Acid alpha-glucosidase from human heart.

An alpha-glucosidase maximally active at acid pH has been purified from human heart some 2,600-fold and its properties compared to a purified alpha-glucosidase from human liver. Molecular weight was evaluated using three different analytical procedures. The effect of various cations was determined. Thermal lability was evaluated using three different substrates. Affinity and hydrolysis velocity constants for maltose, glycogen and 4-methylumbelliferyl-alpha-D-glucose were determined for both preparations at optimal hydrogen ion concentration. Inhibition studies were carried out using the disaccharide turanose. From this study, we conclude there are no significant differences in molecular weight or kinetic properties between the cardiac and hepatic alpha-glucosidase enzymes.