1. Enhanced Purification Efficiency and Thermal Tolerance of Thermoanaerobacterium aotearoense β-Xylosidase through Aggregation Triggered by Short Peptides.
- Author
-
Xu T, Huang X, Li Z, Ki Lin CS, and Li S
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Enzyme Stability, Hot Temperature, Hydrogen-Ion Concentration, Hydrolysis, Kinetics, Peptides metabolism, Thermoanaerobacterium chemistry, Thermoanaerobacterium genetics, Xylosidases genetics, Xylosidases metabolism, Bacterial Proteins chemistry, Bacterial Proteins isolation & purification, Peptides chemistry, Thermoanaerobacterium enzymology, Xylosidases chemistry, Xylosidases isolation & purification
- Abstract
To simplify purification and improve heat tolerance of a thermostable β-xylosidase (ThXylC), a short ELK16 peptide was attached to its C-terminus, which is designated as ThXylC-ELK. Wild-type ThXylC was normally expressed in soluble form. However, ThXylC-ELK assembled into aggregates with 98.6% of total β-xylosidase activity. After simple centrifugation and buffer washing, the ThXylC-ELK particles were collected with 92.57% activity recovery and 95% purity, respectively. Meanwhile, the wild-type ThXylC recovery yield was less than 55% after heat inactivation, affinity and desalting chromatography followed by HRV 3C protease cleavage purification. Catalytic efficiency ( K
cat / Km ) was increased from 21.31 mM-1 s-1 for ThXylC to 32.19 mM-1 s-1 for ThXylC-ELK accompanied by a small increase in Km value. Heat tolerance of ThXylC-ELK at high temperatures was also increased. The ELK16 peptide attachment resulted in 6.2-fold increase of half-life at 65 °C. Released reducing sugars were raised 1.3-fold during sugar cane bagasse hydrolysis when ThXylC-ELK was supplemented into the combination of XynAΔSLH and Cellic CTec2.- Published
- 2018
- Full Text
- View/download PDF