Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
1.
Int J Mol Sci ; 25(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732144

RESUMO

DNA methylation is a form of epigenetic regulation, having pivotal parts in controlling cellular expansion and expression levels within genes. Although blood DNA methylation has been studied in humans and other species, its prominence in cattle is largely unknown. This study aimed to methodically probe the genomic methylation map of Xinjiang brown (XJB) cattle suffering from bovine respiratory disease (BRD), consequently widening cattle blood methylome ranges. Genome-wide DNA methylation profiling of the XJB blood was investigated through whole-genome bisulfite sequencing (WGBS). Many differentially methylated regions (DMRs) obtained by comparing the cases and controls groups were found within the CG, CHG, and CHH (where H is A, T, or C) sequences (16,765, 7502, and 2656, respectively), encompassing 4334 differentially methylated genes (DMGs). Furthermore, GO/KEGG analyses showed that some DMGs were involved within immune response pathways. Combining WGBS-Seq data and existing RNA-Seq data, we identified 71 significantly differentially methylated (DMGs) and expressed (DEGs) genes (p < 0.05). Next, complementary analyses identified nine DMGs (LTA, STAT3, IKBKG, IRAK1, NOD2, TLR2, TNFRSF1A, and IKBKB) that might be involved in the immune response of XJB cattle infected with respiratory diseases. Although further investigations are needed to confirm their exact implication in the involved immune processes, these genes could potentially be used for a marker-assisted selection of animals resistant to BRD. This study also provides new knowledge regarding epigenetic control for the bovine respiratory immune process.


Assuntos
Metilação de DNA , Predisposição Genética para Doença , Bovinos , Animais , Epigênese Genética , Doenças dos Bovinos/genética , Complexo Respiratório Bovino/genética
2.
Environ Sci Technol ; 57(2): 1157-1166, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36602942

RESUMO

Harmful algae blooms (HABs) frequently occur all over the world and cause great harm to the environment, human health, and aquatic ecosystems. However, owing to their great growth rate and large nutrient intake capacity, algae can enrich a large amount of carbon (CO2) and nutritional elements (N and P) in their biomass. Thus, this could be applied as a robust approach to battle global warming and water eutrophication if the harmful algae biomass was effectively harvested and utilized. Herein, we propose a thermochemical approach to convert algae biomass into a nitrogen-doped electrocatalyst for CO2 reduction. The as-synthesized carbon catalyst exhibits a favorable electrochemical CO2 reduction activity. The key drivers of the environmental impacts in the thermochemical conversion approach with a comparison with the commonly used landfilling approach are identified with life cycle assessment. The former presents much lower environmental burdens in terms of impacts such as freshwater/terrestrial ecotoxicity and human toxicity than the latter. Moreover, if the thermochemical conversion process was successfully applied for biomass conversion worldwide, 2.17 × 108 tons of CO2-eq, 8.42 × 106 tons of N, and 1.21 × 106 tons of P could be removed from the global carbon and other element cycles. Meanwhile, the thermochemical approach is also similar to landfilling in terms of costs. The results from this work provide a brand-new perspective for achieving twofold CO2 utilization and efficiently battling harmful algae blooms.


Assuntos
Dióxido de Carbono , Ecossistema , Humanos , Biomassa , Proliferação Nociva de Algas , Carbono
3.
Anim Biotechnol ; 34(7): 3053-3062, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36244020

RESUMO

The aim of this study was to investigate the selection signatures at a genome-wide level in 'Pishan' sheep using Specific Locus Amplified Fragment (SLAF)-seq. Blood samples from 126 ewes were sequenced using SLAF tags, and the ovarian tissues from 8 ewes (Bashbay sheep, a single litter size group (SG group); 'Pishan' sheep, double litter size group (DG group)) were collected to detect expression levels by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Selection signature analysis was performed using global fixation index (Fst) and nucleotide diversity (π) ratio. A total of 1,192,168 high-quality SLAFs were identified. Notably, 2380 candidate regions under selection using two approaches were identified. A total of 2069 genes were identified, which were involved in dopaminergic synapses, thyroid hormone synthesis, ovarian steroidogenesis and thyroid hormone signalling pathways. Furthermore, Growth Differentiation Factor 9 (GDF9), Period Circadian Regulator 2 (PER2), Thyroid Stimulating Hormone Receptor (TSHR), and Nuclear Receptor Coactivator 1 (NCOA1) reside within these regions and pathways. The expression levels of GDF9 and PER2 genes in sheep tissue of the DG group were significantly higher than those in the SG group. These genes are interesting candidates for litter size and provide a starting point for further identification of conservation strategies for 'Pishan' sheep.


Assuntos
Polimorfismo de Nucleotídeo Único , Hormônios Tireóideos , Gravidez , Ovinos/genética , Animais , Feminino , Tamanho da Ninhada de Vivíparos/genética , Sequência de Bases
4.
Anim Biotechnol ; 34(4): 900-910, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34865605

RESUMO

LncRNAs have recently received special attention due to their critical role in many important biological processes. There are few reports on its regulatory function in sheep fat deposition. In this study, two sheep populations with different tail types in Xinjiang, Bashibai sheep (fat-tailed) and the hybrid population of Bashibai sheep and wild argali (small-tailed) were selected for whole transcriptome sequencing from their tail tissues. First, 728 differentially expressed LncRNAs of tail fat between Bashibai and F2 sheep were identified by RNA-seq. Second, the tissue expression profile and relative expression difference between Bashibai and F2 sheep of 2 of 728 DE LncRNAs were analyzed by RT-PCR. LncRNA-MSTRG.24995 was highly expressed in tail fat, while lncRNA-MSTRG.36913 was highly expressed in subcutaneous fat. In addition, the expressions of LncRNA-MSTRG.24995 and LncRNA-MSTRG.36913 in tail fat of F2 sheep were significantly lower than that of Bashibai sheep, while those patterns in longissimus dorsi, quadriceps femoris and rumen were reversed. Third, the expression pattern of target genes FASN and THRSP in each tissue was similar with that of corresponding LncRNAs. The LncRNA-MSTRG.24995 directly affects tail fat deposition by FASN gene, while the LncRNA-MSTRG.36913 indirectly affects that by THRSP gene. This will help us to understand molecular mechanism of fat tail deposition from transcriptomic perspectives.


Assuntos
RNA Longo não Codificante , Animais , Ovinos/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Cauda , Perfilação da Expressão Gênica/veterinária , Transcriptoma/genética , RNA-Seq
5.
Anim Biotechnol ; 34(7): 2724-2735, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36007548

RESUMO

Donkey milk has high nutritional and medicinal value, but there are few researches in donkey milk traits, especially on genome. The whole lactation of 89 donkeys was recorded and it was found that Xinjiang donkey had good lactation performance while great differences among individuals. In our previous study, four genes including LGALS2, NUMB, ADCY8 and CA8 were identified as milk-associated with Chinese Kazakh house, based on Equine 670k Chip genomic analysis. And then 15 SNPs of the four key genes were conducted for genotyping in Xinjiang donkey in this study, one of Chinese indigenous breed, 14 SNPs were successful classified. And those SNPs were correlation analysis with milk yield of Xinjiang donkeys. The results showed that NUMB g.46709914T > G was significantly correlated with daily milk yield of Xinjiang donkey in the early, middle, and late periods, while ADCY8 g.48366302T > C, CA8 g.89567442T > G and CA8 g.89598328T > A were significantly correlated with lactation in the late periods. These results indicate that NUMB g.46709914T > G can be as markers of candidate genes for lactating traits in donkeys, SNPs of ADCY8 and CA8 as potential. Our findings will not only help confirm key genes for donkey milk traits, but also provide future for genomic selection in donkeys.


Assuntos
Equidae , Leite , Feminino , Cavalos , Animais , Equidae/genética , Lactação/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
6.
Anim Biotechnol ; 34(9): 4680-4686, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37093180

RESUMO

Copy number variation (CNV) is an important member of genetic structural variation that exists widely in animal genomes and is between 50 bp and several Mb in length and widely used in research's of animal genetics and breeding. ZNF679 is an important transcription factor, which has been found association with diseases in the human genome many times. This gene has also been found to be associated with cattle growth traits in previous re-sequencing studies. We tested the CNVs of the ZNF679 gene in 809 individuals from 7 Chinese cattle breeds and tested the association between the CNVs and growth traits in 552 individuals from 5 breeds. The results demonstrated the correlation the correlation between the CNVs of the ZNF679 gene and some Chinese cattle (QC cattle and XN cattle) growth traits. To sum up, this study indicated that ZNF679-CNVs can be used as a candidate gene for molecular genetic marker-assisted selection breeding for cattle growth traits to contribute to the development of genetic improvement of Chinese cattle.


Assuntos
Variações do Número de Cópias de DNA , Regulação da Expressão Gênica , Animais , Bovinos/genética , Humanos , Variações do Número de Cópias de DNA/genética , Fenótipo , Peso Corporal/genética
7.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37833983

RESUMO

Animal skeletal muscle growth is regulated by a complex molecular network including some non-coding RNAs (ncRNAs). In this paper, we review the non-coding RNAs related to the growth and development of common animal skeletal muscles, aiming to provide a reference for the in-depth study of the role of ncRNAs in the development of animal skeletal muscles, and to provide new ideas for the improvement of animal production performance.


Assuntos
RNA Longo não Codificante , RNA não Traduzido , Animais , RNA não Traduzido/genética , Músculo Esquelético , Desenvolvimento Muscular/genética
8.
Int J Mol Sci ; 24(22)2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-38003385

RESUMO

Cardiovascular diseases are a leading cause of worldwide mortality, and exosomes have recently gained attention as key mediators of intercellular communication in these diseases. Exosomes are double-layered lipid vesicles that can carry biomolecules such as miRNAs, lncRNAs, and circRNAs, and the content of exosomes is dependent on the cell they originated from. They can be involved in the pathophysiological processes of cardiovascular diseases and hold potential as diagnostic and monitoring tools. Exosomes mediate intercellular communication, stimulate or inhibit the activity of target cells, and affect myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis. Exosomes can be released from various types of cells, including endothelial cells, smooth muscle cells, cardiomyocytes, fibroblasts, platelets, adipocytes, immune cells, and stem cells. In this review, we highlight the communication between different cell-derived exosomes and cardiovascular cells, with a focus on the roles of RNAs. This provides new insights for further exploring targeted therapies in the clinical management of cardiovascular diseases.


Assuntos
Doenças Cardiovasculares , Exossomos , Humanos , Doenças Cardiovasculares/metabolismo , Células Endoteliais/metabolismo , RNA não Traduzido/metabolismo , Comunicação Celular/genética , Miócitos Cardíacos/metabolismo , Exossomos/metabolismo
9.
Int J Mol Sci ; 24(12)2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-37373126

RESUMO

Adipogenesis is regarded as an intricate network in which multiple transcription factors and signal pathways are involved. Recently, big efforts have focused on understanding the epigenetic mechanisms and their involvement in the regulation of adipocyte development. Multiple studies investigating the regulatory role of non-coding RNAs (ncRNAs) in adipogenesis have been reported so far, especially lncRNA, miRNA, and circRNA. They regulate gene expression at multiple levels through interactions with proteins, DNA, and RNA. Exploring the mechanism of adipogenesis and developments in the field of non-coding RNA may provide a new insight to identify therapeutic targets for obesity and related diseases. Therefore, this article outlines the process of adipogenesis, and discusses updated roles and mechanisms of ncRNAs in the development of adipocytes.


Assuntos
MicroRNAs , RNA Longo não Codificante , Adipogenia/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Adipócitos/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
10.
Int J Mol Sci ; 23(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35269604

RESUMO

Exosomes are a subset of nano-sized extracellular vesicles originating from endosomes. Exosomes mediate cell-to-cell communication with their cargos, which includes mRNAs, miRNAs, lncRNAs, and circRNAs. Exosomal RNAs have cell specificity and reflect the conditions of their donor cells. Notably, their detection in biofluids can be used as a diagnostic marker for various diseases. Exosomal RNAs are ideal biomarkers because their surrounding membranes confer stability and they are detectable in almost all biofluids, which helps to reduce trauma and avoid invasive examinations. However, knowledge of exosomal biomarkers remains scarce. The present review summarizes the biogenesis, secretion, and uptake of exosomes, the current researches exploring exosomal mRNAs, miRNAs, lncRNAs, and circRNAs as potential biomarkers for the diagnosis of human diseases, as well as recent techniques of exosome isolation.


Assuntos
Exossomos , MicroRNAs , RNA Longo não Codificante , Biomarcadores/metabolismo , Biomarcadores Tumorais/metabolismo , Exossomos/genética , Exossomos/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo
11.
Chembiochem ; 22(10): 1765-1768, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33523590

RESUMO

The use of nicotinamide cytosine dinucleotide (NCD), a biocompatible nicotinamide adenosine dinucleotide (NAD) analogue, is of great scientific and biotechnological interest. Several redox enzymes have been devised to favor NCD, and have been successfully applied in creating NCD-dependent redox systems. However, molecular interactions between cofactor and protein have still to be disclosed in order to guide further engineering efforts. Here we report the structural analysis of an NCD-favoring malic enzyme (ME) variant derived from Escherichia coli. The X-ray crystal structure data revealed that the residues located at position 346 and 401 in ME acted as the "gatekeepers" of the adenine moiety binding cavity. When Arg346 was substituted with either acidic or aromatic residues, the corresponding mutants showed substantially reduced NCD preference. Inspired by these observations, we generated Lactobacillus helveticus derived d-lactate dehydrogenase variants at Ile177, the counterpart to Arg346 in ME, and found a similar trend in terms of cofactor preference changes. As many NAD-dependent oxidoreductases share key structural features, our results provide guidance for protein engineering to obtain more NCD-favoring variants.


Assuntos
Proteínas de Bactérias/metabolismo , Malato Desidrogenase/metabolismo , NAD/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , Cristalografia por Raios X , Escherichia coli/enzimologia , L-Lactato Desidrogenase/química , L-Lactato Desidrogenase/genética , L-Lactato Desidrogenase/metabolismo , Lactobacillus helveticus/enzimologia , Malato Desidrogenase/química , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , NAD/metabolismo , Oxirredução
12.
J Environ Manage ; 296: 113128, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34246899

RESUMO

Value-added materials such as biochar and activated carbon that are produced using thermo-chemical conversion of organic waste have gained an emerging interest for the application in the fields of energy and environment because of their low cost and unique physico-chemical properties. Organic waste-derived materials have multifunctional abilities in the field of environment for capturing greenhouse gases and remediation of contaminated soil and water as well as in the field of energy storage and conversion. This review critically evaluates and discusses the current thermo-chemical approaches for upgrading organic waste to value-added carbon materials, performance enhancement of these materials via activation and/or surface modification, and recent research findings related to energy and environmental applications. Moreover, this review provides detailed guidelines for preparing high-performance organic waste-derived materials and insights for their potential applications. Key challenges associated with the sustainable management of organic waste for ecological and socio-economic benefits and potential solutions are also discussed.


Assuntos
Carvão Vegetal , Solo , Poluição Ambiental , Resíduos
13.
Chemistry ; 26(70): 16611-16615, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32815230

RESUMO

Formate dehydrogenase (FDH) has been widely used for the regeneration of the reduced nicotinamide adenine dinucleotide (NADH). To utilize nicotinamide cytosine dinucleotide (NCD) as a non-natural redox cofactor, it remains challenging as NCDH, the reduced form of NCD, has to be efficiently regenerated. Here we demonstrate successful engineering of FDH for NCDH regeneration. Guided by the structural information of FDH from Pseudomonas sp. 101 (pseFDH) and the NAD-pseFDH complex, semi-rational strategies were applied to design mutant libraries and screen for NCD-linked activity. The most active mutant reached a cofactor preference switch from NAD to NCD by 3700-fold. Homology modeling analysis showed that these mutants had reduced cofactor binding pockets and dedicated hydrophobic interactions for NCD. Efficient regeneration of NCDH was implemented by powering an NCD-dependent D-lactate dehydrogenase for stoichiometric and stereospecific reduction of pyruvate to D-lactate at the expense of formate.


Assuntos
Formiato Desidrogenases/química , Formiato Desidrogenases/metabolismo , NAD/metabolismo , Formiato Desidrogenases/genética , L-Lactato Desidrogenase/metabolismo , Oxirredução
14.
Angew Chem Int Ed Engl ; 59(8): 3143-3146, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31845497

RESUMO

A non-natural cofactor and formate driven system for reductive carboxylation of pyruvate is presented. A formate dehydrogenase (FDH) mutant, FDH*, that favors a non-natural redox cofactor, nicotinamide cytosine dinucleotide (NCD), for generation of a dedicated reducing equivalent at the expense of formate were acquired. By coupling FDH* and NCD-dependent malic enzyme (ME*), the successful utilization of formate is demonstrated as both CO2 source and electron donor for reductive carboxylation of pyruvate with a perfect stoichiometry between formate and malate. When 13 C-isotope-labeled formate was used in in vitro trials, up to 53 % of malate had labeled carbon atom. Upon expression of FDH* and ME* in the model host E. coli, the engineered strain produced more malate in the presence of formate and NCD. This work provides an alternative and atom-economic strategy for CO2 fixation where formate is used in lieu of CO2 and offers dedicated reducing power.

15.
Bioorg Med Chem Lett ; 29(12): 1446-1449, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-31006524

RESUMO

Many alcohol dehydrogenases (ADHs) catalyze oxidation of a broad scope of alcohols. When an NAD-dependent ADH oxidizes methanol, albeit at a poor rate, it may be treated as methanol dehydrogenase (MDH). One ADH from Geobacillus stearothermophilus DSM 2334 (GsADH) has been widely used as MDH, but its actual substrate scope remains less characterized. Here we purified recombinant GsADH from Escherichia coli and determined its crystal structure. We collected kinetics data of this enzyme towards a number of short chain alcohols, and found that isopropanol is by far the most favorable substrate. Moreover, molecular docking analysis suggested that substrate preference is mainly attributed to the conformer energy of the protein-substrate complex. Our data clarified the substrate scope of GsADH and provided structural insights, which may facilitate more efficient cofactor regeneration and rational metabolic engineering.


Assuntos
Álcool Desidrogenase/metabolismo , Oxirredutases do Álcool/metabolismo , Sequência de Aminoácidos , Humanos , Simulação de Acoplamento Molecular
16.
Chem Rev ; 117(9): 6367-6398, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28337906

RESUMO

Biomass is increasingly perceived as a renewable resource rather than as an organic solid waste today, as it can be converted to various chemicals, biofuels, and solid biochar using modern processes. In the past few years, pyrolysis has attracted growing interest as a promising versatile platform to convert biomass into valuable resources. However, an efficient and selective conversion process is still difficult to be realized due to the complex nature of biomass, which usually makes the products complicated. Furthermore, various contaminants and inorganic elements (e.g., heavy metals, nitrogen, phosphorus, sulfur, and chlorine) embodied in biomass may be transferred into pyrolysis products or released into the environment, arousing environmental pollution concerns. Understanding their behaviors in biomass pyrolysis is essential to optimizing the pyrolysis process for efficient resource recovery and less environmental pollution. However, there is no comprehensive review so far about the fates of chemical elements in biomass during its pyrolysis. Here, we provide a critical review about the fates of main chemical elements (C, H, O, N, P, Cl, S, and metals) in biomass during its pyrolysis. We overview the research advances about the emission, transformation, and distribution of elements in biomass pyrolysis, discuss the present challenges for resource-oriented conversion and pollution abatement, highlight the importance and significance of understanding the fate of elements during pyrolysis, and outlook the future development directions for process control. The review provides useful information for developing sustainable biomass pyrolysis processes with an improved efficiency and selectivity as well as minimized environmental impacts, and encourages more research efforts from the scientific communities of chemistry, the environment, and energy.


Assuntos
Biomassa , Animais , Humanos , Metais/química , Compostos Orgânicos/química , Temperatura
17.
Small ; 14(34): e1801878, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30063288

RESUMO

The oxygen evolution reaction (OER) catalytic activity of a transition metal oxides/hydroxides based electrocatalyst is related to its pseudocapacitance at potentials lower than the OER standard potential. Thus, a well-defined pseudocapacitance could be a great supplement to boost OER. Herein, a highly pseudocapacitive Ni-Fe-Co hydroxides/N-doped carbon nanoplates (NiCoFe-NC)-based electrocatalyst is synthesized using a facile one-pot solvothermal approach. The NiCoFe-NC has a great pseudocapacitive performance with 1849 F g-1 specific capacitance and 31.5 Wh kg-1 energy density. This material also exhibits an excellent OER catalytic activity comparable to the benchmark RuO2 catalysts (an initiating overpotential of 160 mV and delivering 10 mA cm-2 current density at 250 mV, with a Tafel slope of 31 mV dec-1 ). The catalytic performance of the optimized NiCoFe-NC catalyst could keep 24 h. X-ray photoelectron spectroscopy, electrochemically active surface area, and other physicochemical and electrochemical analyses reveal that its great OER catalytic activity is ascribed to the Ni-Co hydroxides with modular 2-Dimensional layered structure, the synergistic interactions among the Fe(III) species and Ni, Co metal centers, and the improved hydrophily endowed by the incorporation of N-doped carbon hydrogel. This work might provide a useful and general strategy to design and synthesize high-performance metal (hydr)oxides OER electrocatalysts.

18.
Appl Environ Microbiol ; 83(13)2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28455340

RESUMO

NAD and its reduced form NADH function as essential redox cofactors and have major roles in determining cellular metabolic features. NAD can be synthesized through the deamidated and amidated pathways, for which the key reaction involves adenylylation of nicotinic acid mononucleotide (NaMN) and nicotinamide mononucleotide (NMN), respectively. In Escherichia coli, NAD de novo biosynthesis depends on the protein NadD-catalyzed adenylylation of NaMN to nicotinic acid adenine dinucleotide (NaAD), followed by NAD synthase-catalyzed amidation. In this study, we engineered NadD to favor NMN for improved amidated pathway activity. We designed NadD mutant libraries, screened by a malic enzyme-coupled colorimetric assay, and identified two variants, 11B4 (Y84V/Y118D) and 16D8 (A86W/Y118N), with a high preference for NMN. Whereas in the presence of NMN both variants were capable of enabling the viability of cells of E. coli BW25113-derived NAD-auxotrophic strain YJE003, for which the last step of the deamidated pathway is blocked, the 16D8 expression strain could grow without exogenous NMN and accumulated a higher cellular NAD(H) level than BW25113 in the stationary phase. These mutants established fully active amidated NAD biosynthesis and offered a new opportunity to manipulate NAD metabolism for biocatalysis and metabolic engineering.IMPORTANCE Adenylylation of nicotinic acid mononucleotide (NaMN) and adenylylation of nicotinamide mononucleotide (NMN), respectively, are the key steps in the deamidated and amidated pathways for NAD biosynthesis. In most organisms, canonical NAD biosynthesis follows the deamidated pathway. Here we engineered Escherichia coli NaMN adenylyltransferase to favor NMN and expressed the mutant enzyme in an NAD-auxotrophic E. coli strain that has the last step of the deamidated pathway blocked. The engineered strain survived in M9 medium, which indicated the implementation of a functional amidated pathway for NAD biosynthesis. These results enrich our understanding of NAD biosynthesis and are valuable for manipulation of NAD homeostasis for metabolic engineering.


Assuntos
Escherichia coli/enzimologia , NAD/biossíntese , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Mutação , NAD/análogos & derivados , NAD/metabolismo , Mononucleotídeo de Nicotinamida/análogos & derivados , Mononucleotídeo de Nicotinamida/metabolismo , Nicotinamida-Nucleotídeo Adenililtransferase/química , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Engenharia de Proteínas , Especificidade por Substrato
19.
Environ Sci Technol ; 51(17): 10081-10089, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28753301

RESUMO

Lead (Pb) pollution in natural water bodies is an environmental concern due to toxic effects on aquatic ecosystems and human health, while adsorption is an effective approach to remove Pb from the water. Surface interactions between adsorbents and adsorbates play a dominant role in the adsorption process, and properly engineering a material's surface property is critical to the improvement of adsorption performance. In this study, the magnesium oxide (MgO) nanoparticles stabilized on the N-doped biochar (MgO@N-biochar) were synthesized by one-pot fast pyrolysis of an MgCl2-loaded N-enriched hydrophyte biomass as a way to increase the exchangeable ions and N-containing functional groups and facilitate the adsorption of Pb2+. The as-synthesized MgO@N-biochar has a high performance with Pb in an aqueous solution with a large adsorption capacity (893 mg/g), a very short equilibrium time (<10 min), and a large throughput (∼4450 BV). Results show that this excellent adsorption performance can be maintained with various environmentally relevant interferences including pH, natural organic matter, and other metal ions, suggesting that the material may be suitable for the treatment of wastewater, natural bodies of water, and even drinking water. In addition, MgO@N-biochar quickly and efficiently removed Cd2+ and tetracycline. Multiple characterizations and comparative tests have been performed to demonstrate the surface adsorption and ion exchange contributed to partial Pb adsorption, and it can be inferred from these results that the high performance of MgO@N-biochar is mainly due to the surface coordination of Pb2+ and C═O or O═C-O, pyridinic, pyridonic, and pyrrolic N. This work suggests that engineering surface functional groups of biochar may be crucial for the development of high performance heavy metal adsorbents.


Assuntos
Carvão Vegetal , Óxido de Magnésio , Metais Pesados/química , Nitrogênio , Adsorção , Água Potável , Purificação da Água
20.
New Phytol ; 210(2): 525-34, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26682704

RESUMO

Cytochromes P450 (CYPs) play a key role in generating the structural diversity of terpenoids, the largest group of plant natural products. However, functional characterization of CYPs has been challenging because of the expansive families found in plant genomes, diverse reactivity and inaccessibility of their substrates and products. Here we present the characterization of two CYPs, CYP76AH3 and CYP76AK1, which act sequentially to form a bifurcating pathway for the biosynthesis of tanshinones, the oxygenated diterpenoids from the Chinese medicinal plant Danshen (Salvia miltiorrhiza). These CYPs had similar transcription profiles to that of the known gene responsible for tanshinone production in elicited Danshen hairy roots. Biochemical and RNA interference studies demonstrated that both CYPs are promiscuous. CYP76AH3 oxidizes ferruginol at two different carbon centers, and CYP76AK1 hydroxylates C-20 of two of the resulting intermediates. Together, these convert ferruginol into 11,20-dihydroxy ferruginol and 11,20-dihydroxy sugiol en route to tanshinones. Moreover, we demonstrated the utility of these CYPs by engineering yeast for heterologous production of six oxygenated diterpenoids, which in turn enabled structural characterization of three novel compounds produced by CYP-mediated oxidation. Our results highlight the incorporation of multiple CYPs into diterpenoid metabolic engineering, and a continuing trend of CYP promiscuity generating complex networks in terpenoid biosynthesis.


Assuntos
Abietanos/metabolismo , Vias Biossintéticas , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Plantas/metabolismo , Salvia miltiorrhiza/metabolismo , Abietanos/química , Cromatografia Líquida , Sistema Enzimático do Citocromo P-450/química , Regulação da Expressão Gênica de Plantas , Engenharia Genética , Espectrometria de Massas , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Saccharomyces cerevisiae/metabolismo , Salvia miltiorrhiza/enzimologia , Salvia miltiorrhiza/genética , Homologia Estrutural de Proteína
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA