Carboxylesterase

In enzymology, a carboxylesterase is an enzyme that catalyzes the chemical reaction


 * a carboxylic ester + H2O $$\rightleftharpoons$$ an alcohol + a carboxylate

Thus, the two substrates of this enzyme are carboxylic ester and H2O, whereas its two products are alcohol and carboxylate.

Most enzymes from this group belong to the superfamily of hydrolases with alpha/beta protein fold (so called Alpha/beta hydrolase fold), specifically those acting on carboxylic ester bonds. Some exceptions include an esterase with beta-lactamase like structure. The carboxylesterase family of evolutionarily related proteins (those with clear sequence homology to each other) includes a number of proteins with different substrate specificities, such as acetylcholinesterases. The systematic name of this enzyme class is carboxylic-ester hydrolase. Examples of of carboxyesterases include ali-esterase, B-esterase, monobutyrase, procaine esterase, methylbutyrase, vitamin A esterase, butyryl esterase, carboxyesterase, carboxylate esterase, carboxylic esterase, methylbutyrate esterase, triacetin esterase, carboxyl ester hydrolase, butyrate esterase, methylbutyrase, alpha-carboxylesterase, propionyl esterase, nonspecific carboxylesterase, esterase D, esterase B, esterase A, serine esterase, carboxylic acid esterase, and cocaine esterase. The last enzyme participates in alkaloid biosynthesis.

Structural studies
As of late 2007, 38 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and.