alphaamylase

Alpha-amylase, also known as α-amylase, is an enzyme that catalyzes the hydrolysis of alpha-1,4-glycosidic bonds in starch and related polysaccharides, producing maltose, maltotriose, and dextrins. It cannot cleave the alpha-1,6-glycosidic linkages found at branch points.

In humans, alpha-amylase is produced by the salivary glands (salivary amylase, or ptyalin) and by the pancreas (pancreatic alpha-amylase) and is active in the mouth and small intestine. The enzyme is also widely produced by microorganisms and plants and is used industrially in brewing, baking, and syrup production; commercial preparations are often derived from Aspergillus oryzae or from Bacillus species.

Biochemically, alpha-amylase belongs to glycoside hydrolase family 13 and uses a catalytic aspartate–glutamate pair in its active site to cleave alpha-1,4-glycosidic bonds. Calcium ions stabilize the enzyme's structure and activity. The enzyme generally has optimal activity at around neutral pH and near physiological temperatures; industrial variants may be engineered for higher temperature stability.

Beyond digestion, alpha-amylase is used in diagnostic laboratories to assess pancreatobiliary function and in starch-processing industries for starch liquefaction during fermentation and baking.