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1.
Sheng Wu Gong Cheng Xue Bao ; 37(8): 2870-2877, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472304

RESUMO

Asthma is a common respiratory disease that affects 300 million of people worldwide, posing a serious health risk and medical burden. Development of new anti-asthmatic drugs and alternative treatment regimens is therefore encouraged. Recent studies have shown that Epidermal Growth Factor Receptor (EGFR) is involved in asthma development. In order to construct nanoparticles targeting EGFR for asthma treatment, a single chain antibody fragment (scFv) against EGFR was genetically engineered and modified at the N-terminal end of the human ferritin H-chain (FTH1) to construct Anti EGFR scFv::FTH1/FTH1 nanoparticles. Transmission electron microscopy showed that the nanoparticles were self-assembled into hollow cage-like structures with the particle size of about 12 nm. Semi-quantitative analysis of the purified nanoparticles by SDS-PAGE revealed the mass ratio of FTH1 to Anti EGFR scFv::FTH1 was 7:3. In House Dust Mite (HDM) driven models, Anti EGFR scFv::FTH1/FTH1 nanoparticles efficiently attenuated several key features of asthma, including goblet cell hyperplasia, mucous metaplasia and subepithelial fibrosis, showing the potential of using ferritin based nanoparticle for asthma treatment.


Assuntos
Asma , Nanopartículas , Anticorpos de Cadeia Única , Asma/tratamento farmacológico , Ferritinas , Humanos , Oxirredutases , Anticorpos de Cadeia Única/genética
2.
Enzyme Microb Technol ; 150: 109880, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489033

RESUMO

The ene reductases (ERs) from the old yellow enzymes (OYEs) family have the ability to reduce activated alkenes to generate up to two stereocenters, therefore they have been received extensive attention as powerful biocatalysts. In this study, through gene mining, four ERs were identified from the genomes of Ensifer adhaerens, Pseudomonas fluorescens, and Pseudomonas veronil. The biocatalytic properties of these four ERs were identified, and their applications in the synthesis process of dihydrocarvone and profen derivatives were further evaluated. Among them, three ERs (EaER2, PvER1, and PvER2) belonging to the classic OYEs showed the best catalytic activity at 30 °C and pH 7.0 (100 mM potassium phosphate buffer) and the PfER2, which belongs to the thermophilic-like OYEs exhibited the best catalytic at 40 °C and pH 7.0 (100 mM potassium phosphate buffer). When exploring the influence of organic solvents on the catalytic efficiency, it was found that the four ERs were more sensitive to toluene and had tolerance to several other selected organic solvents. In addition, EaER2, PfER2, PvER1 and PvER2 showed excellent catalytic activity toward carvone, and the stereoselectivity of PvER2 toward carvone could reach up to 88.7 % de. EaER2 and PfER2 can catalyze the synthesis of a variety of profen derivatives with a stereoselectivity over 99 % ee. Moreover, through homology modeling and molecular docking, we preliminarily explained the mechanism of catalytic activity and stereoselectivity of the four ERs, which provided a solid base on the rational design of their stereo-preference in the future. The discovery of EaER2, PfER2, PvER1, and PvER2 provides four new enzyme sources for the study of the OYEs family and enriches the biocatalytic toolbox of ERs. Our exploration of the enzymatic properties of these four ERs will provide the sufficient data basis for future research and industrialization progress.


Assuntos
Oxirredutases , Biocatálise , Monoterpenos Cicloexânicos , Simulação de Acoplamento Molecular , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Rhizobiaceae
3.
Enzyme Microb Technol ; 150: 109884, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489037

RESUMO

Tyrosinase plays an essential role in melanin biosynthesis and inherently exhibits both monophenolase and diphenolase activity. A first derivative synchronous fluorometric assay was established for directly monitoring monophenolase activity. The zero-crossing point at 322 nm for the first-derivative under synchronous fluorescence with Δλ = 67 nm was utilized to selectively quantify tyrosine in the presence of the reaction product dihydroxyphenylalanine (DOPA). The limit of detection (LOD) for tyrosine was 0.54 µM. The fluorescence intensity of tyrosine was monitored at intervals of 30 s to establish the time course of tyrosine consumption. The LOD for the monophenolase activity was 0.0706 U⋅ mL-1. The Michaelis-Menten e constant and maximum speed were 21.83 µM and 1.12 µM min-1, respectively. Zinc ions competitively inhibited the monophenolase activity, with an IC50 value of 14.36 µM. This assay is easily and rapidly executed and is of great significance for analyzing the kinetics of enzymatic reactions and in fundamental research on monophenolase. This approach has potential applications in the discovery of tyrosinase inhibitors for medicine and cosmetics, as well as in the industrial synthesis of substituted o-diphenol intermediates.


Assuntos
Monofenol Mono-Oxigenase , Oxirredutases , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Oxirredutases/metabolismo , Tirosina/metabolismo
4.
Biomed Environ Sci ; 34(8): 616-622, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34474721

RESUMO

Objective: To evaluate multidrug resistant loop-mediated isothermal amplification (MDR-LAMP) assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the rpoB, katG, and inhA genes at the Chinese Center for Disease Control and Prevention. Methods: MDR-LAMP assay was evaluated using 100 Mycobacterium tuberculosis ( Mtb) isolates obtained from the National Reference Laboratory for Tuberculosis in China. Phenotypic resistance to isoniazid and rifampicin and whole-genome sequencing served as reference standards. Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDR-LAMP were 85.5%, 93.6%, 96.7%, and 74.4% for the detection of resistance to isoniazid and rifampicin, respectively, and 80.5%, 92.3%, 98.6%, and 41.4% for the detection of Mtb cultured from smear-positive sputum samples, respectively. When DNA sequencing was used as the reference standard, the sensitivity, specificity, PPV, and NPV of MDR-LAMP were 93.1%, 92.3%, 97.2%, and 82.8% for the detection of katG and inhA gene mutations, respectively, and 89.1%, 88.9%, 93.4%, and 81.1% for the detection of rpoB gene mutation, respectively. Conclusion: MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of Mtb isolates.


Assuntos
DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla/genética , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Antituberculosos , Proteínas de Bactérias/genética , Catalase/genética , RNA Polimerases Dirigidas por DNA/genética , Isoniazida , Mutação , Mycobacterium tuberculosis/isolamento & purificação , Oxirredutases/genética , Fenótipo , Rifampina , Sequenciamento Completo do Genoma
5.
Nat Commun ; 12(1): 5236, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475399

RESUMO

New drugs are urgently needed to combat the global TB epidemic. Targeting simultaneously multiple respiratory enzyme complexes of Mycobacterium tuberculosis is regarded as one of the most effective treatment options to shorten drug administration regimes, and reduce the opportunity for the emergence of drug resistance. During infection and proliferation, the cytochrome bd oxidase plays a crucial role for mycobacterial pathophysiology by maintaining aerobic respiration at limited oxygen concentrations. Here, we present the cryo-EM structure of the cytochrome bd oxidase from M. tuberculosis at 2.5 Å. In conjunction with atomistic molecular dynamics (MD) simulation studies we discovered a previously unknown MK-9-binding site, as well as a unique disulfide bond within the Q-loop domain that defines an inactive conformation of the canonical quinol oxidation site in Actinobacteria. Our detailed insights into the long-sought atomic framework of the cytochrome bd oxidase from M. tuberculosis will form the basis for the design of highly specific drugs to act on this enzyme.


Assuntos
Grupo dos Citocromos b/química , Grupo dos Citocromos d/química , Complexo de Proteínas da Cadeia de Transporte de Elétrons/química , Mycobacterium tuberculosis/enzimologia , Proteínas de Bactérias/química , Sítios de Ligação , Microscopia Crioeletrônica , Simulação de Dinâmica Molecular , Oxirredutases/química , Conformação Proteica , Subunidades Proteicas , Vitamina K 2/análogos & derivados , Vitamina K 2/química
7.
Nat Commun ; 12(1): 5493, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34535675

RESUMO

Macromolecular dynamics manifest as disorder in structure determination, which is subsequently accounted for by displacement parameters (also called temperature factors, or B-factors) or alternate conformations. Though B-factors contain detailed information about structural dynamics, they are the total of multiple sources of disorder, making them difficult to interpret and thus little-used in structural analysis. We report here an analytical approach for decomposing molecular disorder into a parsimonious hierarchical series of contributions, providing an intuitive basis for quantitative structural-dynamics analysis. We demonstrate the decomposition of disorder on example SARS-CoV-2 and STEAP4 structures, from both crystallographic and cryo-electron microscopy data, and reveal how understanding of the macromolecular disorder leads to deeper understanding of molecular motions and flexibility, and suggests hypotheses for molecular mechanisms.


Assuntos
Proteases 3C de Coronavírus/química , Substâncias Macromoleculares/química , Simulação de Dinâmica Molecular , SARS-CoV-2/enzimologia , COVID-19 , Microscopia Crioeletrônica , Humanos , Proteínas de Membrana/química , Oxirredutases/química , Conformação Proteica
8.
Free Radic Biol Med ; 175: 206-215, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34506903

RESUMO

Flavonoids are natural polyphenolic compounds with a diverse array of biological activities and health-promoting effects. Recent studies have found that 4,4'-dimethoxychalcone (DMC) promoted longevity via autophagy; however, its targets are currently unknown. Herein, we employed an unbiased thermal proteome profiling (TPP) method and identified multiple targets of DMC, including ALDH1A3, ALDH2, and PTGES2. We further determined the dissociation constant (Kd) of DMC and ALDH1A3 to be 2.8 µM using microscale thermophoresis (MST) analysis, which indicated that DMC inhibited ALDH1A3 activity and aggravated cellular oxidative stress. DMC treatment significantly increased cellular reactive oxygen species (ROS) production and inhibited cancer cell growth. Quantitative proteomic analysis showed that DMC upregulated proteins associated with stress-responses and downregulated proteins associated with cell cycle progression, and this was confirmed using cell cycle analysis. Taken together, we showed that TPP is an effective tool with which to identify flavonoid targets and set a precedent for deciphering flavonoid function in the future. We have demonstrated that DMC inhibited cell proliferation via ROS-induced cell cycle arrest and is an anti-proliferative agent in cancer treatment.


Assuntos
Flavonoides , Proteômica , Apoptose , Proliferação de Células , Flavonoides/farmacologia , Estresse Oxidativo , Oxirredutases , Espécies Reativas de Oxigênio
9.
BMJ Case Rep ; 14(9)2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34544705

RESUMO

Immune-mediated necrotising myopathy is a subtype of idiopathic inflammatory myopathy characterised by muscle fibre necrosis without significant inflammatory infiltrate. Anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) myopathy is seen in 6%-10% of idiopathic inflammatory myopathy and is diagnosed in the context of elevated serum creatine kinase levels, proximal muscle weakness and anti-HMGCR autoantibodies. We recently encountered a 61-year-old man with anti-HMGCR myopathy with an atypical skin manifestation, partially responsive to triple therapy with steroids, intravenous immunoglobulin (IVIG) and rituximab. To our knowledge, there have been only four reported cases of skin rash associated with anti-HMGCR myopathy. Our case demonstrates the importance of recognising atypical manifestations of anti-HMGCR myopathy. Early addition of IVIG and rituximab is also critical in patients not responding to steroid monotherapy. Delay in achieving remission leads to prolonged steroid use, lower likelihood of beginning physical therapy and overall worse clinical outcomes.


Assuntos
Doenças Musculares , Miosite , Coenzimas , Humanos , Hidroximetilglutaril-CoA Redutases , Masculino , Pessoa de Meia-Idade , Doenças Musculares/induzido quimicamente , Doenças Musculares/diagnóstico , Doenças Musculares/tratamento farmacológico , Miosite/induzido quimicamente , Miosite/diagnóstico , Miosite/tratamento farmacológico , Oxirredutases
10.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361015

RESUMO

The sacred lotus (Nelumbo nucifera) can maintain a stable floral chamber temperature between 30 and 35 °C when blooming despite fluctuations in ambient temperatures between about 8 and 45 °C, but the regulatory mechanism of floral thermogenesis remains unclear. Here, we obtained comprehensive protein profiles from receptacle tissue at five developmental stages using data-independent acquisition (DIA)-based quantitative proteomics technology to reveal the molecular basis of floral thermogenesis of N. nucifera. A total of 6913 proteins were identified and quantified, of which 3513 differentially abundant proteins (DAPs) were screened. Among them, 640 highly abundant proteins during the thermogenic stages were mainly involved in carbon metabolism processes such as the tricarboxylic acid (TCA) cycle. Citrate synthase was identified as the most connected protein in the protein-protein interaction (PPI) network. Next, the content of alternative oxidase (AOX) and plant uncoupling protein (pUCP) in different tissues indicated that AOX was specifically abundant in the receptacles. Subsequently, a protein module highly related to the thermogenic phenotype was identified by the weighted gene co-expression network analysis (WGCNA). In summary, the regulation mechanism of floral thermogenesis in N. nucifera involves complex regulatory networks, including TCA cycle metabolism, starch and sucrose metabolism, fatty acid degradation, and ubiquinone synthesis, etc.


Assuntos
Adaptação Fisiológica , Flores/metabolismo , Redes Reguladoras de Genes , Nelumbo/genética , Mapas de Interação de Proteínas , Proteoma/metabolismo , Citrato (si)-Sintase/genética , Citrato (si)-Sintase/metabolismo , Ciclo do Ácido Cítrico , Flores/genética , Regulação da Expressão Gênica de Plantas , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Nelumbo/crescimento & desenvolvimento , Nelumbo/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteoma/genética , Temperatura
11.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360597

RESUMO

Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis and infects almost one-third of the global human population. A lack of effective drugs and vaccines and the emergence of drug resistant parasites highlight the need for the development of new drugs. The mitochondrial electron transport chain (ETC) is an essential pathway for energy metabolism and the survival of T. gondii. In apicomplexan parasites, malate:quinone oxidoreductase (MQO) is a monotopic membrane protein belonging to the ETC and a key member of the tricarboxylic acid cycle, and has recently been suggested to play a role in the fumarate cycle, which is required for the cytosolic purine salvage pathway. In T. gondii, a putative MQO (TgMQO) is expressed in tachyzoite and bradyzoite stages and is considered to be a potential drug target since its orthologue is not conserved in mammalian hosts. As a first step towards the evaluation of TgMQO as a drug target candidate, in this study, we developed a new expression system for TgMQO in FN102(DE3)TAO, a strain deficient in respiratory cytochromes and dependent on an alternative oxidase. This system allowed, for the first time, the expression and purification of a mitochondrial MQO family enzyme, which was used for steady-state kinetics and substrate specificity analyses. Ferulenol, the only known MQO inhibitor, also inhibited TgMQO at IC50 of 0.822 µM, and displayed different inhibition kinetics compared to Plasmodium falciparum MQO. Furthermore, our analysis indicated the presence of a third binding site for ferulenol that is distinct from the ubiquinone and malate sites.


Assuntos
Cumarínicos/metabolismo , Malatos/metabolismo , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Proteínas de Protozoários/metabolismo , Toxoplasma/enzimologia , Ubiquinona/metabolismo , Animais , Humanos , Proteínas Mitocondriais/genética , Oxirredutases/genética , Proteínas de Protozoários/genética , Especificidade por Substrato
12.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445601

RESUMO

Ferroptosis, an iron-dependent form of programmed cell death, has excellent potential as an anti-cancer therapeutic strategy in different types of tumors, especially in RAS-mutated ones. However, the function of ferroptosis for inhibiting neuroblastoma, a common child malignant tumor with minimal treatment, is unclear. This study investigated the anti-cancer function of ferroptosis inducer Erastin or RSL3 in neuroblastoma N2A cells. Our results show that Erastin or RSL3 induces ROS level and cell death and, therefore, reduces the viability of RAS-proficient N2A cells. Importantly, inhibitors to ferroptosis, but not apoptosis, ameliorate the high ROS level and viability defect in Erastin- or RSL3-treated cells. In addition, our data also show that N2A cells are much more sensitive to ferroptosis inducers than primary mouse cortical neural stem cells (NSCs) or neurons. Moreover, a higher level of ROS and PARylation is evidenced in N2A, but not NSCs. Mechanically, ferritin heavy chain 1 (Fth), the ferroxidase function to oxidate redox-active Fe2+ to redox-inactive Fe3+, is likely responsible for the hypersensitivity of N2A to ferroptosis induction since its expression is lower in N2A compared to NSCs; ectopic expression of Fth reduces ROS levels and cell death, and induces expression of GPX4 and cell viability in N2A cells. Most importantly, neuroblastoma cell lines express a significantly low level of Fth than almost all other types of cancer cell lines. All these data suggest that Erastin or RSL3 induce ferroptosis cell death in neuroblastoma N2A cells, but not normal neural cells, regardless of RAS mutations, due to inadequate FTH. This study, therefore, provides new evidence that ferroptosis could be a promising therapeutic target for neuroblastoma.


Assuntos
Ferritinas/metabolismo , Ferroptose , Células-Tronco Neurais/patologia , Neuroblastoma/patologia , Oxirredutases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas ras/metabolismo , Animais , Apoptose , Feminino , Ferritinas/genética , Ferro/metabolismo , Peroxidação de Lipídeos , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Neuroblastoma/genética , Neuroblastoma/metabolismo , Oxirredução , Oxirredutases/genética , Piperazinas/metabolismo , Proteínas ras/genética
13.
Int J Mol Sci ; 22(16)2021 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-34445240

RESUMO

Nitroaromatic compounds (ArNO2) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO2 and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO2, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO2 by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.


Assuntos
Bactérias/enzimologia , Proteínas de Bactérias , Citotoxinas , Elétrons , Flavoproteínas , Nitrocompostos , Oxirredutases , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Citotoxinas/química , Citotoxinas/farmacologia , Flavoproteínas/química , Flavoproteínas/metabolismo , Humanos , Nitrocompostos/química , Nitrocompostos/farmacologia , Oxirredução , Oxirredutases/química , Oxirredutases/metabolismo
14.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445672

RESUMO

In mammalian cells, two cellular organelles, mitochondria and peroxisomes, share the ability to degrade fatty acid chains. Although each organelle harbors its own fatty acid ß-oxidation pathway, a distinct mitochondrial system feeds the oxidative phosphorylation pathway for ATP synthesis. At the same time, the peroxisomal ß-oxidation pathway participates in cellular thermogenesis. A scientific milestone in 1965 helped discover the hepatomegaly effect in rat liver by clofibrate, subsequently identified as a peroxisome proliferator in rodents and an activator of the peroxisomal fatty acid ß-oxidation pathway. These peroxisome proliferators were later identified as activating ligands of Peroxisome Proliferator-Activated Receptor α (PPARα), cloned in 1990. The ligand-activated heterodimer PPARα/RXRα recognizes a DNA sequence, called PPRE (Peroxisome Proliferator Response Element), corresponding to two half-consensus hexanucleotide motifs, AGGTCA, separated by one nucleotide. Accordingly, the assembled complex containing PPRE/PPARα/RXRα/ligands/Coregulators controls the expression of the genes involved in liver peroxisomal fatty acid ß-oxidation. This review mobilizes a considerable number of findings that discuss miscellaneous axes, covering the detailed expression pattern of PPARα in species and tissues, the lessons from several PPARα KO mouse models and the modulation of PPARα function by dietary micronutrients.


Assuntos
Ácidos Graxos/metabolismo , PPAR alfa/metabolismo , Peroxissomos/metabolismo , Acil-CoA Oxidase/metabolismo , Animais , Humanos , Fígado/metabolismo , Oxirredução , Oxirredutases/metabolismo , PPAR alfa/fisiologia , Proliferadores de Peroxissomos , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores do Ácido Retinoico/metabolismo , Elementos de Resposta/genética , Receptores X de Retinoides/metabolismo , Ativação Transcricional/genética
15.
Int J Mol Sci ; 22(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34445771

RESUMO

The dehydrogenase pathway and the succinylase pathway are involved in the synthesis of L-lysine in Corynebacterium glutamicum. Despite the low contribution rate to L-lysine production, the dehydrogenase pathway is favorable for its simple steps and potential to increase the production of L-lysine. The effect of ammonium (NH4+) concentration on L-lysine biosynthesis was investigated, and the results indicated that the biosynthesis of L-lysine can be promoted in a high NH4+ environment. In order to reduce the requirement of NH4+, the nitrogen source regulatory protein AmtR was knocked out, resulting in an 8.5% increase in L-lysine production (i.e., 52.3 ± 4.31 g/L). Subsequently, the dehydrogenase pathway was upregulated by blocking or weakening the tetrahydrodipicolinate succinylase (DapD)-coding gene dapD and overexpressing the ddh gene to further enhance L-lysine biosynthesis. The final strain XQ-5-W4 could produce 189 ± 8.7 g/L L-lysine with the maximum specific rate (qLys,max.) of 0.35 ± 0.05 g/(g·h) in a 5-L jar fermenter. The L-lysine titer and qLys,max achieved in this study is about 25.2% and 59.1% higher than that of the original strain without enhancement of dehydrogenase pathway, respectively. The results indicated that the dehydrogenase pathway could serve as a breakthrough point to reconstruct the diaminopimelic acid (DAP) pathway and promote L-lysine production.


Assuntos
Corynebacterium glutamicum/metabolismo , Ácido Diaminopimélico/metabolismo , Lisina/metabolismo , Transdução de Sinais/fisiologia , Aciltransferases/metabolismo , Compostos de Amônio/metabolismo , Oxirredutases/metabolismo
16.
Plant Physiol Biochem ; 167: 113-122, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34352514

RESUMO

Nitric oxide (NO) is an important regulator of plant response to cold stress. In this study, NO treatment delayed the development of chilling injury (CI), inhibited the increase in H2O2 content, O2- production rate and decrease in firmness of postharvest peach fruit. Meanwhile, through RNA-seq analysis, NO treatment up-regulated gene expression of PpG-6-PDH, Pp6-PGDH and PpAOX while it down-regulated the expression of PpGPI and PpHK, suggesting that the pentose phosphate respiratory pathway and cyanide-resistant respiratory pathway were promoted and the glycolysis pathway was inhibited. Furthermore, the PpAOX expression was consistent with the trend of PpPOD1/2 expression and H2O2 content, indicating that AOX may play a role in reducing oxidative damage of peach fruit by scavenging H2O2. Thus, it was concluded that NO treatment could induce the cyanide-resistant respiration pathway to enhance antioxidant ability and chilling tolerance in post-harvest peach fruit.


Assuntos
Prunus persica , Antioxidantes , Temperatura Baixa , Frutas , Peróxido de Hidrogênio , Proteínas Mitocondriais , Óxido Nítrico , Oxirredutases , Proteínas de Plantas
17.
Biomolecules ; 11(7)2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34356667

RESUMO

During the last century, anthropogenic activities such as fertilization have led to an increase in pollution in many ecosystems by nitrogen compounds. Consequently, researchers aim to reduce nitrogen pollutants following different strategies. Some haloarchaea, owing to their denitrifier metabolism, have been proposed as good model organisms for the removal of not only nitrate, nitrite, and ammonium, but also (per)chlorates and bromate in brines and saline wastewater. Bacterial denitrification has been extensively described at the physiological, biochemical, and genetic levels. However, their haloarchaea counterparts remain poorly described. In previous work the model structure of nitric oxide reductase was analysed. In this study, a bioinformatic analysis of the sequences and the structural models of the nitrate, nitrite and nitrous oxide reductases has been described for the first time in the haloarchaeon model Haloferax mediterranei. The main residues involved in the catalytic mechanism and in the coordination of the metal centres have been explored to shed light on their structural characterization and classification. These results set the basis for understanding the molecular mechanism for haloarchaeal denitrification, necessary for the use and optimization of these microorganisms in bioremediation of saline environments among other potential applications including bioremediation of industrial waters.


Assuntos
Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Enzimas/metabolismo , Haloferax mediterranei/metabolismo , Coenzimas/metabolismo , Simulação por Computador , Desnitrificação , Enzimas/química , Haloferax mediterranei/enzimologia , Modelos Moleculares , Nitrato Redutase/química , Nitrato Redutase/metabolismo , Nitrito Redutases/química , Nitrito Redutases/metabolismo , Oxirredutases/química , Oxirredutases/metabolismo , Sinais Direcionadores de Proteínas , Alinhamento de Sequência
18.
Dokl Biochem Biophys ; 499(1): 220-224, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34426915

RESUMO

A reusable system for phenol determination in an aqueous medium was obtained by adsorption of extracellular oxidase from fungus Neonothopanus nambi onto modified nanodiamonds (MND) synthesized by detonation. It was found that the enzyme strongly binds to MND and exhibits catalytic activity in the reaction of co-oxidation of phenol with 4-aminoantipyrine without the addition of hydrogen peroxide. In the presence of the MND-oxidase complex, a significantly (by an order of magnitude) higher yield of the reaction product is recorded as compared to the yield in the presence of a free enzyme; the mechanism of the revealed effect is discussed. Model experiments have demonstrated the multiple use of the MND-oxidase complex for testing phenol in aqueous samples. The immobilized enzyme exhibits functional activity during long-term (2 months) storage of the MND-oxidase complex at 4°C. The data obtained create the prerequisites for using the created system in environmental monitoring of water pollution with phenol.


Assuntos
Basidiomycota/enzimologia , Técnicas Biossensoriais/métodos , Espaço Extracelular/enzimologia , Nanodiamantes/química , Oxirredutases/metabolismo , Fenol/análise , Água/química , Basidiomycota/citologia , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Oxirredutases/química
19.
Fish Shellfish Immunol ; 117: 220-227, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34418553

RESUMO

This study aimed to evaluate that dietary protein levels and culture salinity levels affect the health status of juvenile genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Graded protein levels of six diets were prepared, ranging from 18.20% to 49.49% (dry basis), and were used in cultured GIFT at two salinity levels (0‰ and 8‰) for 8 weeks. The results suggested that appropriate protein levels reduced pro-inflammatory gene expressions in the intestine including interleukin 1ß (IL-1ß), interleukin 8 (IL-8) and tumour necrosis factor-α (TNF-α) mRNA levels at two salinity levels (P < 0.05). 8‰ salinity significantly decreased the expression levels of IL-1ß, TNF-α and nuclear factor-kappa B (NF-κB) (P < 0.05). The anti-inflammatory factor interleukin 10 (IL-10) was significantly increased by 36.42% protein level (P < 0.05). Regarding antioxidant capacity, appropriate protein levels and 8‰ salinity significantly improved the antioxidant capacity of fish by regulating the activities of intestinal total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and the levels of glutathione (GSH) and malondialdehyde (MDA). Furthermore, appropriate protein levels and 8‰ salinity also significantly enhanced the antioxidant gene expressions associated with the Nrf2/keap1 signaling pathway by regulating the expression levels of heme oxygenase-1 (HO-1), GPx, catalase (CAT) and superoxide dismutase (SOD). According to GPx activities and the mRNA levels of IL-10, the optimum dietary protein levels for GIFT juveniles were 31.12%-32.18% (0‰) and 34.25-35.38% (8‰) based on second-degree polynomial regression analysis. The present study found that appropriate protein levels and 8‰ culture salinity are critical in maintaining the health of GIFT juveniles by improving antioxidant and immune capacity.


Assuntos
Ciclídeos/imunologia , Proteínas na Dieta/administração & dosagem , Proteínas de Peixes/imunologia , Fator 2 Relacionado a NF-E2/imunologia , Salinidade , Animais , Animais Geneticamente Modificados , Aquicultura , Ciclídeos/genética , Citocinas/imunologia , Expressão Gênica , Intestinos/imunologia , NF-kappa B/imunologia , Oxirredutases/genética , Transdução de Sinais
20.
Biomolecules ; 11(8)2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34439809

RESUMO

Leaf senescence, the last stage of leaf development, is a well-regulated and complex process for investigation. For simplification, dark-induced leaf senescence has frequently been used to mimic the natural senescence of leaves because many typical senescence symptoms, such as chlorophyll (Chl) and protein degradation, also occur under darkness. In this study, we compared the phenotypes of leaf senescence that occurred when detached leaves or intact plants were incubated in darkness to induce senescence. We found that the symptoms of non-programmed cell death (non-PCD) with remaining green coloration occurred more heavily in the senescent leaves of whole plants than in the detached leaves. The pheophorbide a (Pheide a) content was also shown to be much higher in senescent leaves when whole plants were incubated in darkness by analyses of leaf Chl and its metabolic intermediates. In addition, more serious non-PCD occurred and more Pheide a accumulated in senescent leaves during dark incubation if the soil used for plant growth contained more water. Under similar conditions, the non-PCD phenotype was alleviated and the accumulation of Pheide a was reduced by overexpressing 7-hydroxymethyl Chl a (HMChl a) reductase (HCAR). Taken together, we conclude that a high soil water content induced non-PCD by decreasing HCAR activity when whole plants were incubated in darkness to induce senescence; thus, the investigation of the fundamental aspects of biochemistry and the regulation of leaf senescence are affected by using dark-induced leaf senescence.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Clorofila/análogos & derivados , Regulação da Expressão Gênica de Plantas , Oxirredutases/genética , Folhas de Planta/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Morte Celular , Clorofila/metabolismo , Escuridão , Oxirredutases/metabolismo , Fenótipo , Fotossíntese/genética , Células Vegetais/metabolismo , Folhas de Planta/metabolismo , Estabilidade Proteica , Proteólise , Solo/química , Água/metabolismo
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