The action of human pancreatic and salivary isoamylases on starch and glycogen.

The hydrolytic properties of the isoenzymes of human pancreatic and salivary alpha-amylase (1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) were studied. The eight pancreatic isoenzymes split glycogen and starch into glucose, maltose, maltotriose, maltotetraose and oligosaccharides of 5-10 glucose units. Maltotetraose is further digested to lower homologues. The percentage of conversion to those products is dependent on the substrate and varies from one isoenzyme to another. The six salivary isoenzymes split glycogen and starch into maltose, maltotriose, maltotetraose, pannose and oligosaccharides of 5--10 glucose units. Maltotetraose and pannose are further digested to lower homologues. The percentage of conversion to these products is dependent on the substrate and is specific for each isoenzyme.