Base de dados : MEDLINE
Pesquisa : D02.455.326.146.770 [Categoria DeCS]
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  1 / 1337 MEDLINE  
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[PMID]:29195373
[Au] Autor:Szabra D; Prokopiuk A; Mikolajczyk J; Ligor T; Buszewski B; Bielecki Z
[Ad] Endereço:Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego St., 00-908 Warsaw, Poland.
[Ti] Título:Air sampling unit for breath analyzers.
[So] Source:Rev Sci Instrum;88(11):115006, 2017 Nov.
[Is] ISSN:1089-7623
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The paper presents a portable breath sampling unit (BSU) for human breath analyzers. The developed unit can be used to probe air from the upper airway and alveolar for clinical and science studies. The BSU is able to operate as a patient interface device for most types of breath analyzers. Its main task is to separate and to collect the selected phases of the exhaled air. To monitor the so-called I, II, or III phase and to identify the airflow from the upper and lower parts of the human respiratory system, the unit performs measurements of the exhaled CO (ECO ) in the concentration range of 0%-20% (0-150 mm Hg). It can work in both on-line and off-line modes according to American Thoracic Society/European Respiratory Society standards. A Tedlar bag with a volume of 5 dm is mounted as a BSU sample container. This volume allows us to collect ca. 1-25 selected breath phases. At the user panel, each step of the unit operation is visualized by LED indicators. This helps us to regulate the natural breathing cycle of the patient. There is also an operator's panel to ensure monitoring and configuration setup of the unit parameters. The operation of the breath sampling unit was preliminarily verified using the gas chromatography/mass spectrometry (GC/MS) laboratory setup. At this setup, volatile organic compounds were extracted by solid phase microextraction. The tests were performed by the comparison of GC/MS signals from both exhaled nitric oxide and isoprene analyses for three breath phases. The functionality of the unit was proven because there was an observed increase in the signal level in the case of the III phase (approximately 40%). The described work made it possible to construct a prototype of a very efficient breath sampling unit dedicated to breath sample analyzers.
[Mh] Termos MeSH primário: Testes Respiratórios/instrumentação
Cromatografia Gasosa-Espectrometria de Massas
Microextração em Fase Sólida
[Mh] Termos MeSH secundário: Butadienos/análise
Hemiterpenos/análise
Seres Humanos
Óxido Nítrico/análise
Pentanos/análise
Compostos Orgânicos Voláteis/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Butadienes); 0 (Hemiterpenes); 0 (Pentanes); 0 (Volatile Organic Compounds); 0A62964IBU (isoprene); 31C4KY9ESH (Nitric Oxide)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180209
[Lr] Data última revisão:
180209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171203
[St] Status:MEDLINE
[do] DOI:10.1063/1.4995502


  2 / 1337 MEDLINE  
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[PMID]:28803474
[Au] Autor:Tanaka S; Shiomi S; Ishikawa H
[Ad] Endereço:Department of Chemistry, Graduate School of Science and Technology, Kumamoto University , 2-39-1, Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.
[Ti] Título:Bioinspired Indole Prenylation Reactions in Water.
[So] Source:J Nat Prod;80(8):2371-2378, 2017 Aug 25.
[Is] ISSN:1520-6025
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Isoprene units derived from dimethylallyl diphosphate (DMAPP) are an important motif in many natural products including terpenoids, carotenoids, steroids, and natural rubber. Understanding the chemical characteristics of DMAPP is an important topic in natural products chemistry, organic chemistry, and biochemistry. We have developed a direct bioinspired indole prenylation reaction using DMAPP or its equivalents as the electrophile in homogeneous aqueous acidic media in the absence of enzyme to provide prenylated indole products. After establishing the bioinspired indole prenylation reaction, this was then used to achieve the synthesis of a series of natural products, namely, N-prenylcyclo-l-tryptophyl-l-proline, tryprostatins, rhinocladins, and terezine D.
[Mh] Termos MeSH primário: Butadienos/química
Dipeptídeos/química
Hemiterpenos/química
Indóis/química
Compostos Organofosforados/química
Pentanos/química
Prolina/análogos & derivados
Prolina/química
Terpenos/química
[Mh] Termos MeSH secundário: Produtos Biológicos
Indóis/síntese química
Estrutura Molecular
Prenilação
Terpenos/síntese química
Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biological Products); 0 (Butadienes); 0 (Dipeptides); 0 (Hemiterpenes); 0 (Indoles); 0 (Organophosphorus Compounds); 0 (Pentanes); 0 (Terpenes); 0 (tryptophyl-proline); 059QF0KO0R (Water); 0A62964IBU (isoprene); 358-72-5 (3,3-dimethylallyl pyrophosphate); 9DLQ4CIU6V (Proline)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171003
[Lr] Data última revisão:
171003
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170815
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jnatprod.7b00464


  3 / 1337 MEDLINE  
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[PMID]:28605624
[Au] Autor:Grabowska-Polanowska B; Skowron M; Miarka P; Pietrzycka A; Sliwka I
[Ad] Endereço:Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland. Electronic address: beata.grabowska@ifj.edu.pl.
[Ti] Título:The application of chromatographic breath analysis in the search of volatile biomarkers of chronic kidney disease and coexisting type 2 diabetes mellitus.
[So] Source:J Chromatogr B Analyt Technol Biomed Life Sci;1060:103-110, 2017 Aug 15.
[Is] ISSN:1873-376X
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Chromatographic studies on breath composition are aimed at finding volatile markers useful for medical diagnostics or in screening investigations. Studies leading to the development of screening breath tests are especially important for the diagnostics of chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The aim of the presented study was to confirm diagnostic usefulness of chosen volatile compounds detected in breath, which are suggested as potential biomarkers of renal dysfunction and diabetes. Breath analysis were carried out in three groups: 10 healthy volunteers, 10 patients with CKD and 10 patients with CKD and T2DM. All exhaled air samples were analyzed using gas chromatograph (Agilent 6890GC) coupled with mass spectrometer (5975MSD). Thermal desorption was applied as the enrichment method. TMA was detected only in CKD patients. Higher breath concentrations of methanethiol (MeSH) were observed in CKD patients with coexisting diabetes than in patients with renal dysfunction only or in the healthy group. There was a tendency of increasing MeSH concentration in breath with increasing total glutathione in plasma (r=0.53, p=0.0026). Also, a trend of increasing dimethylsulfide (DMS) levels detected in breath was noticed with an increase of hydrogen sulfide concentration in plasma (r=0.74; p=0.00001) as well as with aspartate aminotransferase (AST), (r=0.61; p=0.001). The presented results suggest the possibility of applying TMA, MeSH, and DMS detection in breath as diagnostic methods.
[Mh] Termos MeSH primário: Biomarcadores/análise
Diabetes Mellitus Tipo 2/complicações
Diabetes Mellitus Tipo 2/metabolismo
Insuficiência Renal Crônica/complicações
Insuficiência Renal Crônica/metabolismo
Compostos Orgânicos Voláteis/análise
[Mh] Termos MeSH secundário: Acetona/análise
Adulto
Butadienos/análise
Estudos de Casos e Controles
Expiração
Feminino
Hemiterpenos/análise
Seres Humanos
Limite de Detecção
Masculino
Metilaminas/análise
Meia-Idade
Pentanos/análise
Reprodutibilidade dos Testes
Sulfetos/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 0 (Butadienes); 0 (Hemiterpenes); 0 (Methylamines); 0 (Pentanes); 0 (Sulfides); 0 (Volatile Organic Compounds); 0A62964IBU (isoprene); 1364PS73AF (Acetone); LHH7G8O305 (trimethylamine); QS3J7O7L3U (dimethyl sulfide)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170915
[Lr] Data última revisão:
170915
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170613
[St] Status:MEDLINE


  4 / 1337 MEDLINE  
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[PMID]:28416216
[Au] Autor:Pierini M; Carradori S; Menta S; Secci D; Cirilli R
[Ad] Endereço:Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma, P.le A. Moro 5, 00185 Rome, Italy.
[Ti] Título:3-(Phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole: A fascinating molecular framework to study the enantioseparation ability of the amylose (3,5-dimethylphenylcarbamate) chiral stationary phase. Part II. Solvophobic effects in enantiorecognition process.
[So] Source:J Chromatogr A;1499:140-148, 2017 May 26.
[Is] ISSN:1873-3778
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The enantiomers of five chiral compounds incorporating the 3-(phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole scaffold and differing only in the linear alkyl chain (varying in length from 1 to 5 carbon atoms) linked to the oxygen atom were directly separated on the amylose (3,5-dimethylphenylcarbamate) based Chiralpak AD-3 chiral stationary phase. The effects of the mobile phase composition, the structure of the analytes and temperature on the retention and enantioselectivity were investigated. It was found that the enantiomeric separations were in all cases enthalpy-driven and disfavored by entropic term. U-shape curves obtained by plotting the chromatographic data versus the alcoholic percentage in n-pentane-methanol and n-hexane-ethanol mobile phases highlighted that, at higher alcohol concentrations, solvophobic interactions were operative in the retention mechanism. The unusual trend of such curves was linked to the nature of alkyl chain of the pyrazolines and it was indicative of the solvophobic contribution to the achievement of a high degree of enantioseparation.
[Mh] Termos MeSH primário: Amilose/análogos & derivados
Cromatografia Líquida de Alta Pressão/instrumentação
Fenilcarbamatos/química
Pirazóis/química
[Mh] Termos MeSH secundário: Amilose/química
Cromatografia Líquida de Alta Pressão/métodos
Etanol/química
Hexanos/química
Pentanos/química
Estereoisomerismo
Temperatura Ambiente
Termodinâmica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (3,5-dimethylphenylcarbamate); 0 (Hexanes); 0 (Pentanes); 0 (Phenylcarbamates); 0 (Pyrazoles); 138361-09-8 (Chiralpak AD); 2DDG612ED8 (n-hexane); 3K9958V90M (Ethanol); 3QD5KJZ7ZJ (pyrazole); 4FEX897A91 (pentane); 9005-82-7 (Amylose)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171016
[Lr] Data última revisão:
171016
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170419
[St] Status:MEDLINE


  5 / 1337 MEDLINE  
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[PMID]:28367640
[Au] Autor:Li J; Wang XL; Wang AP; Xu SF; Jin HT
[Ad] Endereço:a State Key Laboratory of Bioactive Substance and Function of Natural Medicines , Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100050 , China.
[Ti] Título:Toxicokinetics and toxicity of potassium 2-(1-hydroxypentyl)-benzoate in beagle dogs.
[So] Source:J Asian Nat Prod Res;19(4):388-401, 2017 Apr.
[Is] ISSN:1477-2213
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB) is a prodrug of 3-n-butylphthalide (dl-NBP) for treatment of cerebral ischemic stroke in China, which undergoes lactonization to form dl-NBP in plasma. And, the phase II-III clinical trial of dl-PHPB has been approved by China Food and Drug Administration (CFDA) in 2013. In this study, a toxicity and toxicokinetics evaluation of dl-PHPB was performed using beagle dogs at specially high-dose 108 mg/kg/day (65-fold higher than humans at MHRD) for 4 weeks by intravenous administration, with a 3-week recovery period. And the plasma concentrations of dl-PHPB along with its metabolite dl-NBP were determined by HPLC-UV method. The results showed that dl-PHPB was quickly metabolized into dl-NBP, and no significant accumulation was observed. A slight to moderate behavior-associated toxicity was revealed in the process of delivery; and recovered to normal at the end of administration. Changes in the blood hematological profiles included significantly increased NEUT levels and lower LYM% content. Meanwhile, a notable increase in TG content was also observed in the serum biochemical parameters at 4-week post-exposure. These findings were reversible during the recovery period. The information from these studies would be taken into consideration for the interpretation of toxicology findings and provide a reference for clinical safety assessment.
[Mh] Termos MeSH primário: Benzoatos/farmacologia
Pentanos/farmacologia
Potássio/farmacologia
[Mh] Termos MeSH secundário: Animais
Benzofuranos/administração & dosagem
Benzofuranos/farmacologia
China
Cães
Feminino
Seres Humanos
Masculino
Estrutura Molecular
Toxicocinética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (2-(1-hydroxypentyl)-benzoate); 0 (Benzoates); 0 (Benzofurans); 0 (Pentanes); 822Q956KGM (3-n-butylphthalide); RWP5GA015D (Potassium)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170412
[Lr] Data última revisão:
170412
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE
[do] DOI:10.1080/10286020.2017.1302940


  6 / 1337 MEDLINE  
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[PMID]:28334669
[Au] Autor:Li JL; Zhang HH; Yang GP
[Ad] Endereço:Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education/Collaborative Innovation Center of Marine Science and Technology, Qingdao 266100, China.
[Ti] Título:Distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea during summer.
[So] Source:Chemosphere;178:291-300, 2017 Jul.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Spatial distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea in July 2013 were investigated. This study is the first to report the concentrations of isoprene in the China marginal seas. Isoprene concentrations in the surface seawater during summer ranged from 32.46 to 173.5 pM, with an average of 83.62 ± 29.22 pM. Distribution of isoprene in the study area was influenced by the diluted water from the Yangtze River, which stimulated higher in-situ phytoplankton production of isoprene rather than direct freshwater input. Variations in isoprene concentrations were found to be diurnal, with high values observed during daytime. A significant correlation was observed between isoprene and chlorophyll a in the study area. Relatively higher isoprene concentrations were recorded at stations where the phytoplankton biomass was dominated by Chaetoceros, Skeletonema, Pennate-nitzschia, and Thalassiosira. Positive correlation was observed between isoprene and methyl iodide. In addition, sea-to-air fluxes of isoprene approximately ranged from 22.17 nmol m d -537.2 nmol m d , with an average of 161.5 ± 133.3 nmol m d . These results indicate that the coastal and shelf areas may be important sources of atmospheric isoprene.
[Mh] Termos MeSH primário: Poluentes Atmosféricos/química
Butadienos/análise
Hemiterpenos/análise
Pentanos/análise
Água do Mar/química
Poluentes Químicos da Água/química
[Mh] Termos MeSH secundário: Biomassa
China
Clorofila/análise
Fitoplâncton/metabolismo
Rios
Estações do Ano
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Air Pollutants); 0 (Butadienes); 0 (Hemiterpenes); 0 (Pentanes); 0 (Water Pollutants, Chemical); 0A62964IBU (isoprene); 1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170601
[Lr] Data última revisão:
170601
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170324
[St] Status:MEDLINE


  7 / 1337 MEDLINE  
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[PMID]:28277620
[Au] Autor:Brentzel ZJ; Barnett KJ; Huang K; Maravelias CT; Dumesic JA; Huber GW
[Ad] Endereço:Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
[Ti] Título:Chemicals from Biomass: Combining Ring-Opening Tautomerization and Hydrogenation Reactions to Produce 1,5-Pentanediol from Furfural.
[So] Source:ChemSusChem;10(7):1351-1355, 2017 Apr 10.
[Is] ISSN:1864-564X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:A process for the synthesis of 1,5-pentanediol (1,5-PD) with 84 % yield from furfural is developed, utilizing dehydration/hydration, ring-opening tautomerization, and hydrogenation reactions. Although this process has more reaction steps than the traditional direct hydrogenolysis of tetrahydrofurfuryl alcohol (THFA), techno-economic analyses demonstrate that this process is the economically preferred route for the synthesis of biorenewable 1,5-PD. 2-Hydroxytetrahydropyran (2-HY-THP) is the key reaction pathway intermediate that allows for a decrease in the minimum selling price of 1,5-PD. The reactivity of 2-HY-THP is 80 times greater than that of THFA over a bimetallic hydrogenolysis catalyst. This enhanced reactivity is a result of the ring-opening tautomerization to 5-hydoxyvaleraldehyde and subsequent hydrogenation to 1,5-PD.
[Mh] Termos MeSH primário: Biomassa
Furaldeído/química
Glicóis/química
Pentanos/química
[Mh] Termos MeSH secundário: Hidrogenação
Isomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glycols); 0 (Pentanes); 07UXZ0SCST (1,5-pentanediol); DJ1HGI319P (Furaldehyde)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170606
[Lr] Data última revisão:
170606
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE
[do] DOI:10.1002/cssc.201700178


  8 / 1337 MEDLINE  
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[PMID]:28256295
[Au] Autor:Srivastva N; Vishwakarma P; Bhardwaj Y; Singh A; Manjunath K; Dubey SK
[Ad] Endereço:Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
[Ti] Título:Kinetic and molecular analyses reveal isoprene degradation potential of Methylobacterium sp.
[So] Source:Bioresour Technol;242:87-91, 2017 Oct.
[Is] ISSN:1873-2976
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Efforts were made to isolate and characterize bacteria capable of growing on methane and organic compounds, and to achieve the simultaneous degradation of more than one pollutant. Among the methanotrophs, species of Methylobacterium was able to catabolize a variety of hydrocarbons, including the branched-chain alkenes. Therefore, laboratory incubations experiments were carried out in batch mode to assess the potential of Methylobacterium sp. PV1 for degrading isoprene, the low-molecular-weight alkene, the most abundant non-methane volatile hydrocarbon present in the environment. Methylobacterium sp. PV1, isolated from paddy field soil, was characterized by pmoA and 16S rRNA gene sequencing and FAME analysis, and used for isoprene degradation. The kinetics of biodegradation is studied using the Michaelis-Menten model. The optimum degradation (80%) with maximum average relative degradation rate was observed at 150ppm isoprene. The degradation products were also analyzed using FTIR.
[Mh] Termos MeSH primário: Butadienos/metabolismo
Hemiterpenos/metabolismo
Methylobacterium
Pentanos/metabolismo
[Mh] Termos MeSH secundário: Biodegradação Ambiental
Filogenia
RNA Ribossômico 16S
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Butadienes); 0 (Hemiterpenes); 0 (Pentanes); 0 (RNA, Ribosomal, 16S); 0A62964IBU (isoprene)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170304
[St] Status:MEDLINE


  9 / 1337 MEDLINE  
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[PMID]:28173926
[Au] Autor:Nikolaeva OA; Patrushev YV; Sidelnikov VN
[Ad] Endereço:Boreskov Institute of Catalysis, pr. Lavrentieva 5, Novosibirsk, 630090, Russia; Novosibirsk State University, Pirogova Str., 2, Novosibirsk, 630090, Russia.
[Ti] Título:Chromatographic properties PLOT multicapillary columns.
[So] Source:J Chromatogr A;1488:126-133, 2017 Mar 10.
[Is] ISSN:1873-3778
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Multicapillary columns (MCCs) for gas chromatography make it possible to perform high-speed analysis of the mixtures of gaseous and volatile substances at a relatively large amount of the loaded sample. The study was performed using PLOT MCCs for gas-solid chromatography (GSC) with different stationary phases (SP) based on alumina, silica and poly-(1-trimethylsilyl-1-propyne) (PTMSP) polymer as well as porous polymers divinylbenzene-styrene (DVB-St), divinylbenzene-vinylimidazole (DVB-VIm) and divinylbenzene-ethylene glycol dimethacrylate (DVB-EGD). These MCCs have the efficiency of 4000-10000 theoretical plates per meter (TP/m) and at a column length of 25-30cm can separate within 10-20s multicomponent mixtures of substances belonging to different classes of chemical compounds. The sample amount not overloading the column is 0.03-1µg and depends on the features of a porous layer. Examples of separations on some of the studied columns are considered.
[Mh] Termos MeSH primário: Cromatografia Gasosa/métodos
[Mh] Termos MeSH secundário: Adsorção
Hidrocarbonetos Halogenados/análise
Metacrilatos/química
Microscopia Eletrônica de Varredura
Pentanos/química
Poliestirenos/química
Porosidade
Reologia
Dióxido de Silício/química
Compostos de Vinila/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Hydrocarbons, Halogenated); 0 (Methacrylates); 0 (Pentanes); 0 (Polystyrenes); 0 (Vinyl Compounds); 4FEX897A91 (pentane); 7631-86-9 (Silicon Dioxide); 7BK5G69305 (ethylene dimethacrylate); IZ715T4SBU (divinyl benzene)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170417
[Lr] Data última revisão:
170417
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170209
[St] Status:MEDLINE


  10 / 1337 MEDLINE  
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[PMID]:28139350
[Au] Autor:Kudoh K; Hotta S; Sekine M; Fujii R; Uchida A; Kubota G; Kawano Y; Ihara M
[Ad] Endereço:Department of Bioscience and Food Production Science, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 8304 Minamiminowa, Nagano 399-4511, Japan.
[Ti] Título:Overexpression of endogenous 1-deoxy-d-xylulose 5-phosphate synthase (DXS) in cyanobacterium Synechocystis sp. PCC6803 accelerates protein aggregation.
[So] Source:J Biosci Bioeng;123(5):590-596, 2017 May.
[Is] ISSN:1347-4421
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:1-Deoxy-d-xylulose 5-phosphate synthase (DXS) is a rate-limiting enzyme in the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway, which is responsible for the production of precursors of all isoprenoids. In a previous study, we had examined the overexpression of an endogenous DXS in a Synechocystis sp. PCC6803 mutant (DXS_ox), and found that the dxs mRNA level was 4-fold higher than that in the wild-type (WT) strain. However, the DXS protein level was only 1.5-fold higher, leading to the assumption that the level might be regulated by post-transcriptional events. In this study, we have additionally introduced an exogenous isoprene synthase (IspS; which can release MEP pathway products from the cell as gaseous isoprene) into the WT and DXS_ox strains (WT-isP and DXSox-isP strains, respectively), and their detailed DXS expression profiles were investigated from the induction phase through to the late-logarithmic phase. In the induction phase, the isoprene productivity of the DXSox-isP strain was slightly but significantly (1.4- to 1.8-fold) higher than that of the WT-isP strain, whereas the levels were comparable in the other phases. Interestingly, the ratios of soluble:insoluble DXS protein were remarkably low in the DXSox-isP strain during the induction phase to the early-logarithmic phase, resulting in a moderate level of soluble DXS. All our results suggested that the high translation rate of DXS disturbs the refolding process of DXS. To enhance the concentration of the active DXS in cyanobacteria, the enhancement of the DXS maturation system or the introduction of exogenous and robust DXS proteins might be necessary.
[Mh] Termos MeSH primário: Agregados Proteicos
Synechocystis/genética
Synechocystis/metabolismo
Transferases/genética
Transferases/metabolismo
[Mh] Termos MeSH secundário: Alquil e Aril Transferases/biossíntese
Alquil e Aril Transferases/genética
Alquil e Aril Transferases/metabolismo
Butadienos
Eritritol/análogos & derivados
Eritritol/metabolismo
Gases/metabolismo
Hemiterpenos/biossíntese
Engenharia Metabólica
Pentanos
Pentosefosfatos/biossíntese
RNA Mensageiro/análise
Solubilidade
Fosfatos Açúcares/metabolismo
Terpenos/metabolismo
Transferases/biossíntese
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (1-deoxylulose 5-phosphate); 0 (2-C-methylerythritol 4-phosphate); 0 (Butadienes); 0 (Gases); 0 (Hemiterpenes); 0 (Pentanes); 0 (Pentosephosphates); 0 (Protein Aggregates); 0 (RNA, Messenger); 0 (Sugar Phosphates); 0 (Terpenes); 0A62964IBU (isoprene); EC 2.- (Transferases); EC 2.2.1.- (deoxyxylulose-5-phosphate synthase); EC 2.5.- (Alkyl and Aryl Transferases); EC 2.5.1.- (isoprene synthase); RA96B954X6 (Erythritol)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170509
[Lr] Data última revisão:
170509
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170201
[St] Status:MEDLINE



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