Properties of the recombinant a-glucosidase from Sulfolobus solfataricus in relation to starch processing
Martino, A. ; Schiraldi, C. ; Fusco, S. ; Lernia, I. Di; Costabile, T. ; Pellicano, T. ; Marotta, M. ; Generoso, M. ; Oost, J. van der; Sensen, C.W. - \ 2001
Journal of Molecular Catalysis. B, Enzymatic 11 (2001). - ISSN 1381-1177 - p. 787 - 794.
An -glucosidase activity (EC 22.214.171.124) isolated from Sulfolobus solfataricus strain MT-4 was characterised and found of interest at industrial level in the saccharification step of hydrolysis process of starch. The gene encoding for the enzyme was expressed in Escherichia coli BL21 (DE3) with a yield of 87.5 U/g of wet biomass. The recombinant cytosolic enzyme was purified to homogeneity with a rapid purification procedure employing only steps of selective and progressive thermal precipitations with a final yield of 75.4nd a purification of 14.5-fold. The properties of this thermophilic -glucosidase were compared with those of the -glucosidase of a commercial preparation from Aspergillus niger used in the starch processing.
Identification and molecular characterization of the first a-xylosidase from an Archaeon
Moracci, M. ; Cobucci-Ponzano, B. ; Trincone, A. ; Fusco, S. ; Rosa, M. de; Oost, J. van der; Sensen, C.W. ; Charlebois, R.L. ; Rossi, M. - \ 2000
Journal of Biological Chemistry 275 (2000). - ISSN 0021-9258 - p. 22082 - 22089.
We here report the first molecular characterization of an -xylosidase (XylS) from an Archaeon. Sulfolobus solfataricus is able to grow at temperatures higher than 80 °C on several carbohydrates at acidic pH. The isolated xylS gene encodes a monomeric enzyme homologous to -glucosidases, -xylosidases, glucoamylases and sucrase-isomaltases of the glycosyl hydrolase family 31. xylS belongs to a cluster of four genes in the S. solfataricus genome, including a -glycosidase, an hypothetical membrane protein homologous to the major facilitator superfamily of transporters, and an open reading frame of unknown function. The -xylosidase was overexpressed in Escherichia coli showing optimal activity at 90 °C and a half-life at this temperature of 38 h. The purified enzyme follows a retaining mechanism of substrate hydrolysis, showing high hydrolytic activity on the disaccharide isoprimeverose and catalyzing the release of xylose from xyloglucan oligosaccharides. Synergy is observed in the concerted in vitro hydrolysis of xyloglucan oligosaccharides by the -xylosidase and the -glycosidase from S. solfataricus. The analysis of the total S. solfataricus RNA revealed that all the genes of the cluster are actively transcribed and that xylS and orf3 genes are cotranscribed.
An Lrp-like protein of the hyperthermophilic archaeon Sulfolobus solfataricus which binds to its own promoter
Napoli, A. ; Oost, J. van der; Sensen, C.W. ; Charlebois, R.L. ; Rossi, M. ; Ciaramella, M. - \ 1999
Journal of Bacteriology 181 (1999). - ISSN 0021-9193 - p. 1474 - 1480.
|Completing the sequence of the Sulfolobus solfataricus P2 genome.
Sensen, C.W. ; Charlebois, R.L. ; Chow, C. ; Clausen, I.G. ; Curtis, B. ; Doolittle, W.F. ; Duguet, M. ; Erauso, G. ; Gaasterland, T. ; Garrett, R.A. ; Gordon, P. - \ 1998
Extremophiles 2 (1998). - ISSN 1431-0651 - p. 305 - 312.