Abstract
Improved stability of cellulosomal enzymes is of great significance in order to provide efficient degradation of cellulosic derivatives for production of biofuels. In previous reports, we created a quadruple mutant of the endoglucanase Cel8A from Clostridium thermocellum resulting from a combination of both random error-prone PCR and a bioinformatics-based consensus mutagenesis approach. The quadruple mutant exhibited an increased half-life of activity by 14-fold at 85 °C with no apparent loss of catalytic activity compared to the wild-type form. Connection of the wild-type enzyme to its respective cohesin partner conferred increased thermostability, but no increase was observed for the cohesin-complexed mutant enzyme. The mutant and the wild-type enzymes were integrated into divalent chimeric scaffoldins with a family 48 exoglucanase partner, and the cellulose-degradation activities of resultant designer cellulosomes were examined. Despite the heightened thermostability of the mutant as a free enzyme, its substitution for the wild-type endoglucanase within the cellulosome context failed to exhibit an improvement in overall degradation of cellulose.
Original language | English |
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Pages (from-to) | 78-84 |
Number of pages | 7 |
Journal | Carbohydrate Research |
Volume | 389 |
Issue number | 1 |
DOIs | |
State | Published - 7 May 2014 |
Externally published | Yes |
Keywords
- Cellulosome
- Cohesin
- Dockerin
- Endoglucanase
- Exoglucanase
- Thermostability
ASJC Scopus subject areas
- Analytical Chemistry
- Biochemistry
- Organic Chemistry