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1.
Sci Total Environ ; 951: 175814, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39197773

RESUMO

Anaerobic digestion provides a solution to the inefficient use of carbon resources caused by improper disposal of corn stover-based ethanol stillage (CES). In this regard, we developed a single-chamber anaerobic digestion integrated microbial electrolysis cells system (AD-MEC) to convert CES into biogas while simultaneously upgrading biogas in-situ by employing voltages ranging from 0 to 2.5 V. Our results demonstrated that applying 1.0 V increased the CH4 yield by 55 % and upgraded the CH4 content in-situ to 82 %. This voltage also promoted the well-formed biofilm on the electrodes, resulting in a 20-fold increase in current. However, inhibition was observed at high voltages (1.5-2.5 V), suppressing syntrophic organic acid-oxidizing bacteria (SOB). The dissociation between SOB and methanogens led to accumulation of propionic and butyric acid, which, in turn, inhibited methanogens. The degradation of CES was accelerated by unclassified_o_norank_c_Desulfuromonadia on the anode, likely leading to an increase in mixotrophic methanogenesis due to the synergistic interaction among Aminobacterium, Sedimentibacter, and Methanosarcina. Furthermore, the enrichment of electroactive bacteria (EB) such as Enterococcus and Desulfomicrobium likely facilitates direct interspecies electron transfer to Methanobacterium, thereby promoting the conversion of CO2 to CH4 through hydrogenotrophic methanogenesis. Rather than initially stimulating the EB in the bulk solution to accelerate the start-up process of AD, our study revealed that applying mild voltage up to 1.0 V tended to mitigate the negative impact on the original microorganisms, as it gradually enriched EB on the electrode, thereby enhancing biogas production.


Assuntos
Biocombustíveis , Eletrólise , Etanol , Metano , Metano/metabolismo , Anaerobiose , Etanol/metabolismo , Reatores Biológicos , Celulose/metabolismo
2.
Huan Jing Ke Xue ; 45(8): 4520-4528, 2024 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-39168672

RESUMO

To deepen the recognition of changes in industrial water use with socio-economic development, a "double-layer nested" structural decomposition analysis has been proposed to decompose the influence of the drivers of industrial water use change by sectors in China from 2002 to 2020. The results showed that the scale expansion factors represented by consumption, investment, and export were the main factors for the growth of industrial water use in different sectors, among which the expansion effect of per capita consumption grew faster. Additionally, there were obvious differences in the major drivers of industrial scale expansion between different sectors, which directly drove the industrial structure change. The production process water use effect and water reuse effect were the main factors to curb the growth of industrial water use. The accumulation of both had completely offset the positive effect of industrial scale expansion during the period, reducing industrial water consumption by 11.2 billion m3. However, the production process water use changes in metal extraction, smelting, and processing and energy processing sectors such as electric power had a smaller negative effect, leading to the potential for improving industrial water efficiency solely through a relatively small improvement in water resource reuse. Therefore, it is necessary to strengthen industrial water conservation management based on the differences in the impact of various sectors to promote the transformation and upgradation of industrial production and consumption structures, and to avoid another increase in industrial water use in China.

3.
Biotechnol Adv ; 73: 108372, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38714276

RESUMO

Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.


Assuntos
Fontes de Energia Bioelétrica , Biocombustíveis , Eletrólise , Anaerobiose , Fontes de Energia Bioelétrica/microbiologia , Reatores Biológicos , Metano/metabolismo
4.
J Colloid Interface Sci ; 660: 1048-1057, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38220495

RESUMO

Adsorption is considered to be one of the most effective methods to remove radioiodine from the solution. However, developing highly efficient adsorbents and the rapid recovery of the used adsorbents is still a challenge. Here, a series of Cu/Fe3O4 bimetallic mutual-doping magnetic aerogels (Cu/Fe3O4-BMMA) were synthesized. Based on the in-situ bimetallic co-gelation process, the high dispersion of Cu in the aerogel was realized, providing conditions for the efficient elimination of I2. The Fe3+ in the initial gel was reduced to magnetic Fe3O4 during the preparation process, allowing for the quick recovery of the adsorbent through the application of a magnetic field. The adsorption experiments showed that Cu/Fe3O4-BMMA has good I2 adsorption capacity (631.3 mg/g) and fast capture kinetics (equilibrium time < 30 min). In addition, Cu/Fe3O4-BMMA was able to effectively remove trace I2 in the solution from ppm level (1.0 ppm) down to ppb level (≤30 ppb). The adsorbed I2 was converted into stable CuI, avoiding secondary pollution due to desorption. Overall, this study provides a potentially efficient iodine capture material for long-term decay storage of radioactive iodine.

5.
J Environ Radioact ; 265: 107211, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37331177

RESUMO

Due to the critical importance of capturing radioiodine from aquatic environments for human health and ecosystems, developing highly efficient adsorbent materials with rapid kinetics for capturing iodide ions in aqueous solutions is urgently needed. Although extensive research has been conducted on iodine adsorption in gas and organic phases, limited research has been dedicated to adsorption in aqueous solutions. An effective technique for removing iodide was proposed using Ag@Cu-based MOFs synthesized by incorporating Ag into calcined HKUST-1 with varying mass ratios of Ag/Cu-C. Extensive characterization using SEM, XRD, XPS, and nitrogen adsorption-desorption analysis confirmed successful incorporation of Ag in Cu-C. Batch adsorption experiments were conducted, demonstrating that the 5% Ag@Cu-C material exhibited a high adsorption capacity of 247.1 mg g-1 at pH 3. Mechanism investigations revealed that Cu0 and dissolved oxygen in water generate Cu2O and H2O2, while Ag and a small amount of CuO generate Ag2O and Cu2O. Furthermore, iodide ions in the solution are captured by Cu+ and Ag+ adsorption sites. These findings highlighted the potential of Ag@Cu-based MOFs as highly effective adsorbents for iodine anions removal in radioactive wastewater.


Assuntos
Iodo , Monitoramento de Radiação , Poluentes Químicos da Água , Humanos , Iodetos , Radioisótopos do Iodo/análise , Ecossistema , Peróxido de Hidrogênio , Água/química , Poluentes Químicos da Água/análise , Adsorção , Cinética , Soluções
6.
Curr Opin Allergy Clin Immunol ; 23(4): 334-340, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37357787

RESUMO

PURPOSE OF REVIEW: This review aimed to introduce the pharmacotherapy of allergic rhinitis according to the 2022 updated Chinese guidelines. RECENT FINDINGS: Despite recent advances in basic and clinical research worldwide, pharmacotherapy remains a mainstream in allergic rhinitis treatment. Usually, the first-line drugs, involving intranasal corticosteroids, second-generation oral and intranasal H1-antihistamines, or leukotriene receptor antagonists, can achieve acceptable outcomes in the treatment of allergic rhinitis. The second-line drugs, such as oral corticosteroids, intranasal decongestants and intranasal anticholinergics, can assist in controlling severe symptoms, like nasal congestion/blockage and watery rhinorrhea. For those with moderate-to-severe allergic rhinitis, evidence-based stepwise strategies are suitable, in which the types and dosages of drugs are de-escalated or upgraded according to their therapeutic efficacy. Meanwhile, omalizumab, a novel biological agent, has burgeoned to satisfy the need of patients. SUMMARY: This review highlights the staples in Chinese guidelines about the pharmacotherapy for allergic rhinitis to better understand the guidelines and promote the clinical practice.


Assuntos
Rinite Alérgica Perene , Rinite Alérgica , Humanos , Rinite Alérgica Perene/tratamento farmacológico , Rinite Alérgica Perene/diagnóstico , Rinite Alérgica/diagnóstico , Rinite Alérgica/tratamento farmacológico , Omalizumab/uso terapêutico , Corticosteroides/uso terapêutico , Antagonistas de Leucotrienos/uso terapêutico , Antagonistas dos Receptores Histamínicos H1/uso terapêutico
7.
Bioresour Technol ; 385: 129375, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37352987

RESUMO

Biorefinery can be promoted by building accurate machine learning models. This work proposed a strategy to enhance model's generalization ability and overcome insufficient data conditions for mixed sugar fermentation simulation. Multiple inputs single output models, using initial glucose, initial xylose, and time together as inputs, have higher generalization ability than single input single output models with time as sole input in predicting glucose, xylose, ethanol, or biomass separately. Multiple inputs multiple outputs models, integrating outputs, enhanced model accuracy and resulted in an average R2 at 0.99. To overcome data insufficiency conditions, consensus yeast (CY) model, through consolidating data from 4 yeasts, obtained R2 at 0.90. By adjusting the pretrained CY model, the model can save more than 50% data and get R2 at 0.95 and 0.93 for yeast and bacterial fermentation simulation. The strategy can expand the application range and save costs of data curation for ANN models.


Assuntos
Saccharomyces cerevisiae , Xilose , Fermentação , Glucose , Aprendizado de Máquina
8.
Neural Regen Res ; 18(3): 671-682, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36018193

RESUMO

The functional properties of endogenous Schwann cells (SCs) during nerve repair are dynamic. Optimizing the functional properties of SCs at different stages of nerve repair may have therapeutic benefit in improving the repair of damaged nerves. Previous studies showed that miR-221-3p promotes the proliferation and migration of SCs, and miR-338-3p promotes the myelination of SCs. In this study, we established rat models of sciatic nerve injury by bridging the transected sciatic nerve with a silicone tube. We injected a miR-221 lentiviral vector system together with a doxycycline-inducible Tet-On miR-338 lentiviral vector system into the cavity of nerve conduits of nerve stumps to sequentially regulate the biological function of endogenous SCs at different stages of nerve regeneration. We found that the biological function of SCs was sequentially regulated, the diameter and density of myelinated axons were increased, the expression levels of NF200 and myelin basic protein were increased, and the function of injured peripheral nerve was improved using this system. miRNA Target Prediction Database prediction, Nanopore whole transcriptome sequencing, quantitative PCR, and dual luciferase reporter gene assay results predicted and verified Cdkn1b and Nrp1 as target genes of miR-221-3p and miR-338-3p, respectively, and their regulatory effects on SCs were confirmed in vitro. In conclusion, here we established a new method to enhance nerve regeneration through sequential regulation of biological functions of endogenous SCs, which establishes a new concept and model for the treatment of peripheral nerve injury. The findings from this study will provide direct guiding significance for clinical treatment of sciatic nerve injury.

9.
Zhen Ci Yan Jiu ; 45(9): 740-5, 2020 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-32959558

RESUMO

OBJECTIVE: To observe changes of microcirculation in the superficial regions of acupoints of the three Yin meridians of foot during the menstrual cycle in young college students, so as to provide experimental evidence for explaining the saying of traditional Chinese medicine that acupoints reflect the state of physiological and pathological activities of the internal organs. METHODS: Ninety healthy female volunteer college students were recruited in the present study. The subjects were asked to take a supine position on an examination couch to expose the Yuan-primary acupoints Taixi (KI3), Taibai (SP3) and Taichong (LR3), and Xi-cleft acupoints Shuiquan (KI5), Diji (SP8) and Zhongdu (LR6) which are related to the uterus of the three Yin meridians of foot, the crossing acupoints of the three Yin meridians of foot Sanyinjiao (SP6), non-specific acupoint of the Spleen meridian Xuehai (SP10), non-related meridian acupoint Xuanzhong (GB39) and non-meridian-non-acupoint (being at the same level of GB39, between the Stomach and Gallbladder meridians on the lateral aspect of the lower leg). The laser speckle blood flow imaging technique was used to detect the state of microcirculation (average blood perfusion volume) during menstrual, follicular, ovulatory and luteal phases. RESULTS: The average blood perfusion volume (ABPV) of the right SP8 region was significantly lower in the menstrual phase than in the ovulation and luteal phases (P<0.05), and in the follicular phase than in the ovulation phase (P<0.05). In the left LR6 region, the ABPV was obviously lower in the menstrual period than in the follicular, ovulation and luteal phases (P<0.05). In the SP8, SP6, KI3 and KI5 regions, the ABPV was significantly higher in each of the 4 phases on the left side than on the right side (P<0.05). In the right GB39, the ABPV in each of the 4 phases was apparently higher on the right side than on the left side (P<0.05). In the SP10 region, the ABPV was considerably higher on the left side than on the right side in the ovulation period (P<0.05). The ABPV of SP3 in the menstrual phase and that of the non-acupoint in the luteal phase were significantly higher on the right side than on the left side (P<0.05). CONCLUSION: The blood perfusion of microcirculation in the superficial tissues of Xi-cleft acupoints SP8 and LR6 is obviously lower in the menstrual phase than in both of the ovulation and luteal phases in healthy young college students, which may specifically reflect the periodical activities of the uterus in the physiological state, and provide a basis of acupoint selection for menstrual healthy care.


Assuntos
Pontos de Acupuntura , Meridianos , Feminino , Humanos , Perna (Membro) , Menstruação , Microcirculação
10.
Rev Sci Instrum ; 91(8): 083102, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32872918

RESUMO

InGaAs/InP single-photon detectors (SPDs) are widely used for near-infrared photon counting in practical applications. Photon detection efficiency (PDE) is one of the most important parameters for SPD characterization, and therefore, increasing PDE consistently plays a central role in both industrial development and academic research. Here, we present the implementation of high-frequency gating InGaAs/InP SPDs with a PDE as high as 60% at 1550 nm. On one hand, we optimize the structure design and device fabrication of InGaAs/InP single-photon avalanche diodes with an additional dielectric-metal reflection layer to relatively increase the absorption efficiency of incident photons by ∼20%. On the other hand, we develop a monolithic readout circuit of weak avalanche extraction to minimize the parasitic capacitance for the suppression of the afterpulsing effect. With 1.25 GHz sine wave gating and optimized gate amplitude and operation temperature, the SPD is characterized to reach a PDE of 60% with a dark count rate (DCR) of 340 kcps. For practical use, given 3 kcps DCR as a reference, the PDE reaches ∼40% PDE with an afterpulse probability of 5.5%, which can significantly improve the performance for the near-infrared SPD-based applications.

12.
J Virol ; 88(18): 10934-45, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25008936

RESUMO

UNLABELLED: Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly infectious pathogen that causes severe diseases in pigs and great economic losses to the swine industry worldwide. Type I interferons (IFNs) play a crucial role in antiviral immunity. In the present study, we demonstrated that infection with the highly pathogenic PRRSV strain JXwn06 antagonized type I IFN expression induced by poly(I·C) in both porcine alveolar macrophages (PAMs) and blood monocyte-derived macrophages (BMo). Subsequently, we showed that the inhibition of poly(I·C)-induced IFN-ß production by PRRSV was dependent on the blocking of NF-κB signaling pathways. By screening PRRSV nonstructural and structural proteins, we demonstrated that nonstructural protein 4 (nsp4), a viral 3C-like serine protease, significantly suppressed IFN-ß expression. Moreover, we verified that nsp4 inhibited NF-κB activation induced by signaling molecules, including RIG-I, VISA, TRIF, and IKKß. nsp4 was shown to target the NF-κB essential modulator (NEMO) at the E349-S350 site to mediate its cleavage. Importantly, nsp4 mutants with defective protease activity abolished its ability to cleave NEMO and inhibit IFN-ß production. These findings might have implications for our understanding of PRRSV pathogenesis and its mechanisms for evading the host immune response. IMPORTANCE: Porcine reproductive and respiratory syndrome virus (PRRSV) is a major agent of respiratory diseases in pigs. Like many other viruses, PRRSV has evolved a variety of strategies to evade host antiviral innate immunity for survival and propagation. In this study, we show that PRRSV nsp4 is a novel antagonist of the NF-κB signaling pathway, which is responsible for regulating the expression of type I interferons and other crucial cytokines. We then investigated the underlying mechanism used by nsp4 to suppress NF-κB-mediated IFN-ß production. We found that nsp4 interfered with the NF-κB signaling pathway through the cleavage of NEMO (a key regulator of NF-κB signaling) at the E349-S350 site, leading to the downregulation of IFN-ß production induced by poly(I·C). The data presented here may help us to better understand PRRSV pathogenesis.


Assuntos
Interferon beta/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Síndrome Respiratória e Reprodutiva Suína/metabolismo , Vírus da Síndrome Respiratória e Reprodutiva Suína/metabolismo , Proteínas não Estruturais Virais/metabolismo , Animais , Regulação para Baixo , Interações Hospedeiro-Patógeno , Interferon beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Macrófagos/metabolismo , Macrófagos/virologia , NF-kappa B/genética , NF-kappa B/metabolismo , Síndrome Respiratória e Reprodutiva Suína/genética , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Transdução de Sinais , Suínos , Proteínas não Estruturais Virais/genética
13.
PLoS One ; 8(7): e69387, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23936003

RESUMO

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease in pigs caused by PRRS virus (PRRSV). Although PRRSV infection-induced cell apoptosis has been established, the related viral protein is still unknown. Here, we reported that PRRSV nonstructural protein 4 (nsp4) was a critical apoptosis inducer. Nsp4 could activate caspase-3, -8, and -9. Using truncated constructs without different domains in nsp4, we demonstrated that the full-length of nsp4 structure was required for its apoptosis-inducing activity. Furthermore, using site-directed mutagenesis to inactivate the 3C-like serine protease activity of nsp4, we showed that nsp4-induced apoptosis was dependent on its serine protease activity. The ability of nsp4 to induce apoptosis was significantly impaired by His39, Asp64, and Ser118 mutations, suggesting that His39, Asp64, and Ser118 were essential for nsp4 to trigger apoptosis. In conclusion, our present work showed that PRRSV nsp4 could induce apoptosis in host cells and might be partially responsible for the apoptosis induced by PRRSV infection. PRRSV 3C-like protease-mediated apoptosis represents the first report in the genus Arterivirus, family Arteriviridae.


Assuntos
Apoptose/efeitos dos fármacos , Vírus da Síndrome Respiratória e Reprodutiva Suína/metabolismo , Serina Proteases/metabolismo , Proteínas Virais/farmacologia , Aminoácidos/metabolismo , Animais , Biocatálise/efeitos dos fármacos , Células COS , Caspases/metabolismo , Chlorocebus aethiops , Ativação Enzimática/efeitos dos fármacos , Células HeLa , Humanos , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/enzimologia , Macrófagos Alveolares/patologia , Macrófagos Alveolares/virologia , Síndrome Respiratória e Reprodutiva Suína/patologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Deleção de Sequência , Suínos , Transfecção , Proteínas Virais/metabolismo
14.
Vet Microbiol ; 156(1-2): 200-4, 2012 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-22051445

RESUMO

The amino acid sequence (TAVSPTTLR, 829-837aa) on the glycoprotein E2 of classical swine fever virus (CSFV) is a conserved and linear neutralizing epitope. In the present study, two peptides were constructed based the core sequence of this neutralizing epitope, the dendrimeric peptide (Th-B(4)) containing four copies of B cell epitope fused to one copy of promiscuous T helper (Th) cell epitope and the peptide Th-B containing a single copy of B cell epitope fused to one copy of Th cell epitope. The dendrimeric peptide Th-B(4) elicited high titers of neutralizing antibodies as detected in an indirect ELISA, blocking ELISA and neutralization test and induced a complete protection against CSFV C strain in rabbits. The Th-B elicited low titers of neutralizing antibodies and did not induce a protection in rabbits. These results suggest that the dendrimeric peptide Th-B(4) may be a promising marker vaccine candidate against CSFV and the multimerization is a requirement for development of a peptide vaccine.


Assuntos
Vírus da Febre Suína Clássica/imunologia , Peste Suína Clássica/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais/imunologia , Peste Suína Clássica/imunologia , Ensaio de Imunoadsorção Enzimática , Epitopos de Linfócito B/química , Epitopos de Linfócito B/imunologia , Testes de Neutralização , Coelhos , Suínos , Vacinas de Subunidades Antigênicas/química , Vacinas de Subunidades Antigênicas/imunologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Vacinas Virais/química
15.
Virus Res ; 158(1-2): 108-15, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21458510

RESUMO

The development of cell-mediated immunity has been known extremely important in clearing porcine reproductive and respiratory syndrome virus (PRRSV) in infected pigs. However, the PRRS immunology regarding the interaction of T-cells and PRRSV proteins is poorly understood. To identify the T-cell immunodominant epitopes on the membrane (M) protein of PRRSV, a series of 31 overlapping pentadecapeptides covering the entire M protein were designed and synthesized. These peptides were screened by ELIspot analysis for their capabilities to elicit interferon-gamma (IFN-γ) responses in the peripheral blood mononuclear cells (PBMCs), which were collected from pigs immunized with attenuated PRRSV HuN4-F112 strain and challenged with highly pathogenic HuN4 strain. After three rounds of screening, 4 peptides (M3, M6, M8 and M12) were shown to elicit high expression of IFN-γ. The stimulation of high IFN-γ transcription in PBMCs by these 4 peptides was further confirmed in real-time PCR. The sequence alignment revealed that the epitope represented by peptide M6 was fully conserved in all of examined 42 North American genotype II PRRSV isolates and the epitopes represented by peptides M3, M8 and M12 showed 2-4 amino acid replacements. The finding of 4 T-cell immunodominant epitopes in the M protein of PRRSV will be beneficial to the understanding of the development of cell-mediated immunity.


Assuntos
Epitopos de Linfócito T/imunologia , Epitopos Imunodominantes/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Proteínas da Matriz Viral/imunologia , Animais , ELISPOT , Mapeamento de Epitopos , Interferon gama/metabolismo , Leucócitos Mononucleares/imunologia , Suínos
16.
Biotechnol Lett ; 32(12): 1905-10, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20865444

RESUMO

PURPOSE OF WORK: The non-structural protein 4 (Nsp4) of porcine reproductive and respiratory syndrome virus (PRRSV) functions as a 3C-like proteinase (3CLpro) and plays a pivotal role in gene expression and replication. We have examined the biochemical properties of PRRSV 3CLpro and identified those amino acid residues involved in its catalytic activity as a prelude to developing anti-PRRSV strategies. The 3C-like proteinase (3CLpro) of porcine reproductive and respiratory syndrome virus (PRRSV) was expressed in Escherichia coli and characterized. The optimal temperature and pH for its proteolytic activity were 8°C and 7.5, respectively. Na(+) (1000 mM) and K(+) (500 mM) were not inhibitory to its activity but Cu(2+), Zn(2+), PMSF and EDTA were significantly inhibitory. His(39), Asp(64) and Ser(118) residues were identified to form the catalytic triad of PRRSV 3CLpro by a series of site-directed mutagenesis analysis.


Assuntos
Aminoácidos/genética , Domínio Catalítico , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Vírus da Síndrome Respiratória e Reprodutiva Suína/enzimologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Temperatura Baixa , Cisteína Endopeptidases/química , Inibidores Enzimáticos/metabolismo , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Concentração de Íons de Hidrogênio , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
17.
Virus Res ; 144(1-2): 136-44, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19406176

RESUMO

Since April 2006, swine herds have experienced the outbreaks of a highly pathogenic porcine reproductive and respiratory syndrome (PRRS) in China. To explore the possible mechanism of the emergence of the highly pathogenic PRRS and more fully understand the extent of genetic diversity of PRRSV in China, we analyzed the ORF5 gene sequences of 159 representative PRRSV isolates in 16 provinces from 2006 to 2008. Sequence and phylogenetic analyses showed that all these 159 isolates belonged to the North American genotype and were further divided into six subgenotypes; 140 of 159 isolates were closely related to the highly pathogenic PRRSV with 98.5-100% nucleotide and 98.3-100% amino acid sequence identities and belonged to Subgenotype I; and 3, 8, 4, 3, 1 of 159 isolates were part of Subgenotypes II-VI, respectively. Amino acid analysis of the GP5 protein revealed that all the isolates in Subgenotypes I-III were found to be highly variable in the primary neutralizing epitope; most of the isolates in Subgenotypes I and IV had more glycosylation sites than those in Subgenotypes II, III, V and VI; and 1, 5, and 9 unique amino acid mutations were observed in Subgenotypes I, IV and VI, respectively. In conclusion, our study provides the evidence of coexistence of six different subgenotype isolates in pigs in China from 2006 to 2008, and emphasizes the importance of reinforcing PRRSV surveillance, especially after the emergence of highly pathogenic PRRS in China.


Assuntos
Surtos de Doenças , Polimorfismo Genético , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , China/epidemiologia , Análise por Conglomerados , Genótipo , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , RNA Viral/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Suínos/virologia , Proteínas do Envelope Viral
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