noun, plural: alpha-amylases
A form of amylase in humans and other mammals that cuts alpha-bonds of large sugar molecules.
In animals, the alpha-amylases are major digestive enzymes. The ptyalin (salivary amylase) and pancreatic amylase are examples of alpha-amylase. Ptyalin acts on linear α (1,4) glycosidic linkage to break large, insoluble starch molecules into soluble starches (amylodextrin, erythrodextrin, achrodextrin) producing successively smaller starches. Pancreatic α-amylase randomly cleaves the α (1-4) glycosidic linkages of amylose to yield dextrin, maltose or maltotriose. Alpha-amylases are calcium metalloenzymes, which means, they function only in the presence of calcium.
They are also found in plants, such as barley, and fungi (ascomycetes and basidiomycetes).
“Synonym:” 1,4-α-D-glucan glucanohydrolase