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| Fanchini Terrasan,César Rafael; Guisan,José Manuel; Cano Carmona,Eleonora. |
| Background: Xylanases and β-D-xylosidases are the most important enzymes responsible for the degradation of xylan, the second main constituent of plant cell walls. Results: In this study, the main extracellular xylanase (XYL I) and p-xylosidase (BXYL I) from the fungus Penicillium janczewskii were purified, characterized and applied for the hydrolysis of different substrates. Their molecular weights under denaturing and non-denaturing conditions were, respectively, 30.4 and 23.6 kDa for XYL I, and 100 and 200 kDa for BXYL I, indicating that the latter is homodimeric. XYL I is highly glycosylated (78%) with optimal activity in pH 6.0 at 65°C, while BXYL I presented lower sugar content (10.5%) and optimal activity in pH 5.0 at 75°C. The half-lives... |
| Tipo: Journal article |
Palavras-chave: Xylanolytic enzymes; Enzyme characterization; Enzyme purification; Xylan hydrolysis; Xylooligosaccharides hydrolysis. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000500006 |
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| Silva,L.A.O; Terrasan,César Rafael Fanchini; Carmona,Eleonora Cano. |
| Background Two xylanases, Xyl I and Xyl II, were purified from the crude extracellular extract of a Trichoderma inhamatum strain cultivated in liquid medium with oat spelts xylan. Results The molecular masses of the purified enzymes estimated by SDS-PAGE and gel filtration were, respectively, 19 and 14 kDa for Xyl I and 21 and 14.6 kDa for Xyl II. The enzymes are glycoproteins with optimum activity at 50°C in pH 5.0-5.5 for Xyl I and 5.5 for Xyl II. The xylanases were very stable at 40°C and in the pH ranges from 4.5-6.5 for Xyl I and 4.0-8.0 for Xyl II. The ion Hg2+ and the detergent SDS strongly reduced the activity while 1,4-dithiothreitol stimulated both enzymes. The xylanases showed specificity for xylan, Km and Vmax of 14.5, 1.6 mg·mL-1 and 2680.2... |
| Tipo: Journal article |
Palavras-chave: Enzyme purification; Physico-chemical properties; Trichoderma inhamatum; Xylanases. |
| Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000400009 |
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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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| Sudério,Fabrício Bonfim; Barbosa,Gislainy Karla da Costa; Gomes-Filho,Enéas; Enéas-Filho,Joaquim. |
| Three β-galactosidase isoforms, β-gal I and β-gal II (cytosolic) and β-gal III (cell wall-associated), were isolated from stems of Vigna unguiculata (L.) Walp. cv. Pitiúba seedlings. Purification consisted of aμMonia sulfate fractionation followed by chromatography in DEAE-Sephadex and Lactosyl-Sepharose columns. The two cytosolic isoforms showed the same chromatography pattern, which differed from that of β-gal III. Electrophoresis revealed a single band of protein for β-gal II and β-gal III which also expressed β-galactosidase activity in gel. The apparent molecular mass of the β-gal I, II and III was 89, 146 and 124 kDa, respectively. The three isoforms revealed the same optimal pH (4.0) and the same optimal assay temperature (55ºC) for enzyme activity.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzymatic kinetics; Cowpea; Optimal pH; Enzyme purification; Thermal stability; Thermal inactivation. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100003 |
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