Tannase

In enzymology, a tannase (EC 3.1.1.20) is an enzyme that catalyzes the chemical reaction

Thus, the two substrates of this enzyme are digallate and H₂O, whereas its product is gallate.

This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is tannin acylhydrolase. Other names in common use include tannase S, and tannin acetylhydrolase.

In addition to catalyzing the hydrolysis of the central ester bond between the two aromatic rings of digallate (depsidase activity), tannase may also have an esterase activity (hydrolysis of terminal ester functional groups that are attached to only one of the two aromatic rings).

Tannase is a key enzyme in the degradation of gallotannins, a type of hydrolysable tannins. It is present in a diverse group of microorganisms, including rumen bacteria.

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