2003 Volume 67 Issue 2 Pages 406-409
The family 6 carbohydrate-binding module (CBM) of Clostridium thermocellum XynA was expressed, and the binding equilibria of the CBM with xylooligosaccharides (degree of polymerization DP=2−8) were observed by isothermal titration calorimetry (ITC) at pH 8. The association constant, Ka, increased with increasing DP from 5×103 M−1 (DP=2) to approximately 5×105 M−1 (DP=5-8) at 20°C. The Ka values at 60°C were about 1/10 of those at 20°C. The binding was found to be an enthalpy-driven reaction. The DP dependence of the thermodynamic parameters of the binding reaction suggested the size of the ligand-binding site to be 5 xylose units long.
This article cannot obtain the latest cited-by information.