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Biochemical and molecular characterization of secreted α-xylosidase from Aspergillus niger.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2011 Dec 16; Vol. 286 (50), pp. 42848-54. Date of Electronic Publication: 2011 Oct 27. - Publication Year :
- 2011
-
Abstract
- α-Linked xylose is a major component of xyloglucans in the cell walls of higher plants. An α-xylosidase (AxlA) was purified from a commercial enzyme preparation from Aspergillus niger, and the encoding gene was identified. The protein is a member of glycosyl hydrolase family 31. It was active on p-nitrophenyl-α-d-xyloside, isoprimeverose, xyloglucan heptasaccharide (XXXG), and tamarind xyloglucan. When expressed in Pichia pastoris, AxlA had activity comparable to the native enzyme on pNPαX and IP despite apparent hyperglycosylation. The pH optimum of AxlA was between 3.0 and 4.0. AxlA together with β-glucosidase depolymerized xyloglucan heptasaccharide. A combination of AxlA, β-glucosidase, xyloglucanase, and β-galactosidase in the optimal proportions of 51:5:19:25 or 59:5:11:25 could completely depolymerize tamarind XG to free Glc or Xyl, respectively. To the best of our knowledge, this is the first characterization of a secreted microbial α-xylosidase. Secreted α-xylosidases appear to be rare in nature, being absent from other tested commercial enzyme mixtures and from the genomes of most filamentous fungi.
- Subjects :
- Cellulases metabolism
Fungal Proteins genetics
Galactosidases metabolism
Glucosidases metabolism
Glycoside Hydrolases metabolism
Pichia genetics
Pichia metabolism
Tamarindus chemistry
Xylosidases genetics
Aspergillus niger enzymology
Fungal Proteins metabolism
Glucans metabolism
Xylans metabolism
Xylosidases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 286
- Issue :
- 50
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 22033931
- Full Text :
- https://doi.org/10.1074/jbc.M111.307397