Effect of glycosylation on the biochemical properties of [beta]-xylosidases from Aspergillus versicolor

• Published in: The journal of microbiology Vol. 47; no. 3; p. 270
• Main Authors: Somera, Alexandre Favarin, Pereira, Marita Gimenez, Souza Guimarães, Luis Henrique, Polizeli, Maria De Lourdes Teixeira De Moraes, Terenzi, Héctor Francisco, Melo Furriel, Rosa Prazeres, Jorge, João Atílio
• Format: Journal Article
• Language: English
• Published: Seoul Springer Nature B.V 01-06-2009
• Subjects: Carbon; Enzymes; Proteins
• ISSN: 1225-8873; 1976-3794
• DOI: 10.1007/s12275-008-0286-9

Aspergillus versicolor grown on xylan or xylose produces two β-xylosidases with differences in biochemical properties and degree of glycosylation. We investigated the alterations in the biochemical properties of these β-xylosidases after deglycosylation with Endo-H or PNGase F. After deglycosylation, both enzymes migrated faster in PAGE or SDS-PAGE exhibiting the same Rf. Temperature optimum of xylan-induced and xylose-induced β-xylosidases was 45°C and 40°C, respectively, and 35°C after deglycosylation. The xylan-induced enzyme was more active at acidic pH. After deglycosylation, both enzymes had the same pH optimum of 6.0. Thermal resistance at 55°C showed half-life of 15 min and 9 min for xylose- and xylan-induced enzymes, respectively. After deglycosylation, both enzymes exhibited half-lives of 7.5 min. Native enzymes exhibited different responses to ions, while deglycosylated enzymes exhibited identical responses. Limited proteolysis yielded similar polypeptide profiles for the deglycosylated enzymes, suggesting a common polypeptide core with differential glycosylation apparently responsible for their biochemical and biophysical differences.