Amylaasit

Amylaasit, or amylases, are a group of enzymes that catalyze the hydrolysis of starch and related polysaccharides into smaller sugars. The best-known members are alpha-amylases, beta-amylases, and glucoamylases (sometimes called gamma-amylases in certain contexts). Alpha-amylases act internally on starch to produce dextrins and maltose; beta-amylases work from the non-reducing ends to release maltose; glucoamylases release glucose from non-reducing ends. Amylases are found in many organisms, including plants, fungi, bacteria, and animals.

In humans, the primary amylases are salivary amylase and pancreatic alpha-amylase. Salivary amylase begins starch digestion in the mouth, while pancreatic alpha-amylase continues this process in the small intestine. Amylases are typically active under near-neutral conditions and require calcium ions for stability; chloride ions can enhance the activity of human salivary amylase.

Structure and mechanism: amylases are glycoside hydrolases that use a catalytic set of acidic residues, usually an aspartate and a glutamate, to cleave glycosidic bonds in a two-step mechanism. The enzymes are often secreted or secreted-in-activated forms and may be stabilized by metal ions.

Applications: amylases are widely used in industry, including baking and brewing to modify starch behavior, starch processing to produce sugars, and detergents for stain removal. They are also used in research and diagnostic contexts.

Discovery: the enzyme family was described in 1833 by Anselme Payen and Jean Persoz for the breakdown of starch, a foundational moment in enzymology.