The glycogen-amylase complex as a means of obtaining highly purified α-amylases

α-Amylases of hog pancreas, human saliva and rat parotis are specifically precipitated from crude extracts as a glycogen-enzyme complex insoluble in 40% ethanol. The specific activity (units/mg protein) of the enzymes thus precipitated approaches or is equal to that of the best crystalleine prepations. The procedure is readily carried out on a micro-scale. A method for the removal of glycogen from the complex, with the subsequent preparation of the crystalline pancreatic and parotis enzymes, is described. In the case of pancreatic amylase the enzyme-glycogen complex contains one mole of enzyme per 550 anhydroglucose units.