The enzymecarboxylesterase (or carboxylic-ester hydrolase, EC 3.1.1.1; systematic name carboxylic-ester hydrolase) catalyzes reactions of the following form:[1]
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]
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. PMID25101647.
Augusteyn RC, de Jersey J, Webb EC, Zerner B (1969). "On the homology of the active-site peptides of liver carboxylesterases". Biochim. Biophys. Acta. 171 (1): 128–37. doi:10.1016/0005-2744(69)90112-0. PMID4884138.
Horgan DJ, Stoops JK, Webb EC, Zerner B (1969). "Carboxylesterases (EC 3.1.1). A large-scale purification of pig liver carboxylesterase". Biochemistry. 8 (5): 2000–6. doi:10.1021/bi00833a033. PMID5785220.
Malhotra OP, Philip G (1966). "Specificity of goat intestinal esterase". Biochem. Z. 346: 386–402.
Mentlein R, Schumann M, Heymann E (1984). "Comparative chemical and immunological characterization of five lipolytic enzymes (carboxylesterases) from rat liver microsomes". Arch. Biochem. Biophys. 234 (2): 612–21. doi:10.1016/0003-9861(84)90311-4. PMID6208846.
Runnegar MT, Scott K, Webb EC, Zerner B (1969). "Carboxylesterases (EC 3.1.1). Purification and titration of ox liver carboxylesterase". Biochemistry. 8 (5): 2013–8. doi:10.1021/bi00833a035. PMID5785222.