Purification and characterization of two beta-glucosidases from the thermophilic fungus Thermoascus aurantiacus
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
20/05/2014
20/05/2014
01/01/2002
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Resumo |
beta-Glucosidase from the fungus Thermoascus aurantiacus grown oil semi-solid fermentation medium (using ground corncob as substrate) was partially purified in 5 steps - ultrafiltration, ethanol precipitation, gel filtration and 2 anion exchange chromatography runs, and characterized. After the first anion exchange chromatography, beta-glucosidase activity was eluted in 3 peaks (Gl-1, Gl-2, Gl-3). Only the Gl-2 and Gl-3 fractions were adsorbed on the gel matrix. Gl-2 and Gl-3 exhibited optimum pH at 4.5 and 4.0, respectively. The temperature optimum of both glucosidases was at 75-80 degreesC. The pH stability of Gl-2 (4.0-9.0) was higher than Gl-3 (5.5-8.5); both enzyme activities showed similar patterns of thermostability. Under conditions of denaturing gel chromatography the molar mass of Gl-2 and Gl-3 was 175 and 157 kDa, respectively. Using 4-nitrophenyl beta-D-glucopyranoside as substrate, K-m, values of 1.17 +/- 0.35 and 1.38 +/- 0.86 mmol/L were determined for Gl-2 and Gl-3, respectively. Both enzymes were inhibited by Ag+ and stimulated by Ca2+. |
Formato |
685-690 |
Identificador |
http://www.ncbi.nlm.nih.gov/pubmed/12630320 Folia Microbiologica. Prague 4: Folia Microbiologica, v. 47, n. 6, p. 685-690, 2002. 0015-5632 http://hdl.handle.net/11449/39202 WOS:000180567100010 |
Idioma(s) |
eng |
Publicador |
Folia Microbiologica |
Relação |
Folia Microbiologica |
Direitos |
closedAccess |
Tipo |
info:eu-repo/semantics/article |