dc.creator | SILVA, Tony Marcio da | |
dc.creator | MICHELIN, Michele | |
dc.creator | DAMASIO, Andre Ricardo de Lima | |
dc.creator | MALLER, Alexandre | |
dc.creator | ALMEIDA, Fausto Bruno Dos Reis | |
dc.creator | RULLER, Roberto | |
dc.creator | WARD, Richard John | |
dc.creator | ROSA, Jose Cesar | |
dc.creator | JORGE, Joao Atilio | |
dc.creator | TERENZI, Hector Francisco | |
dc.creator | POLIZELI, Maria de Lourdes Teixeira de Moraes | |
dc.date.accessioned | 2012-10-19T14:13:00Z | |
dc.date.accessioned | 2018-07-04T15:00:19Z | |
dc.date.available | 2012-10-19T14:13:00Z | |
dc.date.available | 2018-07-04T15:00:19Z | |
dc.date.created | 2012-10-19T14:13:00Z | |
dc.date.issued | 2009 | |
dc.identifier | ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY, v.96, n.4, p.569-578, 2009 | |
dc.identifier | 0003-6072 | |
dc.identifier | http://producao.usp.br/handle/BDPI/20660 | |
dc.identifier | 10.1007/s10482-009-9372-1 | |
dc.identifier | http://dx.doi.org/10.1007/s10482-009-9372-1 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1617439 | |
dc.description.abstract | An extracellular alpha-glucosidase produced by Aspergillus niveus was purified using DEAE-Fractogel ion-exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5% PAGE and 10% SDS-PAGE. The enzyme presented 29% of glycosylation, an isoelectric point of 6.8 and a molecular weight of 56 and 52 kDa as estimated by SDS-PAGE and Bio-Sil-Sec-400 gel filtration column, respectively. The enzyme showed typical alpha-glucosidase activity, hydrolyzing p-nitrophenyl alpha-d-glucopyranoside and presented an optimum temperature and pH of 65A degrees C and 6.0, respectively. In the absence of substrate the purified alpha-glucosidase was stable for 60 min at 60A degrees C, presenting t (50) of 90 min at 65A degrees C. Hydrolysis of polysaccharide substrates by alpha-glucosidase decreased in the order of glycogen, amylose, starch and amylopectin. Among malto-oligosaccharides the enzyme preferentially hydrolyzed malto-oligosaccharide (G10), maltopentaose, maltotetraose, maltotriose and maltose. Isomaltose, trehalose and beta-ciclodextrin were poor substrates, and sucrose and alpha-ciclodextrin were not hydrolyzed. After 2 h incubation, the products of starch hydrolysis measured by HPLC and thin layer chromatography showed only glucose. Mass spectrometry of tryptic peptides revealed peptide sequences similar to glucan 1,4-alpha-glucosidases from Aspergillus fumigatus, and Hypocrea jecorina. Analysis of the circular dichroism spectrum predicted an alpha-helical content of 31% and a beta-sheet content of 16%, which is in agreement with values derived from analysis of the crystal structure of the H. jecorina enzyme. | |
dc.language | eng | |
dc.publisher | SPRINGER | |
dc.relation | Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology | |
dc.rights | Copyright SPRINGER | |
dc.rights | restrictedAccess | |
dc.subject | Aspergillus niveus | |
dc.subject | alpha-Glucosidase | |
dc.subject | Purification | |
dc.subject | Thermostability | |
dc.subject | Fungus | |
dc.title | Purification and biochemical characterization of a novel alpha-glucosidase from Aspergillus niveus | |
dc.type | Artículos de revistas | |