α-Amylase adsorption on starch crystallites
Article first published online: 19 FEB 2004
Copyright © 1991 John Wiley & Sons, Inc.
Biotechnology and Bioengineering
Volume 38, Issue 2, pages 127–134, 20 June 1991
How to Cite
Leloup, V. M., Colonna, P. and Ring, S. G. (1991), α-Amylase adsorption on starch crystallites. Biotechnol. Bioeng., 38: 127–134. doi: 10.1002/bit.260380204
- Issue published online: 19 FEB 2004
- Article first published online: 19 FEB 2004
- Manuscript Accepted: 29 NOV 1990
- Manuscript Received: 18 APR 1990
- Bacillus subtillis;
- binding free energy;
- Adsorption isotherm;
- monolayer adsorption process
The goal of this work was to characterize the adsorption of Bacillus subtills α-amylase onto crystalline starchy materials of the B-type polymorph. Monodisperse spherulitic particles (R ż6; 5.0 μm), essentially resistant to α-amylolysis at 25°C were prepared from short amylose chains (DPn ≈ 15). The α-amylase adsorbed specifically onto the spherulites, and adsorption was found to be a prerequisite step for hydrolysis. Adsorption was inhibited by the presence of maltose and maltotriose in the reaction mixture. Adsorption isotherm of the enzyme on the particles showed a well developed plateau of 1.62 μg/cm2 at 25°C corresponding to a monolayer adsorption process. The binding free energy calculated from the initial slope of the isotherm was ΔG ≈ −20.7 kJ/mol. This is smaller than published values for the binding of α-amylase to soluble amylosic chains (ΔG < −30 kJ/mol).