arylesterases

Arylesterases are enzymes that catalyze the hydrolysis of aryl esters, chemical compounds in which an aromatic ring is linked to an acyl group by an ester bond. The reaction adds a molecule of water across the ester linkage, producing an alcohol (often a phenol) and a carboxylate. Arylesterases are a subset of esterases and other serine hydrolases and are commonly studied as models of catalytic efficiency and substrate specificity.

Most arylesterases belong to serine hydrolase families that use a catalytic Ser-His-Asp (or Glu) triad. The mechanism typically involves formation of an acyl-enzyme intermediate, followed by nucleophilic attack by water to release the hydrolyzed products and regenerate the active enzyme. Many arylesterases adopt the alpha/beta hydrolase fold, but the broader class can include enzymes with varying active-site architectures.

Arylesterases are distributed across bacteria, fungi, plants, and animals, and may be soluble, periplasmic, or secreted in different organisms. They act on a range of aryl esters, such as phenyl esters and substituted phenyl esters, with substrate preferences that reflect differences in acyl and leaving-group size and electronics. Common assay substrates include p-nitrophenyl esters, where product formation is monitored spectrophotometrically.

Applications and significance include roles in detoxification and metabolism of aromatic esters, bioremediation of environmental pollutants, and use in industrial or biotechnological processes that involve ester hydrolysis or the production of phenolic compounds. The term arylesterase is sometimes used variably in literature, and enzymes with broader substrate ranges may be described in relation to related esterases or oxidoreductases.