Base de dados : LILACS
Pesquisa : D01.248.497.300.333 [Categoria DeCS]
Referências encontradas : 8 [refinar]
Mostrando: 1 .. 8   no formato [Detalhado]

página 1 de 1

  1 / 8 LILACS  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Texto completo
Id: lil-775118
Autor: Sethi, Bijay Kumar; Nanda, Prativa Kumari; Sahoo, Santilata.
Título: Characterization of biotechnologically relevant extracellular lipase produced by Aspergillus terreus NCFT 4269.10
Fonte: Braz. j. microbiol;47(1):143-149, Jan.-Mar. 2016. tab, graf.
Idioma: en.
Projeto: UGC-RGNF Scheme.
Resumo: Abstract Enzyme production by Aspergillus terreus NCFT 4269.10 was studied under liquid static surface and solid-state fermentation using mustard oil cake as a substrate. The maximum lipase biosynthesis was observed after incubation at 30 °C for 96 h. Among the domestic oils tested, the maximum lipase biosynthesis was achieved using palm oil. The crude lipase was purified 2.56-fold to electrophoretic homogeneity, with a yield of 8.44%, and the protein had a molecular weight of 46.3 kDa as determined by SDS-PAGE. Enzyme characterization confirmed that the purified lipase was most active at pH 6.0, temperature of 50 °C, and substrate concentration of 1.5%. The enzyme was thermostable at 60 °C for 1 h, and the optimum enzyme–substrate reaction time was 30 min. Sodium dodecyl sulfate and commercial detergents did not significantly affect lipase activity during 30-min incubation at 30 °C. Among the metal ions tested, the maximum lipase activity was attained in the presence of Zn2+, followed by Mg2+ and Fe2+. Lipase activity was not significantly affected in the presence of ethylenediaminetetraacetic acid, sodium lauryl sulfate and Triton X-100. Phenylmethylsulfonyl fluoride (1 mM) and the reducing, β-mercaptoethanol significantly inhibited lipase activity. The remarkable stability in the presence of detergents, additives, inhibitors and metal ions makes this lipase unique and a potential candidate for significant biotechnological exploitation.
Descritores: Aspergillus/enzimologia
Lipase/metabolismo
-Cátions Bivalentes/metabolismo
Eletroforese em Gel de Poliacrilamida
Estabilidade Enzimática
Ativadores de Enzimas/análise
Inibidores Enzimáticos/análise
Concentração de Íons de Hidrogênio
Lipase/química
Lipase/isolamento & purificação
Peso Molecular
Mercaptoetanol/metabolismo
Metais/metabolismo
Temperatura Ambiente
Responsável: BR1.1 - BIREME


  2 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Texto completo
Id: lil-688589
Autor: Aboubakr, Hamada A.; El-Sahn, Malak A.; El-Banna, Amr A..
Título: Some factors affecting tannase production by Aspergillus niger Van Tieghem
Fonte: Braz. j. microbiol;44(2):559-567, 2013. tab.
Idioma: en.
Resumo: One variable at a time procedure was used to evaluate the effect of qualitative variables on the production of tannase from Aspergillus niger Van Tieghem. These variables including: fermentation technique, agitation condition, tannins source, adding carbohydrates incorporation with tannic acid, nitrogen source type and divalent cations. Submerged fermentation under intermittent shaking gave the highest total tannase activity. Maximum extracellular tannase activity (305 units/ 50 mL) was attained in medium containing tannic acid as tannins source and sodium nitrate as nitrogen source at 30 ºC for 96 h. All added carbohydrates showed significant adverse effects on the production of tannase. All tested divalent cations significantly decreased tannase production. Moreover, split plot design was carried out to study the effect of fermentation temperature and fermentation time on tannase production. The results indicated maximum tannase production (312.7 units/50 mL) at 35 ºC for 96 h. In other words, increasing fermentation temperature from 30 ºC to 35 ºC resulted in increasing tannase production.
Descritores: Aspergillus niger/enzimologia
Hidrolases de Éster Carboxílico/metabolismo
-Cátions Bivalentes/metabolismo
Meios de Cultura/química
Inibidores Enzimáticos/metabolismo
Fermentação
Temperatura Ambiente
Fatores de Tempo
Responsável: BR1.1 - BIREME


  3 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Texto completo
Id: lil-447094
Autor: Dias, Decivaldo S; Coelho, Milton V.
Título: Efeito de íons Cu2+ e Zn2+ em atividade Ca-ATPásica isolada de larvas de Pachymerus nucleorum (Fabricius) (Coleoptera: Chrysomelidae, Bruchinae) / Effect of Cu2+ and Zn2+ ions in Ca-ATPase activity isolated from Pachymerus nucleorum (Fabricius) (Coleoptera: Chrysomelidae, Bruchinae) larvae
Fonte: Neotrop. entomol;36(1):65-69, Jan.-Feb. 2007. graf.
Idioma: pt.
Resumo: As ATPases, um importante alvo de inseticidas, são enzimas que hidrolisam o ATP e utilizam a energia liberada no processo para realizar algum tipo de trabalho celular. A larva de Pachymerus nucleorum (Fabricius) possui uma ATPase que apresenta alta atividade Ca-ATPásica, mas não expressa atividade Mg-ATPásica. Nesse trabalho, foi testado o efeito de íons zinco e cobre na atividade Ca-ATPásica dessa enzima. Mais de 90 por cento da atividade Ca-ATPásica foi inibida em 0,5 mM de íons cobre ou 0,25 mM de íons zinco. Na presença de EDTA, mas não na sua ausência, a inibição por zinco foi revertida pelo aumento da concentração de cálcio. A inibição por íons cobre, não foi revertida nem na presença e nem na ausência de EDTA. O tratamento da fração ATPase com cobre, previamente ao ensaio de atividade ATPásica, não inibiu a atividade Ca-ATPásica sugerindo que o íon cobre não liga diretamente a enzima. Os resultados sugerem que íons zinco e cobre formam complexo com o ATP e se ligam à enzima inibindo sua atividade Ca-ATPásica.

ATPases, an important target of insecticides, are enzymes that hydrolyze ATP and use the energy released in that process to accomplish some type of cellular work. Pachymerus nucleorum (Fabricius) larvae possess an ATPase, that presents high Ca-ATPase activity, but no Mg-ATPase activity. In the present study, the effect of zinc and copper ions in the activity Ca-ATPase of that enzyme was tested. More than 90 percent of the Ca-ATPase activity was inhibited in 0.5 mM of copper ions or 0.25 mM of zinc ions. In the presence of EDTA, but not in the absence, the inhibition by zinc was reverted with the increase of calcium concentration. The inhibition by copper ions was not reverted in the presence or absence of EDTA. The Ca-ATPase was not inhibited by treatment of the ATPase fraction with copper, suggesting that the copper ion does not bind directly to the enzyme. The results suggest that zinc and copper ions form a complex with ATP and bind to the enzyme inhibiting its Ca-ATPase activity.
Descritores: Coleópteros/enzimologia
Coleópteros/crescimento & desenvolvimento
ATPases Transportadoras de Cálcio/efeitos dos fármacos
ATPases Transportadoras de Cálcio/metabolismo
Cobre/farmacologia
Zinco/farmacologia
-Cátions Bivalentes/farmacologia
Larva/enzimologia
Limites: Animais
Responsável: BR1.1 - BIREME


  4 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Chile
Wolff, Daniel
Texto completo
Id: lil-430710
Autor: Delgado, Ricardo; Vergara, Cecilia; Wolff, Daniel.
Título: Divalent cations as modulators of neuronal excitability: Emphasis on copper and zinc
Fonte: Biol. Res;39(1):173-182, 2006. ilus.
Idioma: en.
Projeto: FONDECYT; . CIMM-ICA; . MIDEPLAN.
Resumo: Based on indirect evidence, a role for synaptically released copper and zinc as modulators of neuronal activity has been proposed. To test this proposal directly, we studied the effect of copper, zinc, and other divalent cations on voltage-dependent currents in dissociated toad olfactory neurons and on their firing rate induced by small depolarizing currents. Divalent cations in the nanomolar range sped up the activation kinetics and increased the amplitude of the inward sodium current. In the micromolar range, they caused a dose dependent inhibition of the inward Na+ and Ca2+ currents (INa and ICa) and reduced de amplitude of the Ca2+-dependent K+ outward current (ICa-K). On the other hand, the firing rate of olfactory neurons increased when exposed to nanomolar concentration of divalent cations and decreased when exposed to micromolar concentrations. This biphasic effect of divalent cations on neuronal excitability may be explained by the interaction of these ions with high and low affinity sites in voltage-gated channels. Our results support the idea that these ions are normal modulators of neuronal excitability.
Descritores: Cobre/farmacologia
Neurônios Receptores Olfatórios/efeitos dos fármacos
Zinco/farmacologia
-Anuros
Potenciais de Ação/efeitos dos fármacos
Potenciais de Ação/fisiologia
Membrana Celular
Cátions Bivalentes/farmacologia
Estimulação Elétrica
Potenciais da Membrana/efeitos dos fármacos
Potenciais da Membrana/fisiologia
Neurônios Receptores Olfatórios/fisiologia
Transdução de Sinais/fisiologia
Limites: Animais
Responsável: BR1.1 - BIREME


  5 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Chile
Texto completo
Id: lil-356880
Autor: Uzcanga, Graciela; Galan-Caridad, Jose Manuel; Noris Suarez, Karem; Bubis, Jose.
Título: Divalent cation hinder the solubilization of a tubulin kinase activity from Trypanosoma cruzi epimastigotes
Fonte: Biol. Res;36(3/4):367-379, 2003. ilus, tab, graf.
Idioma: en.
Resumo: Trypanosoma cruzi epimastigotes were extracted under various conditions in order to examine the role of divalent cations in the solubilization of microtubule proteins. When epimastigotes were homogenized in the presence of 5 mM Mg+2 and 5 mM Ca+2, a protein kinase responsible for phosphorylating tubulin, as well as the tubulin that became phosphorylated, remained tightly associated with the parasite particulate and detergent-resistant fractions. On the contrary, tubulin kinase and its substrate were predominantly released into the parasite cytosolic and detergent-soluble fractions, when epimastigotes were extracted in the presence of 5 mM EDTA and 5 mM EGTA. These evidences demonstrated a divalent cation-dependent solubilization of the enzyme responsible for the phosphorylation of tubulin in T. cruzi epimastigotes and suggested a tight association between tubulin and this kinase. Under all conditions tested, tubulin kinase activity in epimastigote extracts was lower than the addition of the corresponding value in the parasite cytosolic and membranous fractions, suggesting the presence of a kinase inhibitor or regulatory subunit which also seemed to be modulated by divalent cations. Additionally, inhibition experiments in the presence of heparin, 2,3-bisphosphoglycerate and GTP established that the parasite tubulin kinase corresponded to a protein kinase CK2.
Descritores: Proteína Quinase C
Trypanosoma cruzi
Tubulina (Proteína)
-Cátions Bivalentes
Eletroforese em Gel de Poliacrilamida
Fosforilação
Solubilidade
Limites: Animais
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  6 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Atta, A. M
Id: lil-109000
Autor: Atta, A. M; Cunha, A. P; Peixinho, S.
Título: Partial characterization of hemagglutinin activity of the marine sponge Anthosigmella varians
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;25(1):53-5, 1992. ilus.
Idioma: en.
Resumo: The marine sponge Anthosigmella varians contains proteins that agglutinate human erythrocytes irrespective of their ABO group antigens. The hemagglutination reaction depends on divalent cations andf is not inhibited by L-arabinose, D-xylose, L-rhamnose, D-galactose, D-glucose, L and D-fucose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, methyl-alpha-Dmannopiranoside, D-cellobiose, lactose, maltose, melibiose nor raffinose (33 mM each). A partial purification of the hemagglutinins with 31-fold ioncrease in SA and 80% recovery of activity was obtained after gel filtration and ion-exchange gradient elution chromatography. Hemadsorption experiments carried our with out with the semipurified fraction using glutaraldehyde-fixed human erythrocytes suggest that protein with molecular weight of 90 and 34 kDa participate in this rection
Descritores: Hemaglutininas/análise
Poríferos/química
-Brasil
Cátions Bivalentes
Cromatografia por Troca Iônica
Hemadsorção
Água do Mar
Limites: Animais
Responsável: BR26.1 - Biblioteca Central


  7 / 8 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Id: lil-82459
Autor: Klaassen L., Julieta; Maíz Gurruchaga, Alberto; Toro N., Mauricio; Acosta, Ana María.
Título: Nutrición parenteral: estabilidad de las emulsiones de lípidos en diferentes preparaciones / Parenteral nutrition: stability of fat emulsions in different preparations
Fonte: Rev. méd. Chile;117(11):1227-31, nov. 1989. tab, ilus.
Idioma: es.
Descritores: Emulsões Gordurosas Intravenosas/análise
Nutrição Parenteral
-Cátions Bivalentes
Limites: Seres Humanos
Responsável: CL1.1 - Biblioteca Central


  8 / 8 LILACS  
              first record previous record
seleciona
para imprimir
Fotocópia
Alves, K. B
Id: lil-77431
Autor: Alves, K. B; Noguti, M. A. E; Silva, M. M. P; Brandi, C. M. W.
Título: Purification and characterization of aminopeptidase activity from rat urine
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;20(6):759-61, 1987. tab.
Idioma: en.
Conferência: Apresentado em: Annual Meeting of the Federaçäo de Sociedades de Biologia Experimental, 2, Rio de Janeiro, July 8-12, 1987.
Resumo: The aminopeptidase activity of rats urine was tested using L-aminoacy1-2-naphtylamides and L-Leu-p-nitroanilide. The enzyme preparation was purified by ion-exchange and gel filtration chromatography and showed only a single active protein active protein band on 7.5% polyacrylamide gel electrophoresis. The enzyme was characterized by studying the effects of ions (divalent cations and chloride), chelating agents and -SH and -S-S- group reagents and by determining kinetic parameters (Km and Vmax for different substrates and K1 for amino acids, antibiotics and anti-inflammatory drugs)
Descritores: Aminopeptidases/antagonistas & inibidores
Aminopeptidases/urina
-Aminopeptidases/isolamento & purificação
Aminopeptidases/metabolismo
Cátions Bivalentes/farmacologia
Cinética
Limites: Ratos
Animais
Responsável: BR26.1 - Biblioteca Central



página 1 de 1
   


Refinar a pesquisa
  Base de dados : Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde