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Id: biblio-1022610
Autor: Xiao, Qiong; Zhu, Yanbing; Li, Jiajia; Wu, Changzheng; Ni, Hui; Xiao, Anfeng.
Título: Fermentation optimization and enzyme characterization of a new ι-Carrageenase from Pseudoalteromonas carrageenovora ASY5
Fonte: Electron. j. biotechnol;32:26-34, Mar. 2018. graf, tab.
Idioma: en.
Projeto: University-Enterprise Cooperation of Fujian Province; . Public Science and Technology Research Funds Projects of Ocean; . Major Science and Technology Programs and Special Topics of Fujian Province; . Key Program of Science Foundation of Fujian Province.
Resumo: Background: A new ι-carrageenase-producing strain was screened from mangroves and authenticated as Pseudoalteromonas carrageenovora ASY5 in our laboratory. The potential application of this new strain was evaluated. Results: Medium compositions and culturing conditions in shaking flask fermentation were firstly optimized by single-factor experiment. ι-Carrageenase activity increased from 0.34 U/mL to 1.08 U/mL after test optimization. Optimal fermentation conditions were 20°C, pH 7.0, incubation time of 40 h, 15 g/L NaCl, 1.5% (w/v) yeast extract as nitrogen source, and 0.9% (w/v) ι-carrageenan as carbon source. Then, the crude ι-carrageenase was characterized. The optimum temperature and pH of the ι-carrageenase were 40°C and 8.0, respectively. The enzymatic activity at 35­40°C for 45 min retained more than 40% of the maximum activity. Meanwhile, The ι-carrageenase was inhibited by the addition of 1 mmol/L Cd2+ and Fe3+ but increased by the addition of 1 mmol/L Ag+, Ba2+, Ca2+, Co2+, Mn2+, Zn2+, Fe2+, and Al3+. The structure of oligosaccharides derived from ι-carrageenan was detected using electrospray ionization mass spectrometry (ESI-MS). The ι-carrageenase degraded ι-carrageenan, yielding disaccharides and tetrasaccharides as main products. Conclusions: The discovery and study of new ι-carrageenases are beneficial not only for the production of ι-carrageenan oligosaccharides but also for the further utilization in industrial production.
Descritores: Proteínas de Bactérias/metabolismo
Pseudoalteromonas/enzimologia
Glicosídeo Hidrolases/metabolismo
-Oligossacarídeos/biossíntese
Temperatura Ambiente
Carbono/metabolismo
Carragenina/biossíntese
Espectrometria de Massas por Ionização por Electrospray
Fermentação
Concentração de Íons de Hidrogênio
Hidrólise
Nitrogênio/metabolismo
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1017249
Autor: Li, Tao; Ding, Yatong; Zhang, Jun; Jiao, Guobao; Sun, Lipeng; Liu, Zhongmin; Qiu, Liyou.
Título: Improving the expression of recombinant pullulanase by increasing mRNA stability in Escherichia coli
Fonte: Electron. j. biotechnol;29:63-67, sept. 2017. ilus, tab, graf.
Idioma: en.
Projeto: National Science and Technology Program in Rural Areas during the 12th Five-Year Plan period.
Resumo: Background: Pullulanase production in both wild-type strains and recombinantly engineered strains remains low. The Shine-Dalgarno (SD) sequence and stem-loop structure in the 5' or 3' untranslated region (UTR) are well-known determinants of mRNA stability. This study investigated the effect of mRNA stability on pullulanase heterologous expression. Results: We constructed four DNA fragments, pulA, SD-pulA, pulA-3t, and SD-pulA-3t, which were cloned into the expression vector pHT43 to generate four pullulanase expression plasmids. The DNA fragment pulA was the coding sequence (CDS) of pulA in Klebsiella variicola Z-13. SD-pulA was constructed by the addition of the 5' SD sequence at the 5' UTR of pulA. pulA-3t was constructed by the addition of a 3' stem-loop structure at the 3' UTR of pulA. SD-pulA-3t was constructed by the addition of the 5' SD sequence at the 5' UTR and a 3' stem-loop structure at the 3' UTR of pulA. The four vectors were transformed into Escherichia coli BL21(DE3). The pulA mRNA transcription of the transformant harboring pHT43-SD-pulA-3t was 338.6%, 34.9%, and 79.9% higher than that of the other three transformants, whereas the fermentation enzyme activities in culture broth and intracellularly were 107.0 and 584.1 times, 1.2 and 2.0 times, and 62.0 and 531.5 times the amount of the other three transformants (pulA, SD-pulA, and pulA-3 t), respectively. Conclusion: The addition of the 5' SD sequence at the 5' UTR and a 3' stem-loop structure at the 3' UTR of the pulA gene is an effective approach to increase pulA gene expression and fermentation enzyme activity.
Descritores: Escherichia coli/enzimologia
Escherichia coli/genética
Glicosídeo Hidrolases/metabolismo
-Transformação Genética
Expressão Gênica
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Estabilidade de RNA
Fermentação
Vetores Genéticos
Glicosídeo Hidrolases/genética
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1009650
Autor: Niu, Dandan; Qiao, Jian; Li, Pujun; Tian, Kangming; Liu, Xiaoguang; Singh, Suren; Lu, Fuping.
Título: Highly efficient enzymatic preparation of isomalto-oligosaccharides from starch using an enzyme cocktail
Fonte: Electron. j. biotechnol;26:46-51, Mar. 2017. graf, tab.
Idioma: en.
Projeto: Tianjin Research Program of Application Foundation and Advanced Technology; . Science and Technology Development Foundation of Fujian Higher Education; . Priming Scientific Research Foundation of Fuzhou University; . Science and Technology Development Foundation of Tianjin Higher Education; . National Natural Science Foundation of China.
Resumo: Background: Current commercial production of isomalto-oligosaccharides (IMOs) commonly involves a lengthy multistage process with low yields. Results: To improve the process efficiency for production of IMOs, we developed a simple and efficient method by using enzyme cocktails composed of the recombinant Bacillus naganoensis pullulanase produced by Bacillus licheniformis, α-amylase from Bacillus amyloliquefaciens, barley bran ß-amylase, and α-transglucosidase from Aspergillus niger to perform simultaneous saccharification and transglycosylation to process the liquefied starch. After 13 h of reacting time, 49.09% IMOs (calculated from the total amount of isomaltose, isomaltotriose, and panose) were produced. Conclusions: Our method of using an enzyme cocktail for the efficient production of IMOs offers an attractive alternative to the process presently in use.
Descritores: Oligossacarídeos/metabolismo
Amido/metabolismo
Enzimas/metabolismo
Isomaltose/metabolismo
-Oligossacarídeos/biossíntese
Aspergillus niger/enzimologia
Temperatura Ambiente
Bacillus/enzimologia
beta-Amilase/metabolismo
Glicosilação
Liquefação
alfa-Amilases/metabolismo
Fermentação
Glucosidases/metabolismo
Glicosídeo Hidrolases/metabolismo
Concentração de Íons de Hidrogênio
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1008291
Autor: Xiao, Anfeng; Xiao, Qiong; Lin, Yan; Ni, Hui; Zhu, Yanbing; Cai, Huinong.
Título: Efficient immobilization of agarase using carboxyl-functionalized magnetic nanoparticles as support
Fonte: Electron. j. biotechnol;25:13-20, ene. 2017. ilus, graf.
Idioma: en.
Projeto: University-Enterprise Cooperation of Fujian Province University; . Major Science and Technology Programs and Special Topics of Fujian Province.
Resumo: Background: A simple and efficient strategy for agarase immobilization was developed with carboxyl-functionalized magnetic nanoparticles (CMNPs) as support. The CMNPs and immobilized agarase (agarase-CMNPs) were characterized by transmission electron microscopy, dynamic light scattering, vibrating sample magnetometry, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and zeta-potential analysis. The hydrolyzed products were separated and detected by ESI-TOF-MS. Results: The agarase-CMNPs exhibited a regular spherical shape with a mean diameter of 12 nm, whereas their average size in the aqueous solution was 43.7 nm as measured by dynamic light scattering. These results indicated that agarase-CMNPs had water swelling properties. Saturation magnetizations were 44 and 29 emu/g for the carriers and agarase-CMNPs, respectively. Thus, the particles had superparamagnetic characteristics, and agarase was successfully immobilized onto the supports. Agaro-oligosaccharides were prepared with agar as substrate using agarase-CMNPs as biocatalyst. The catalytic activity of agarase-CMNPs was unchanged after six reuses. The ESI-TOF mass spectrogram showed that the major products hydrolyzed by agarase-CMNPs after six recycle uses were neoagarotetraose, neoagarohexaose, and neoagarooctaose. Meanwhile, the end-products after 90 min of enzymatic treatment by agarase-CMNPs were neoagarobiose and neoagarotetraose. Conclusions: The enhanced agarase properties upon immobilization suggested that CMNPs can be effective carriers for agarase immobilization. Agarase-CMNPs can be remarkably used in developing systems for repeated batch production of agar-derived oligosaccharides.
Descritores: Oligossacarídeos/metabolismo
Enzimas Imobilizadas
Nanopartículas de Magnetita/química
Glicosídeo Hidrolases/metabolismo
-Termogravimetria
Difração de Raios X
Estabilidade Enzimática
Catálise
Microscopia Eletrônica de Transmissão
Magnetometria
Difusão Dinâmica da Luz
Glicosídeo Hidrolases/química
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-967017
Autor: Khalili, Elham; Huyop, Fahrul; Javed, Muhammad Arshad; Mahat, Naji Arafat; Batumalaie, Kalaivani; Wahab, Roswanira Abdul.
Título: Assessments on the catalytic and kinetic properties of beta-glucosidase isolated from a highly efficient antagonistic fungus Trichoderma harzianum / Avaliações das propriedades catalíticas e cinéticas da beta-glucosidase isoladas de um fungo antagonísta altamente eficiente Trichoderma harzianum
Fonte: Biosci. j. (Online);34(4):830-847, july/aug. 2018. tab, ilus, graf.
Idioma: en.
Resumo: Due to the toxicity and inefficiency of chemical fungicides to control infestation of Macrophomina phaseolina (Tassi) Goid which causes charcoal rot in plants, a biotechnological approach using - glucosidase (EC.3.2.1) as the alternative bioactive ingredient in fungicide is hereby, proposed. The extracellular enzyme was isolated from a highly efficient fungal antagonist, Trichoderma harzianum T12. The highly similar molecular masses obtained using SDS-PAGE (96 kDa) and MALDI-TOF mass spectrometry (98.3 kDa) affirmed that the -glucosidase was purified to homogeneity. Consequently, optimum catalytic parameters that rendered the highest enzyme activity were found to be: 45°C, pH 7, inoculum size of 10 % (w/v), supplementation with metal ions Zn2+ and Mn2+ ions, and Tween 80. Addition of wheat bran and (NH4)2SO4 as carbon and nitrogen sources also improved enzyme activity. BLASTn showed the sequence of -glucosidase T12 was highly identical to other -glucosidases viz. T. harzianum strain IOC-3844 (99%), T. gamsii and T. virens bgl1 (86 %) as well as T. reesei strain SJVTR and T. viride strain AS 3.3711 (84 %). Kinetic assessment showed that -glucosidase T12 catalyzes hydrolytic activity is characterized by a Km of 0.79 mM and Vmax of 8.45 mM min-1 mg-1 protein, with a corresponding kcat of 10.69 s-1.

Devido à toxicidade e ineficiência dos fungicidas químicos para controlar a infestação de Macrophomina phaseolina (Tassi) Goid que causa o apodrecimento das plantas, uma abordagem biotecnológica usando - glicosidase (EC.3.2.1) como o ingrediente bioativo alternativo do fungicida é por este meio, proposto. A enzima extracelular foi isolada de um antagonista fúngico altamente eficiente, o Trichoderma harzianum T12. As massas moleculares altamente similares obtidas usando SDS-PAGE (96 kDa) e espectrometria de massa MALDI-TOF (98,3 kDa) afirmaram que a -glicosidase foi purificada até a homogeneidade. Consequentemente, os parâmetros catalíticos ótimos que apresentaram a maior atividade enzimática foram: 45°C, pH 7, tamanho do inóculo de 10% (p / v), suplementação com íons de metais Zn2+ e Mn2+, e Tween 80. Adição de farelo de trigo e (NH4) 2SO4 como fontes de carbono e nitrogênio também melhoraram a atividade enzimática. O BLASTn mostrou que a sequência da -glicosidase T12 era altamente idêntica a outras -glicosidase viz. A estirpe T. harzianum IOC-3844 (99%), T. gamsii e T. virens bgl1 (86%) assim como a estirpe T. reesei SJVTR e a estirpe T. viride AS 3.3711 (84%). A avaliação cinética mostrou que -glicosidase T12 catalisa a actividade hidrolítica caracterizada por um Km de 0,79 mM e Vmax de 8,45 mM min-1 mg-1 de proteína, com um correspondente kcat de 10,69 s-1.
Descritores: Trichoderma
Cinética
Fungos
Fungicidas Industriais
Glicosídeo Hidrolases
-Biotecnologia
Responsável: BR396.1 - Biblioteca Central


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Id: biblio-889174
Autor: Melo, Ricardo Rodrigues de; Persinoti, Gabriela Felix; Paixão, Douglas Antonio Alvaredo; Squina, Fábio Márcio; Ruller, Roberto; Sato, Helia Harumi.
Título: Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil
Fonte: Braz. j. microbiol;48(4):612-614, Oct.-Dec. 2017. tab.
Idioma: en.
Resumo: ABSTRACT Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp. strain F1 has 69 contigs with a total genome size of 8,142,296 bp and G + C 72.65%. Preliminary genome analysis identified 175 proteins as Carbohydrate-Active Enzymes, being 85 glycoside hydrolases organized in 33 distinct families. This draft genome information provides new insights on the key genes encoding hydrolytic enzymes involved in biomass deconstruction employed by soil bacteria.
Descritores: Proteínas de Bactérias/genética
Genoma Bacteriano
Glicosídeo Hidrolases/genética
Microbiologia do Solo
Streptomyces/enzimologia
Streptomyces/isolamento & purificação
-Proteínas de Bactérias/metabolismo
Composição de Bases
Brasil
Glicosídeo Hidrolases/metabolismo
Família Multigênica
Filogenia
Streptomyces/classificação
Streptomyces/genética
Responsável: BR1.1 - BIREME


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Id: biblio-889130
Autor: Dinarvand, Mojdeh; Rezaee, Malahat; Foroughi, Majid.
Título: Optimizing culture conditions for production of intra and extracellular inulinase and invertase from Aspergillus niger ATCC 20611 by response surface methodology (RSM)
Fonte: Braz. j. microbiol;48(3):427-441, July-Sept. 2017. tab, graf.
Idioma: en.
Resumo: Abstract The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R2) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30 °C, 6% (v/v), inoculum size and 150 rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications.
Descritores: Aspergillus niger/metabolismo
beta-Frutofuranosidase/biossíntese
Glicosídeo Hidrolases/biossíntese
Microbiologia Industrial/métodos
-Aspergillus niger/enzimologia
Aspergillus niger/genética
Aspergillus niger/crescimento & desenvolvimento
beta-Frutofuranosidase/genética
Reatores Biológicos/microbiologia
Meios de Cultura/química
Meios de Cultura/metabolismo
Fermentação
Glicosídeo Hidrolases/genética
Temperatura Ambiente
Tipo de Publ: Estudos de Avaliação
Responsável: BR1.1 - BIREME


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Id: biblio-833334
Autor: Peru. Ministerio de Salud. Seguro Integral de Salud.
Título: Informe de evaluación rápida de tecnología sobre seguridad y efectividad de laronidasa para mucopolisacaridosis tipo I / Rapid evaluation report of technology on safety and effectiveness of laronidase for mucopolysaccharidosis type I.
Fonte: s.l; s.n; 2015. fig, tab.
Idioma: es.
Resumo: La MPS I es una enfermedad pan-étnica con una incidencia estimada en 1:100 000 nacidos vivos. Aproximadamente, 50% a 80% de los pacientes presenta el fenotipo grave de la enfermedad (o Síndrome de Hurler). Un estudio poblacional mostró que el fenotipo atenuado representa 26% de la población total de pacientes con MPS I. Sin embargo, esos datos pueden estar subestimados, una vez que el diagnóstico de casos graves parece ser más fácil que el de casos atenuados. Según el MPS I Registry (patrocinado por la Genzyme Corporation), hasta el 2009 existían 845 pacientes con MPS I identificados en todo el mundo. (2) De ellos 118 fueron de cinco países de Latinoamérica (60% Brasil, 14% Argentina, 17% México, 3% Chile, y 5% Colombia). El resto del mundo (ROW, por sus siglas en inglés) tenía 727 pacientes distribuidos en 27 países: 56% Europa, 41% América del Norte y 3% de Asia Pacífico. Al respecto de la distribución de fenotipos del total de latinoamericanos reportados, el 31% reportaron tener Síndrome de Hurler; mientras que el resto del mundo mostró un 62%. Sin embargo hubo una gran proporción de pacientes en Latinoamérica sin determinar o reportar fenotipo (22 frente 6% del resto del mundo). De acuerdo a la revisión de la literatura, se tienen estos datos de incidencia y de supervivencia de acuerdo al fenotipo de MPS I. Como resultado de la utilización de laronidasa en pacientes con mucopolisacaridosis tipo I se observó mejoras en el porcentaje de capacidad vital forzada, hepato/esplenomegalia, excreción urinaria de los GAG, índice de apnea/hipoapnea del sueño (IAH), amplitud de flexión de la espalda, agudeza visual, índice de discapacidad CHAQ/HAQ, test de Marcha de los 6 Minutos (TM6M). Se recomienda cubrir con generación de evidencia.(AU)
Descritores: Glicosídeo Hidrolases/administração & dosagem
Glicosídeo Hidrolases/uso terapêutico
Mucopolissacaridose I/tratamento farmacológico
Mucopolissacaridose I/terapia
-Avaliação da Tecnologia Biomédica
Resultado do Tratamento
Tipo de Publ: Revisão
Relatório Técnico
Estudos de Avaliação
Responsável: BR1.1 - BIREME


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Id: lil-778412
Autor: Rubab, Kaniz; Abbasi, Muhammad Athar; Aziz-ur-Rehman; Siddiqui, Sabahat Zahra; Ashraf, Muhammad; Shaukat, Ayesha; Ahmad, Irshad; Lodhi, Muhammad Arif; Khan, Farman Ali; Shahid, Muhammad; Akhtar, Muhammad Nadeem.
Título: Convergent synthesis of new N -substituted 2-{[5-(1H -indol-3-ylmethyl)-1, 3, 4-oxadiazol-2-yl]sulfanyl}acetamides as suitable therapeutic agents
Fonte: Braz. j. pharm. sci;51(4):931-947, Oct.-Dec. 2015. tab, graf.
Idioma: en.
Resumo: abstract A series of N-substituted 2-{[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetamides (8a-w) was synthesized in three steps. The first step involved the sequential conversion of 2-(1H-indol-3-yl)acetic acid (1) to ester (2) followed by hydrazide (3) formation and finally cyclization in the presence of CS2 and alcoholic KOH yielded 5-(1H-indole-3-yl-methyl)-1,3,4-oxadiazole-2-thiol (4). In the second step, aryl/aralkyl amines (5a-w) were reacted with 2-bromoacetyl bromide (6) in basic medium to yield 2-bromo-N-substituted acetamides (7a-w). In the third step, these electrophiles (7a-w) were reacted with 4 to afford the target compounds (8a-w). Structural elucidation of all the synthesized derivatives was done by 1H-NMR, IR and EI-MS spectral techniques. Moreover, they were screened for antibacterial and hemolytic activity. Enzyme inhibition activity was well supported by molecular docking results, for example, compound 8q exhibited better inhibitory potential against α-glucosidase, while 8g and 8b exhibited comparatively better inhibition against butyrylcholinesterase and lipoxygenase, respectively. Similarly, compounds 8b and 8c showed very good antibacterial activity against Salmonella typhi, which was very close to that of ciprofloxacin, a standard antibiotic used in this study. 8c and 8l also showed very good antibacterial activity against Staphylococcus aureus as well. Almost all compounds showed very slight hemolytic activity, where 8p exhibited the least. Therefore, the molecules synthesized may have utility as suitable therapeutic agents.

resumo Uma série de acetamidas 2-{[5-(1H-indol-3-ilmetil)-1,3,4-oxadiazol-2-il]sulfanila} N-substituídas (8a-w) foi sintetizada em três fases. A primeira etapa envolveu a conversão sequencial de ácido 2-(1H-indol-3-il)acético (1) a éster (2), seguido por hidrazida (3) e, finalmente, a e ciclização na presença de CS2 e KOH alcoólico produziu 5-(1H-indol-3-il- metil)-1,3,4-oxadiazole-2-tiol (4). Na segunda etapa, aminas arílicas/aralquílicas(5a-w) reagiram com brometo de 2-bromoacetila (6​​), em meio básico, para se obter acetamidas 2-bromo-N-substituídas (7a-w). Na terceira etapa, estes eletrófilos (7a- w) reagiram com 4, para se obter os compostos alvo (8a-w). A elucidação estrutural de todos os derivados sintetizados foi realizada por 1H-NMR, IR e técnicas de espectrometria de EI-MS. Além disso, eles foram submetidos a triagem de atividade antibacteriana e hemolítica. Análise da inibição enzimática foi bem apoiada pelos resultados de docking molecular. Por exemplo, o composto 8q exibiu melhor potencial inibitório contra α-glicosidase, e os compostos 8g e 8b exibiram, comparativamente, melhor inibição contra butirilcolinesterase (BChE) elipoxigenase (LOX), respectivamente. Do mesmo modo os compostos 8b e 8c mostraram excelente potencial antibacteriano contra SalmonellaTyphi, semelhante ao do ciprofloxacino, antibiótico padrão usado neste estudo. Os compostos 8c e 8l também mostraram excelente potencial antibacteriano contra Staphylococcus aureus . Quase todos os compostos mostraram pequena atividade hemolítica, sendo que o composto 8p apresentou menor atividade. Assim, as moléculas sintetizadas podem ter a sua utilidade como agentes terapêuticos adequados.
Descritores: Acetamidas/análise
Ácido Hidroxi-Indolacético/análise
-Butirilcolinesterase/análise
Ensaio de Atividade Hemolítica de Complemento/classificação
Glicosídeo Hidrolases/farmacocinética
Lipoxigenases/farmacocinética
Responsável: BR1.1 - BIREME


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Id: lil-774265
Autor: Carvalho, Paulo Vinícius Sanches Daltro de.
Título: Modelagem molecular de novos derivados triazólicos inibidores de glicosidases com potencial terapêutico em diabetes do tipo 2 / Molecular modeling of new triazole derivatives with therapeutic potential of glycosidases inhibitors in type 2 diabetes.
Fonte: Rio de Janeiro; s.n; 2014. xvii,103 p. ilus, tab, graf.
Idioma: pt.
Tese: Apresentada a Instituto Oswaldo Cruz para obtenção do grau de Mestre.
Resumo: Números recentes de casos de Diabetes tipo 2 revelam a urgência parao desenvolvimento de novos fármacos para o tratamento desta patologia.Nosso grupo sintetizou compostos triazólicos glicoconjugados (TGCs) com atividade inibitória 20X maior do que a acarbose (um anti-hiperglicemiante,inibidor de α-glicosidase e alfa-amilase pancreática, em uso clínico) contra MAL12 de levedura (Saccharomyces cerevisiae maltase). Estudos sobre o mecanismo cinético de inibição destes compostos mostraram que todos os inibidores apresentam mecanismo de inibição do tipo mista tanto em maltase de levedura quanto em α-amilase pancreática suína. Baseando-se em dados cinéticos, um mecanismo de inibição estrutural, para ambas enzimas por TGCs, foi considerado como hipótese por nosso grupo. Esstes compostos estariam ligados nos subsítios +2 e +3, adjacentes ao substrato (p-nitrofenil-α-D- glicopiranosideo - pNPG para MAL12 e 2-cloro-4-nitrofenil-α-Dmaltotriosídeo- CNPG3 no caso de AAPs). Dada a ausência de dados experimentais no aspecto estrutural do processo de inibição dos TGCs, nós realizamos uma análise comparativa da topologia sítio ativo das três enzimas pertencentes à família GH13: MAL12, α-amilase pancreático humano (AAPH) eAAPS. De acordo com os resultados de inibição do tipo mista, nós usamos asenzimas livres (E) e o complexo enzima-substrato (ES) como receptores emsimulações de docking dos ligantes TGC, usando o protocolo induced fitdocking (IFD) (Schrõdinger, LLC). Os resultados obtidos corroboram a hipótese levantada pelo nosso grupo, na qual os compostos TGC estariam ligados em subsítios adjacentes ao do substrato. E, também, ressalta-se a inversão das subunidades de alguns ligantes ao estarem ancorados ao sítio ativo de APP eo deslocamento dos ligantes GPESBs para o centro catalítico das enzimas, oque comporta uma característica de mecanismo de inibição do tipo mista...

Recent numbers of cases of Type II diabetes demonstrate the urgency todevelop new drugs for the treatment of this pathology. Our group hassynthesized glycoconjugate triazole compounds (GTCs) with 20X greaterinhibitory activity than acarbose (a hypoglycemiant alpha-glucosidase andpancreatic α-amylase inhibitor in clinical use) against yeast MAL12(Saccharomyces cerevisiae maltase). Studies on the kinetic mechanism ofinhibition of these compounds showed that all inhibitors act non-competitivelyboth on yeast maltase and porcine (Sus scrofa) pancreatic α-amylase (PPA).Based on kinetic data, the structural mechanism of inhibition against bothenzymes by GTCs has been hypothesized by our group where thesecompounds can be bound in the +2 and +3 subsites, adjacent to the substrate(4-nitrophenyl-α-D-maltoglucoside - pNPG for Mal12 and 2-chloro-4-nitrophenyl-α-D-maltotrioside - CNPG3 in the case of PPA). Since there is a lack ofexperimental data on the structural aspects of the inhibition process of theGTCs, we performed a comparative analysis of the active site topology of threeenzymes belonging to GH13 family: MAL12, PPA and human pancreatic α-amylase (HPA). In accordance with the results of non-competitive inhibition, weused both free enzyme (E) and enzyme - substrate (ES) complexes asreceptors in docking simulations of the GTC ligands using the induced-fitdocking (IFD) protocol (Schrõdinger, LLC). The obtained results corroboratewith our hypothesis, which suggests that TGC compounds bind to adjacentsubsites of substrate. In addition, the inversion of subunits of some ligandshighlights when they are anchored to the active site of PPA and thedisplacement of GBESB ligands to the enzyme catalytic center. Thischaracteristic reveals an inhibition mechanism of mixed type...
Descritores: DIABETES MELLITUS TIPO TEMEFOS
Glicosídeo Hidrolases/classificação
Glicosídeo Hidrolases/química
Triazóis
-Modelos Anatômicos
Limites: Seres Humanos
Responsável: BR15.1 - Biblioteca de Ciências Biomédicas



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