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| ENÉAS-FILHO,JOAQUIM; SUDÉRIO,FABRÍCIO BONFIM; GOMES-FILHO,ENÉAS; PRISCO,JOSÉ TARQUÍNIO. |
| Cotyledonary b-galactosidases were isolated and partially purified from Pitiúba cowpea (Vigna unguiculata (L.) Walp.) quiescent seeds. The purification steps consisted of precipitation of the crude extract with ammonium sulphate in the range of 20-60% saturation, acid precipitation, DEAE-Sephadex ion-exchange chromatography and Lactosyl-Sepharose affinity chromatography. This purification process gave rise to three b-galactosidases-rich fractions: b-gal I, b-gal II and b-gal III, which were purified about 5, 509, and 62 fold, respectively. They reached maximal enzyme activity at different pH ranges: 3.5-4.5 for b-gal I, 3.0-3.5 for b-gal II, and 3.0-4.0 for b-gal III. Their maximal activities were reached when the temperature of the assay medium was 60° C,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cotyledons; Cowpea; Enzyme purification; Quiescent seeds. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042000000100008 |
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| FRANCO,OCTÁVIO LUIZ; GONDIM,LORRANCE ABREU; BEZERRA,KÁTIA REGINA; GUERRA,MARIA ELANE DE CARVALHO; LIMA,CARMEM ROGÉLIA FARIAS MACHADO; ENÉAS-FILHO,JOAQUIM; PRISCO,JOSÉ TARQUÍNIO; GOMES-FILHO,ENÉAS. |
| Partial purification and characterization of ribonucleases (RNase; EC 3.1.27.1) present in roots, stem and leaves of 5 day-old Pitiúba cowpea [Vigna unguiculata (L.) Walp.] seedlings are described. Crude extracts from the different tissues were precipitated with ammonium sulfate followed by ionic exchange chromatography (CM-Cellulose) resulting in purification factors of 48-fold for roots, 21 for stem and 42 for leaves. No deoxyribonuclease activity was practically observed. The molecular masses of the RNases did not significantly differ, averaging 16.3 kDa. Leaf RNase was stable up to 50ºC while the others were inactivated at this temperature. The maximal inactivation for both stem and roots RNases was reached at 70ºC while for leaf it occurred at 80ºC.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzyme effectors; Molecular mass; Nuclease; Optimum pH; Seedlings; Thermostability; Vigna unguiculata. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000300010 |
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| ENÉAS-FILHO,JOAQUIM; BARBOSA,GISLAINY KARLA DA COSTA; SUDÉRIO,FABRÍCIO BONFIM; PRISCO,JOSÉ TARQUÍNIO; GOMES-FILHO,ENÉAS. |
| Three isoforms of beta-galactosidases were isolated and partially purified from the cotyledons of quiescent seeds of Vita 3 and Vita 5 cowpea [Vigna unguiculata (L.) Walp.] cultivars differing in water and salt stress tolerance. The purification procedure consisted of ammonium sulfate fractionation, acid precipitation, ion exchange chromatography through DEAE-sephadex and affinity chromatography through Lactosyl-sepharose columns. The three isoforms isolated from the two cultivars showed the same chromatographic patterns, same optimum of temperature for enzyme activity assay (60ºC), identical thermal stability up to 50°C, and similar pH optima (3-4). However, they differed from each other in sensitivity towards metal ions and certain chemical agents... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cotyledons; Isozymes; Vigna unguiculata; Vita 3 and Vita 5 cultivars; Salt tolerance. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000300001 |
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