esterasas

Esterases (esterasas in Portuguese) are a broad group of enzymes that catalyze the hydrolysis of ester bonds in a wide range of substrates, including natural esters such as lipids and pheromones, as well as synthetic compounds. They belong to the hydrolase class of enzymes (EC 3.1) and are diverse in structure and specificity. Most esterases act on relatively small to medium-sized esters and use a catalytic mechanism that frequently involves a nucleophilic serine residue within a conserved α/β hydrolase fold.

Among esterases, several major families are well characterized. Cholinesterases, such as acetylcholinesterase and butyrylcholinesterase, hydrolyze neurotransmitters and related esters in the nervous system. Carboxylesterases, including CES1 and CES2 in mammals, participate in detoxification and drug metabolism by hydrolyzing ester prodrugs and xenobiotics. Other groups include arylesterases and paraoxonases, as well as numerous microbial esterases that contribute to nutrient utilization and biocatalysis.

Biological roles of esterases extend from digestion and metabolism to detoxification and signaling. In humans, esterases help process dietary esters, activate or inactivate drugs, and defend against ester-containing toxins. In non-human organisms, esterases influence development, pheromone signaling, and the breakdown of environmental esters.

Industrial and research applications rely on esterases for biocatalysis, including enantioselective hydrolysis and synthesis of esters, degradation of esthetic compounds, and production of pharmacologically relevant metabolites. In pharmacology and toxicology, esterase activity affects drug disposition, interactions, and responses, and esterases are considered in drug design and safety assessments.

Clinical relevance includes inhibition of cholinesterases by organophosphates, which disrupt neural signaling and can cause severe toxicity. Genetic variation and individual expression patterns of esterases influence drug clearance and prodrug activation, making esterases a focus of personalized medicine and toxicology research.