1 Laccase achieved 39.0% and 44.9% transformation of fluoranthene and anthracene, respectively, while TpFLU12 Laccase achieved 47.2% and 50.0% transformation, respectively. The enzyme structure-function relationship study provided insights into the catalytic mechanism of these Laccases for possible biotechnological and industrial applications.


Assuntos
Lacase , Talaromyces , Trichoderma , Talaromyces/enzimologia , Lacase/metabolismo , Lacase/química , Lacase/isolamento & purificação , Lacase/genética , Trichoderma/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/genética , Especificidade por Substrato , Cobre/metabolismo , Cinética , Oxirredutases/metabolismo , Oxirredutases/química , Oxirredutases/isolamento & purificação , Domínio Catalítico
10.
J Obes ; 2024: 7204607, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38831961

RESUMO

Obesity is a complex chronic disease characterized by excess body fat (adipose) that is harmful to health and has been a major global health problem. It may be associated with several diseases, such as nonalcoholic fatty liver disease (NAFLD). Polyunsaturated fatty acids (PUFA) are lipid mediators that have anti-inflammatory characteristics and can be found in animals and plants, with capybara oil (CO) being a promising source. So, we intend to evaluate the hepatic pathophysiological alterations in C57Bl/6 mice with NAFLD, caused by obesity, and the possible beneficial effects of OC in the treatment of this disease. Eighteen 3-month-old male C57Bl/6 mice received a control or high-fat diet for 18 weeks. From the 15th to the 18th week, the animals received treatment-through orogastric gavage-with placebo or free capybara oil (5 g/kg). Parameters inherent to body mass, glucose tolerance, evaluation of liver enzymes, percentage of hepatic steatosis, oxidative stress, the process of cell death with the apoptotic biomarkers (Bax, Bcl2, and Cytochrome C), and the ultrastructure of hepatocytes were analyzed. Even though the treatment with CO was not able to disassemble the effects on the physiological parameters, it proved to be beneficial in reversing the morphological and ultrastructural damage present in the hepatocytes. Thus, demonstrating that CO has beneficial effects in reducing steatosis and the apoptotic pathway, it is a promising treatment for NAFLD.


Assuntos
Apoptose , Fígado , Hepatopatia Gordurosa não Alcoólica , Óleos , Roedores , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/terapia , Masculino , Animais , Camundongos , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Hepatócitos/ultraestrutura , Óleos/farmacologia , Óleos/uso terapêutico , Obesidade/complicações , Apoptose/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/ultraestrutura , Oxirredutases/metabolismo , Ativação Enzimática/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
11.
Environ Microbiol Rep ; 16(3): e13277, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38881156

RESUMO

We describe the genome of an Eremiobacterota population from tundra soil that contains the minimal set of nif genes needed to fix atmospheric N2. This putative diazotroph population, which we name Candidatus Lamibacter sapmiensis, links for the first time Eremiobacterota and N2 fixation. The integrity of the genome and its nif genes are well supported by both environmental and taxonomic signals. Ca. Lamibacter sapmiensis contains three nifH homologues and the complementary set of nifDKENB genes that are needed to assemble a functional nitrogenase. The putative diazotrophic role of Ca. Lamibacter sapmiensis is supported by the presence of genes that regulate N2 fixation and other genes involved in downstream processes such as ammonia assimilation. Similar to other Eremiobacterota, Ca. Lamibacter sapmiensis encodes the potential for atmospheric chemosynthesis via CO2 fixation coupled with H2 and CO oxidation. Interestingly, the presence of a N2O reductase indicates that this population could play a role as a N2O sink in tundra soils. Due to the lack of activity data, it remains uncertain if Ca. Lamibacter sapmiensis is able to assemble a functional nitrogenase and participate in N2 fixation. Confirmation of this ability would be a testament to the great metabolic versatility of Eremiobacterota, which appears to underlie their ecological success in cold and oligotrophic environments.


Assuntos
Fixação de Nitrogênio , Microbiologia do Solo , Tundra , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Filogenia , Nitrogenase/metabolismo , Nitrogenase/genética , Oxirredutases/genética , Oxirredutases/metabolismo , Genoma Bacteriano/genética
12.
J Agric Food Chem ; 72(22): 12685-12695, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38771136

RESUMO

Halogenation plays a unique role in the design of agrochemicals. Enzymatic halogenation reactions have attracted great attention due to their excellent specificity and mild reaction conditions. S-adenosyl-l-methionine (SAM)-dependent halogenases mediate the nucleophilic attack of halide ions (X-) to SAM to produce 5'-XDA. However, only 11 SAM-dependent fluorinases and 3 chlorinases have been reported, highlighting the desire for additional halogenases. SAM-dependent hydroxide adenosyltransferase (HATase) has a similar reaction mechanism as halogenases but uses water as a substrate instead of halide ions. Here, we explored a HATase from the thermophile Thermotoga maritima MSB8 and transformed it into a halogenase. We identified a key dyad W8L/V71T for the halogenation reaction. We also obtained the best performing mutants for each halogenation reaction: M1, M2 and M4 for Cl-, Br- and I-, respectively. The M4 mutant retained the thermostability of HATase in the iodination reaction at 80 °C, which surpasses the natural halogenase SalL. QM/MM revealed that these mutants bind halide ions with more suitable angles for nucleophilic attack of C5' of SAM, thus conferring halogenation capabilities. Our work achieved the halide ion specificity of halogenases and generated thermostable halogenases for the first time, which provides new opportunities to expand the halogenase repertoire from hydroxylase.


Assuntos
Proteínas de Bactérias , Thermotoga maritima , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Thermotoga maritima/enzimologia , Thermotoga maritima/genética , Thermotoga maritima/química , Halogenação , Especificidade por Substrato , S-Adenosilmetionina/metabolismo , S-Adenosilmetionina/química , Oxirredutases/química , Oxirredutases/metabolismo , Oxirredutases/genética , Biocatálise
13.
J Agric Food Chem ; 72(22): 12425-12433, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38781442

RESUMO

Phytoene desaturase (PDS) is a critical functional enzyme in blocking ζ-carotene biosynthesis and is one of the bleaching herbicide targets. At present, norflurazon (NRF) is the only commercial pyridazine herbicide targeting PDS. Therefore, developing new and diverse pyridazine herbicides targeting PDS is urgently required. In this study, diflufenican (BF) was used as the lead compound, and a scaffold-hopping strategy was employed to design and synthesize some pyridazine derivatives based on the action mode of BF and PDS. The preemergence herbicidal activity tests revealed that compound 6-chloro-N-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenoxy)pyridazine-4-carboxamide (B1) with 2,4-diF substitution in the benzeneamino ring showed 100% inhibition rates against the roots and stems of Echinochloa crus-galli and Portulaca oleracea at 100 µg/mL, superior to the inhibition rates of BF. Meanwhile, compound B1 demonstrated excellent postemergence herbicidal activity against broadleaf weeds, which was similar to that of BF (inhibition rate of 100%) but superior to that of NRF. This indicated that 6-Cl in the pyridazine ring is the key group for postemergence herbicidal activity. In addition, compound B1 could induce downregulation of PDS gene expression, 15-cis-phytoene accumulation, and Y(II) deficiency and prevent photosynthesis. Therefore, B1 can be considered as a promising candidate for developing high-efficiency PDS inhibitors.


Assuntos
Echinochloa , Herbicidas , Oxirredutases , Proteínas de Plantas , Plantas Daninhas , Piridazinas , Herbicidas/farmacologia , Herbicidas/química , Piridazinas/farmacologia , Piridazinas/química , Echinochloa/efeitos dos fármacos , Echinochloa/enzimologia , Echinochloa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/antagonistas & inibidores , Oxirredutases/genética , Oxirredutases/metabolismo , Oxirredutases/antagonistas & inibidores , Oxirredutases/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Plantas Daninhas/genética , Relação Estrutura-Atividade , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Estrutura Molecular
14.
J Agric Food Chem ; 72(22): 12832-12841, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38785419

RESUMO

Capsaicin (CAP) is a primary indicator for assessing the level of pungency. Herein, iron-based single-atom nanozymes (SAzymes) (Fe/NC) with exceptional oxidase-like activity were used to construct an immunosensor for CAP analysis. Fe/NC could imitate oxidase actions by transforming O2 to •O2- radicals in the absence of hydrogen peroxide (H2O2), which could avoid complex operations and unstable results. By regulating the Fe atom loads, an optimal Fe0.7/NC atom usage rate could improve the catalytic activity (Michaelis-Menten constant (Km) = 0.09 mM). Fe0.7/NC was integrated with goat antimouse IgG by facile mix incubation to develop a competitive enzyme-linked immunosorbent assay (ELISA). Our Fe0.7/NC immunosensing platform is anticipated to outperform the conventional ELISA in terms of stability and shelf life. The proposed immunosensor provided color responses across 0.01-1000 ng/mL CAP concentrations, with a detection limit of 0.046 ng/mL. Fe/NC may have potential as nanozymes for CAP detection in spicy foods, with promising applications in food biosensing.


Assuntos
Técnicas Biossensoriais , Capsaicina , Capsaicina/análise , Capsaicina/química , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Oxirredutases/química , Ensaio de Imunoadsorção Enzimática/métodos , Ferro/química , Ferro/análise , Limite de Detecção , Peróxido de Hidrogênio/química , Análise de Alimentos/métodos
15.
Mikrochim Acta ; 191(6): 352, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806756

RESUMO

Developing convenient and reliable methods for Hg2+ monitoring is highly important. Some precious metal nanomaterials with intriguing peroxidase-like activity have been used for highly sensitive Hg2+ detection. However, H2O2 must be added during these detections, which impedes practical applications of Hg2+ sensors due to its susceptible decomposition by environmental factors. Herein, we discovered that the combination of Hg2+ and palladium metal-organic framework@graphene (Pd-MOF@GNs) exhibits oxidase-like activity (OXD). In the absence of H2O2, this activity not only catalyzes the oxidation of chromogenic substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) or o-phenylenediamine (OPD) to produce a color change but also enhances the electrical signals during OPD oxidation. Based on these properties, an effective and convenient dual-mode colorimetric and electrochemical sensor for Hg2+ has been developed. The colorimetric and amperometric linear relationships for Hg2+ were 0.045 µM-0.25 mM and 0.020 µM-2.0 mM, respectively. The proposed strategy shows good recovery in real sample tests, indicating promising prospects for multiple environmental sample detection of Hg2+ without relying on H2O2. The colorimetric and electrochemical dual-mode Hg2+ sensor is expected to hold great potentials in applications such as environmental monitoring, rapid field detection, and integration into smartphone detection of Hg2+.


Assuntos
Colorimetria , Técnicas Eletroquímicas , Grafite , Limite de Detecção , Mercúrio , Estruturas Metalorgânicas , Paládio , Grafite/química , Colorimetria/métodos , Mercúrio/análise , Mercúrio/química , Estruturas Metalorgânicas/química , Paládio/química , Técnicas Eletroquímicas/métodos , Benzidinas/química , Oxirredução , Poluentes Químicos da Água/análise , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise , Oxirredutases/química , Oxirredutases/metabolismo , Fenilenodiaminas/química
16.
Appl Microbiol Biotechnol ; 108(1): 323, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713233

RESUMO

Ergot alkaloids (EAs) are a diverse group of indole alkaloids known for their complex structures, significant pharmacological effects, and toxicity to plants. The biosynthesis of these compounds begins with chanoclavine-I aldehyde (CC aldehyde, 2), an important intermediate produced by the enzyme EasDaf or its counterpart FgaDH from chanoclavine-I (CC, 1). However, how CC aldehyde 2 is converted to chanoclavine-I acid (CC acid, 3), first isolated from Ipomoea violacea several decades ago, is still unclear. In this study, we provide in vitro biochemical evidence showing that EasDaf not only converts CC 1 to CC aldehyde 2 but also directly transforms CC 1 into CC acid 3 through two sequential oxidations. Molecular docking and site-directed mutagenesis experiments confirmed the crucial role of two amino acids, Y166 and S153, within the active site, which suggests that Y166 acts as a general base for hydride transfer, while S153 facilitates proton transfer, thereby increasing the acidity of the reaction. KEY POINTS: • EAs possess complicated skeletons and are widely used in several clinical diseases • EasDaf belongs to the short-chain dehydrogenases/reductases (SDRs) and converted CC or CC aldehyde to CC acid • The catalytic mechanism of EasDaf for dehydrogenation was analyzed by molecular docking and site mutations.


Assuntos
Aldeídos , Alcaloides de Claviceps , Aldeídos/metabolismo , Aldeídos/química , Domínio Catalítico , Alcaloides de Claviceps/biossíntese , Alcaloides de Claviceps/química , Alcaloides de Claviceps/metabolismo , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Oxirredução , Oxirredutases/metabolismo , Oxirredutases/genética , Oxirredutases/química
17.
Org Lett ; 26(21): 4463-4468, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38747552

RESUMO

(S)-1-(4-Methoxybenzyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline ((S)-1-(4-methoxybenzyl)-OHIQ) is the key intermediate of the nonopioid antitussive dextromethorphan. In this study, (S)-IR61-V69Y/P123A/W179G/F182I/L212V (M4) was identified with a 766-fold improvement in catalytic efficiency compared with wide-type IR61 through enzyme engineering. M4 could completely convert 200 mM of 1-(4-methoxybenzyl)-3,4,5,6,7,8-hexahydroisoquinoline into (S)-1-(4-methoxybenzyl)-OHIQ in 77% isolated yield, with >99% enantiomeric excess and a high space-time yield of 542 g L-1 day-1, demonstrating a great potential for the synthesis of dextromethorphan intermediate in industrial applications.


Assuntos
Dextrometorfano , Dextrometorfano/química , Dextrometorfano/síntese química , Estrutura Molecular , Oxirredutases/metabolismo , Oxirredutases/química , Iminas/química , Estereoisomerismo , Antitussígenos/química , Antitussígenos/síntese química , Engenharia de Proteínas
18.
J Phys Chem Lett ; 15(22): 5804-5813, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38781458

RESUMO

Nanozymes are unique materials with many valuable properties for applications in biomedicine, biosensing, environmental monitoring, and beyond. In this work, we developed a machine learning (ML) approach to search for new nanozymes and deployed a web platform, DiZyme, featuring a state-of-the-art database of nanozymes containing 1210 experimental samples, catalytic activity prediction, and DiZyme Assistant interface powered by a large language model (LLM). For the first time, we enable the prediction of multiple catalytic activities of nanozymes by training an ensemble learning algorithm achieving R2 = 0.75 for the Michaelis-Menten constant and R2 = 0.77 for the maximum velocity on unseen test data. We envision an accurate prediction of multiple catalytic activities (peroxidase, oxidase, and catalase) promoting novel applications for a wide range of surface-modified inorganic nanozymes. The DiZyme Assistant based on the ChatGPT model provides users with supporting information on experimental samples, such as synthesis procedures, measurement protocols, etc. DiZyme (dizyme.aicidlab.itmo.ru) is now openly available worldwide.


Assuntos
Aprendizado de Máquina , Catálise , Catalase/química , Catalase/metabolismo , Nanoestruturas/química , Oxirredutases/química , Oxirredutases/metabolismo , Peroxidase/química , Peroxidase/metabolismo , Algoritmos
19.
Anal Methods ; 16(22): 3577-3586, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38787692

RESUMO

Analysis of exosomes provides important information for rapid and non-invasive screening of tumors. However, sensitive and convenient detection of exosomes remains technically challenging to date. Herein, a colorimetric aptasensor based on the light-stimulated oxidase-mimicking activity of FITC was constructed for detecting ovarian cancer (OC) exosomes. The aptasensor contained an EpCAM aptamer to capture OC exosomes. Cholesterol and fluorescein (FITC) were used to modify either end of the DNA (DNA anchor). The DNA anchor could combine with exosomes through a hydrophobic reaction between cholesterol and the lipid membrane. FITC oxidized 3,3',5,5'-tetramethylbenzidine (TMB) under a 365 nm LED light source in a temporally controllable manner under mild conditions, causing the solution to change from colorless to blue, and the corresponding UV-vis absorbance increased. Based on this principle, the exosomes were qualitatively analyzed by observing the color change with the naked eye. In parallel, the exosome concentration was also detected using UV-vis spectrophotometry. The linear range was from 2 × 105 to 100 × 105 particles per mL with a limit of detection of 1.77 × 105 particles per mL. The developed aptasensor also exhibited favorable selectivity and could discriminate the exosomes from OC cells and normal cells. Besides, the receiver operating characteristic (ROC) curve demonstrates that it is possible to distinguish between patients with OC and healthy donors (HDs) using exosomes as the biomarker. Our technology may expand the applications of DNA-based detection method-enabled OC diagnostic tools.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Colorimetria , Exossomos , Exossomos/química , Exossomos/metabolismo , Humanos , Colorimetria/métodos , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Feminino , Neoplasias Ovarianas , Oxirredutases/química , Oxirredutases/metabolismo , Luz , Limite de Detecção , Fluoresceína/química , Benzidinas/química , Linhagem Celular Tumoral
20.
Microbes Environ ; 39(5)2024.
Artigo em Inglês | MEDLINE | ID: mdl-38811235

RESUMO

The extremely halophilic archaeon Haloarcula japonica accumulates the C50 carotenoid, bacterioruberin (BR). To reveal the BR biosynthetic pathway, unidentified phytoene desaturase candidates were functionally characterized in the present study. Two genes encoding the potential phytoene desaturases, c0507 and d1086, were found from the Ha. japonica genome sequence by a homology search using the Basic Local Align Search Tool. Disruption mutants of c0507 and d1086 and their complemented strains transformed with expression plasmids for c0507 and d1086 were subsequently constructed. High-performance liquid chromatography (HPLC) ana-lyses of carotenoids produced by these strains revealed that C0507 and D1086 were both bifunctional enzymes with the same activities as both phytoene desaturase (CrtI) and 3,4-desaturase (CrtD). C0507 and D1086 complemented each other during BR biosynthesis in Ha. japonica. This is the first study to identify two distinct enzymes with both CrtI and CrtD activities in an extremely halophilic archaeon.


Assuntos
Carotenoides , Haloarcula , Oxirredutases , Carotenoides/metabolismo , Haloarcula/genética , Haloarcula/enzimologia , Haloarcula/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Vias Biossintéticas/genética , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Teste de Complementação Genética , Filogenia
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