(1,4-a-D-Glucan glucanohydrolase; EC 18.104.22.168)
Alpha amylase is able to catalyze the hydrolysis of starch (amylose and amylopectin) to a significant extent resulting in the release of maltose. The enzyme is found in nearly all plants, animals and microorganisms. The enzymes from various sources exhibit marked differences in physical, chemical and catalytic properties. Bacterial amylases and those from porcine pancreas and human saliva have been extensively studied. Alpha amylase from porcine pancreas has a molecular weight of about 50,000 and it exhibits optimum catalytic activity at pH 7.0. The E 1%/280 is 26.0 (Cadwell, et al, J. Am Chem Soc, 74, 4033, 1952).
Alpha amylase is widely used in the food industry as a clarifying agent. Determination of serum alpha amylase activity, for the diagnosis of acute pancreatitis, is a widely used procedure in clinical medicine (Brooks, F., New Eng. J. Med., 286, 300, 1972). Additionally, it has been reported that elevated alpha amylase activity in serum also occurs in mumps, renal disease and abdominal disorders such as cholecystitis (Salt, W. and Schenkder, S., Medicine, 55, 269, 1978).