All-reagent test tablets and method for rapid and selective alpha-amylase iodometric determination

Area of Science:

• Biochemistry
• Enzymology

Background:

• Alpha-amylase is a key enzyme in carbohydrate metabolism.
• Existing methods for alpha-amylase assay have limitations.

Purpose of the Study:

• To introduce a novel test tablet (Iodocrom) for alpha-amylase assay.
• To describe the amyloclastic principle of this new assay.

Main Methods:

• Utilized crosslinked (CL)-amylose or CL-starch as specific substrates for alpha-amylase.
• Employed a potassium iodate/potassium iodide (KIO3/KI) reagent to generate iodine upon reaction termination.
• Monitored the reaction by observing an increase in blue color due to iodine inclusion complexes.

Main Results:

• The method is based on the selective action of alpha-amylase on CL-substrates, releasing soluble polysaccharide chains.
• Formation of iodine inclusion complexes with these chains leads to a measurable increase in blue color.
• Enzyme activity showed a linear dependence on the concentration of released chains and the absorbance of their iodine complexes.

Conclusions:

• The Iodocrom test tablets provide a new amyloclastic method for alpha-amylase determination.
• This method offers an alternative to existing chromogenic and iodometric assays.
• The assay is sensitive to enzyme concentration, with results correlating linearly with activity.