Carboxylesterase
The enzyme carboxylesterase catalyzes reactions of the following form:
Most enzymes from this group are serine hydrolases belonging to the superfamily of proteins with α/β hydrolase fold. Some exceptions include an esterase with β-lactamase-like structure.
Carboxylesterases are widely distributed in nature, and are common in mammalian liver. Many participate in phase I metabolism of xenobiotics such as toxins or drugs; the resulting carboxylates are then conjugated by other enzymes to increase solubility and eventually excreted. The essential polyunsaturated fatty acid arachidonic acid, formed by the synthesis from dietary linoleic acid, has a role as a human carboxylesterase inhibitor.
The carboxylesterase family of evolutionarily related proteins includes a number of proteins with different substrate specificities, such as acetylcholinesterases.
Examples
- acetylcholinesterase
- ali-esterase,
- B-esterase,
- butyrate esterase,
- butyryl esterase,
- carboxylesterase 1
- carboxylesterase 2
- carboxylesterase 3
- esterase A,
- esterase B,
- esterase D,
- methylbutyrase,
- methylbutyrate esterase,
- monobutyrase,
- procaine esterase,
- propionyl esterase,
- triacetin esterase,
- vitamin A esterase, and
- cocaine esterase
Genes
Humans genes that encode carboxylesterase enzymes include:An approved nomenclature has been established for the five mammalian carboxylesterase gene families.