Microcalorimetric study of the enzymatic hydrolysis of starch: An α-amylase catalyzed reaction

Microcalorimetric studies of enzyme activities have been made on the hydrolysis of starch catalyzed by α-amylase. The best conditions for the hydrolysis of starch in the presence of α-amylase have been pointed out and the α-amylase activity was determined by isothermal batch microcalorimetry. The heat changes involved during the hydrolytic reaction can be related to the starch concentrations in a linear way and the heights of the calorimetric curves can be directly related to the amylase activities. Calibration curves were obtained. The new method for starch assay and α-amylase activity determination is direct, simple, accurate and it needs no pretreatment of the sample or auxiliary reactions. The α-amylase catalytic activity has also been investigated by microcalorimetry in the presence of some metal ions.