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Registro Completo |
Biblioteca(s): |
Embrapa Agrobiologia. |
Data corrente: |
14/05/1996 |
Data da última atualização: |
14/05/1996 |
Autoria: |
SAMPAIO, M. J. A. M. |
Título: |
Studies on Cyanobacterial glutamine synthetase. |
Ano de publicação: |
1979 |
Fonte/Imprenta: |
Dundee: University of Dundee, Agosto, 1979. |
Páginas: |
161p. |
Série: |
Tese de Doutorado. |
Idioma: |
Inglês |
Notas: |
Orientada por: W.D.P. Stwart. |
Conteúdo: |
Glutamine synthetase has been purified to homogeneity from three cyanobacteria: Anabaena cylindrica, a species of Nostoc (isolated from the lichen Peltigera canina) and Plectonema boryanum. The activities of the A. cylindrica, Nostoc sp and P. boryanum enzymes in the biosynthetic assay were, respectively, 9.4, 6.5 and 5.0 umol product formed. mg protein -1.min-1. Stabilization of the enzyme required Mg2+, glutamate, EDTA and a thiol reagent to be present during purification. The molecular weight of the A. cylindrica enzyme was 591,000 as estimated by sedimentation analysis, 660,000 by gel filtration and 565,000 by polyacrylamide gel electrophoresis; the Nostoc sp and P. boryanum enzymes gave values in the same region. The molecular weights of the sub-units ofeach enzyme were approximately 50,000. Electron microscopy revealed that each molecule was composed of 12 sub-units arranged in two superimposed hexagonal rings. When dialysed in the absence of stabilizing ligands the A. cylindrica enzyme lost activity and the protein band characteristic of the native enzyme was replaced by three bands with approximate molecular weights of 510,000, 310,000, and 130,000. These sub-species re-associated and activity was restored by adding 2-mercaptoethanol and substrates. The Nostoc sp and P. boryanum enzymes did not show such deactivation.Some kinetic and regulatory properties of the purified A. cylindrica, Nostoc and P. boryanum glutamine synthetases were determined. The feed-back inhibition pattern observed with.............. MenosGlutamine synthetase has been purified to homogeneity from three cyanobacteria: Anabaena cylindrica, a species of Nostoc (isolated from the lichen Peltigera canina) and Plectonema boryanum. The activities of the A. cylindrica, Nostoc sp and P. boryanum enzymes in the biosynthetic assay were, respectively, 9.4, 6.5 and 5.0 umol product formed. mg protein -1.min-1. Stabilization of the enzyme required Mg2+, glutamate, EDTA and a thiol reagent to be present during purification. The molecular weight of the A. cylindrica enzyme was 591,000 as estimated by sedimentation analysis, 660,000 by gel filtration and 565,000 by polyacrylamide gel electrophoresis; the Nostoc sp and P. boryanum enzymes gave values in the same region. The molecular weights of the sub-units ofeach enzyme were approximately 50,000. Electron microscopy revealed that each molecule was composed of 12 sub-units arranged in two superimposed hexagonal rings. When dialysed in the absence of stabilizing ligands the A. cylindrica enzyme lost activity and the protein band characteristic of the native enzyme was replaced by three bands with approximate molecular weights of 510,000, 310,000, and 130,000. These sub-species re-associated and activity was restored by adding 2-mercaptoethanol and substrates. The Nostoc sp and P. boryanum enzymes did not show such deactivation.Some kinetic and regulatory properties of the purified A. cylindrica, Nostoc and P. boryanum glutamine synthetases were determined. The feed-back inhib... Mostrar Tudo |
Palavras-Chave: |
Cianobactéria; Cyanophyta; Glutamine sythetase; Purification. |
Thesagro: |
Bactéria; Enzima; Extração; Purificação. |
Thesaurus Nal: |
analytical methods; enzymes. |
Categoria do assunto: |
-- |
Marc: |
LEADER 02230nam a2200265 a 4500 001 1621455 005 1996-05-14 008 1979 bl uuuu m 00u1 u #d 100 1 $aSAMPAIO, M. J. A. M. 245 $aStudies on Cyanobacterial glutamine synthetase. 260 $aDundee: University of Dundee, Agosto$c1979 300 $a161p. 490 $aTese de Doutorado. 500 $aOrientada por: W.D.P. Stwart. 520 $aGlutamine synthetase has been purified to homogeneity from three cyanobacteria: Anabaena cylindrica, a species of Nostoc (isolated from the lichen Peltigera canina) and Plectonema boryanum. The activities of the A. cylindrica, Nostoc sp and P. boryanum enzymes in the biosynthetic assay were, respectively, 9.4, 6.5 and 5.0 umol product formed. mg protein -1.min-1. Stabilization of the enzyme required Mg2+, glutamate, EDTA and a thiol reagent to be present during purification. The molecular weight of the A. cylindrica enzyme was 591,000 as estimated by sedimentation analysis, 660,000 by gel filtration and 565,000 by polyacrylamide gel electrophoresis; the Nostoc sp and P. boryanum enzymes gave values in the same region. The molecular weights of the sub-units ofeach enzyme were approximately 50,000. Electron microscopy revealed that each molecule was composed of 12 sub-units arranged in two superimposed hexagonal rings. When dialysed in the absence of stabilizing ligands the A. cylindrica enzyme lost activity and the protein band characteristic of the native enzyme was replaced by three bands with approximate molecular weights of 510,000, 310,000, and 130,000. These sub-species re-associated and activity was restored by adding 2-mercaptoethanol and substrates. The Nostoc sp and P. boryanum enzymes did not show such deactivation.Some kinetic and regulatory properties of the purified A. cylindrica, Nostoc and P. boryanum glutamine synthetases were determined. The feed-back inhibition pattern observed with.............. 650 $aanalytical methods 650 $aenzymes 650 $aBactéria 650 $aEnzima 650 $aExtração 650 $aPurificação 653 $aCianobactéria 653 $aCyanophyta 653 $aGlutamine sythetase 653 $aPurification
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Registro original: |
Embrapa Agrobiologia (CNPAB) |
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Registros recuperados : 6 | |
4. | | INOUE, M. H.; SANTANA, D. C.; SOUZA FILHO, A. P. S.; POSSAMAI, A. C. S.; SILVA, L. E.; PEREIRA, M. J. B.; PEREIRA, K. M. Potencial alelopático de Annona crassiflora: efeitos sobre plantas daninhas. Planta daninha, Viçosa, MG, v. 28, n. 3, p. 489-498, 2010.Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
Biblioteca(s): Embrapa Amazônia Oriental. |
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5. | | SILVA, J. V. L. da; DALLACORT, R.; INOUE, M. H.; OLIVEIRA, M. A. de; AZEVEDO, V. H. de; ALMEIDA, R. G. de. Produção de forragem e valor nutritivo do capim-marandu submetido a doses de torta de pinhão manso. In: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 46., 2009, Maringá. Inovação científica e tecnológica em zootecnia: anais dos resumos. Maringá: SBZ: UEM, 2009. 3 p. 1 CD-ROM.Tipo: Artigo em Anais de Congresso / Nota Técnica |
Biblioteca(s): Embrapa Gado de Corte. |
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6. | | INOUE, M. H.; SANTANA, D. C.; VILHENA, K. S. S.; SOUZA FILHO, A. P. S.; GUILHON, G. M. S. P.; POSSAMAI, A. C. S.; SILVA, L. E.; DALLACORT, R. Avaliação do potencial alelopático de substâncias isoladas em sementes de Araticum (Annona crassiflora). Planta daninha, Viçosa, MG, v. 28, n. 4, p. 735-741, 2010.Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
Biblioteca(s): Embrapa Amazônia Oriental. |
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Registros recuperados : 6 | |
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