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Updated: Jul 3, 2026
08:46
Analysis and Specification of Starch Granule Size Distributions
Published on: March 4, 2021
alpha-Amylase adsorption on starch crystallites
V M Leloup1, P Colonna, S G Ring
1Institut National de la Recherche Agronomique, BP 527-44026 Nantes Cedex 03, France.
Biotechnology and Bioengineering
|June 20, 1991
Summary
Bacillus subtilis alpha-amylase specifically adsorbs to B-type crystalline starch spherulites, a necessary step for hydrolysis. This enzyme adsorption is inhibited by maltose and maltotriose, with a binding free energy of -20.7 kJ/mol.
Area of Science:
- Biochemistry
- Enzymology
- Carbohydrate Chemistry
Background:
- Starch structure and enzymatic hydrolysis are crucial in food and biofuel industries.
- Understanding enzyme-starch interactions is key to optimizing industrial processes.
- Bacillus subtilis alpha-amylase is a significant industrial enzyme.
Purpose of the Study:
- To characterize the adsorption of Bacillus subtilis alpha-amylase onto B-type crystalline starch.
- To determine if adsorption is a prerequisite for starch hydrolysis.
- To quantify the adsorption process and binding thermodynamics.
Main Methods:
- Preparation of monodisperse spherulitic starch particles from short amylose chains.
- Enzyme adsorption assays at 25°C.
- Analysis of adsorption isotherms and calculation of binding free energy.
Main Results:
- Alpha-amylase specifically adsorbed onto starch spherulites, preceding hydrolysis.
- Adsorption was inhibited by maltose and maltotriose.
- A monolayer adsorption plateau of 1.62 μg/cm² was observed.
- The binding free energy (ΔG) was approximately -20.7 kJ/mol.
Conclusions:
- Enzyme adsorption is essential for Bacillus subtilis alpha-amylase mediated hydrolysis of crystalline starch.
- The binding affinity to crystalline starch is lower than to soluble starch chains.
- These findings provide insights into enzyme-substrate interactions for starch modification.
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