Effect of adsorption of an inhibitory factor on raw starch hydrolysis by glucoamylase
S Towprayoon1, Y Fujio, S Ueda
1Department of Food Science and Technology, Faculty of Agriculture, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, 812, Fukuoka, Japan.
Abstract:
An inhibitory factor (IF) produced byAspergillus niger strain 19, and which inhibits the action of glucoamylase on starch, has the ability to be tightly adsorbed on to various raw starches, though the amount differs from starch to starch. Based on the hydrolysis of the IF-starch complex by glucoamylase, the inhibitions per unit IF adsorbed are similar for some varieties of starch. The effectiveness ratio of IF (% hydrolysis inhibition per % IF adsorbed on raw starch) for corn, sweet potato, waxy rice and waxy corn starches are 1.1, 1.0, 0.85 and 0.96, respectively. These results support the hypothesis that both glucoamylase and IF are adsorbed on to a common binding site on raw starch. However, the effectiveness ratio of IF for cassava and wheat starches are 0.71 and 1.65, respectively, which differ significantly from other varieties of starch.
Related Concept Videos
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are...
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex,...
Enzyme Inhibition
Feedback Inhibition
GPCRs Regulate Adenylyl Cylase Activity
Carbohydrate Digestion


