Biology:Carboxylesterase
| carboxylesterase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC number | 3.1.1.1 | ||||||||
| CAS number | 9016-18-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
The enzyme carboxylesterase (or carboxylic-ester hydrolase, EC 3.1.1.1; systematic name carboxylic-ester hydrolase) catalyzes reactions of the following form:[1]
- a carboxylic ester + H2O [math]\displaystyle{ \rightleftharpoons }[/math] an alcohol + a carboxylate
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 (PDB: 1ci8).
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 (AA C20H32O2; 20:4, n-6), formed by the synthesis from dietary linoleic acid (LA: C18H32O2 18:2, n-6), has a role as a human carboxylesterase inhibitor.[2]
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.
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
The last enzyme also participates in alkaloid biosynthesis.
Genes
Humans genes that encode carboxylesterase enzymes include:
An approved nomenclature has been established for the five mammalian carboxylesterase gene families.[3]
References
- ↑ Aranda, Juan; Cerqueira, N. M. F. S. A.; Fernandes, P.A.; Roca, M.; Tuñon, I.; Ramos, M. J. (2014). "The Catalytic Mechanism of Carboxylesterases. A Computational Study.". Biochemistry 53 (36): 5820–5829. doi:10.1021/bi500934j. PMID 25101647.
- ↑ PubChem. "Arachidonic acid" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/444899.
- ↑ "Recommended nomenclature for five mammalian carboxylesterase gene families: human, mouse, and rat genes and proteins". Mamm. Genome 21 (9–10): 427–41. 2010. doi:10.1007/s00335-010-9284-4. PMID 20931200.
Further reading
- "On the homology of the active-site peptides of liver carboxylesterases". Biochim. Biophys. Acta 171 (1): 128–37. 1969. doi:10.1016/0005-2744(69)90112-0. PMID 4884138.
- "Pig liver esterase. Physical properties". Biochemistry 8 (10): 3879–89. 1969. doi:10.1021/bi00838a001. PMID 4981346.
- "Hydrolysis of vitamin A acetate by unspecific carboxylesterases from liver and kidney". Eur. J. Biochem. 11 (1): 122–6. 1969. doi:10.1111/j.1432-1033.1969.tb00748.x. PMID 5353595.
- BURCH J (1954). "The purification and properties of horse liver esterase". Biochem. J. 58 (3): 415–26. doi:10.1042/bj0580415. PMID 13208632.
- "Carboxylesterases (EC 3.1.1). A large-scale purification of pig liver carboxylesterase". Biochemistry 8 (5): 2000–6. 1969. doi:10.1021/bi00833a033. PMID 5785220.
- "Specificity of goat intestinal esterase". Biochem. Z. 346: 386–402. 1966.
- "Comparative chemical and immunological characterization of five lipolytic enzymes (carboxylesterases) from rat liver microsomes". Arch. Biochem. Biophys. 234 (2): 612–21. 1984. doi:10.1016/0003-9861(84)90311-4. PMID 6208846.
- "Carboxylesterases (EC 3.1.1). Purification and titration of ox liver carboxylesterase". Biochemistry 8 (5): 2013–8. 1969. doi:10.1021/bi00833a035. PMID 5785222.
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