Liver carboxylesterase 1 also known as carboxylesterase 1 (CES1, hCE-1 or CES1A1) is an enzyme that in humans is encoded by the CES1gene.[5][6] The protein is also historically known as serineesterase 1 (SES1), monocyte esterase and cholesterol esterhydrolase (CEH). Three transcript variants encoding three different isoforms have been found for this gene.[6] The various protein products from isoform a, b and c range in size from 568, 567 and 566 amino acids long, respectively.
CES1 is present in most tissues with higher levels in the liver and low levels in the gastrointestinal tract.[7]
Carboxylesterase 1 is a serine esterase and member of a large multigene carboxylesterase family. It is also part of the alpha/beta fold hydrolase family.[7] These enzymes are responsible for the hydrolysis of ester- and amide-bond-containing xenobiotics and drugs such as cocaine and heroin. They also hydrolyze long-chain fatty acid esters and thioesters. As part of phase II metabolism, the resulting carboxylates are then often conjugated by other enzymes to increase solubility and eventually excreted.
This enzyme is known to hydrolyze aromatic and aliphatic esters and can manage cellular cholesterol esterification levels. It may also play a role in detoxification in the lung and/or protection of the central nervous system from ester or amide compounds.[6]
The protein contains an amino acid sequence at its N-terminus that sends it into the endoplasmic reticulum where a C-terminal sequence can bind to a KDEL receptor.[7]
Clinical significance[]
Carboxylesterase 1 deficiency may be associated with non-Hodgkin lymphoma or B-cell lymphocytic leukemia. Inhibition of CES1 by in particular organophosphates reduces tumor-killing activity by monocytes.[8][9] The loss of this protein in monocytes is one product of organophosphate poisoning.[9]
CES1 can activate or deactivate various drugs. CES1 is responsible for the activation of many prodrugs such as angiotensin-converting enzyme (ACE) inhibitors, oseltamivir, and dabigatran.[10][11][12][13] Genetic variants of CES1 can significantly affect both pharmaocokinetics and pharmacodynamics of drugs metabolized by CES1, such as methylphenidate and clopidogrel.[14] The ability of CES1 to metabolize heroin and cocaine among other drugs has suggested a therapeutic role for the enzyme.[15]
Interactive pathway map[]
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
^ abcImai T (Jun 2006). "Human Carboxylesterase Isozymes: Catalytic Properties and Rational Drug Design". Drug Metabolism and Pharmacokinetics. 21 (3): 173–185. doi:10.2133/dmpk.21.173. PMID16858120.
^Oertel J, Hagner G, Kastner M, Huhn D (Dec 1985). "The relevance of alpha-naphthyl acetate esterases to various monocyte functions". Br J Haematol. 61 (4): 717–26. doi:10.1111/j.1365-2141.1985.tb02886.x. PMID4084460. S2CID84899499.
^ abMarkey GM (Feb 2011). "Carboxylesterase 1 (Ces1): from monocyte marker to major player". J Clin Pathol. 64 (2): 107–9. doi:10.1136/jcp.2010.084657. PMID21177752. S2CID32622794.
^Zhu HJ, Appel DI, Johnson JA, Chavin KD, Markowitz JS (Jan 2009). "Role of carboxylesterase 1 and impact of natural genetic variants on the hydrolysis of trandolapril". Biochem Pharmacol. 77 (7): 1266–72. doi:10.1016/j.bcp.2008.12.017. PMID19185566.
^Thomsen R, Rasmussen HB, Linnet K, INDICES Consortium (Jan 2014). "In vitro drug metabolism by human carboxylesterase 1: focus on angiotensin-converting enzyme inhibitors". Drug Metab Dispos. 42 (1): 126–33. doi:10.1124/dmd.113.053512. PMID24141856. S2CID206496779.
^Zhu HJ, Markowitz JS (Feb 2009). "Activation of the antiviral prodrug oseltamivir is impaired by two newly identified carboxylesterase 1 variants". Drug Metab Dispos. 37 (2): 264–7. doi:10.1124/dmd.108.024943. PMID19022936. S2CID9277216.
^Redinbo MR, Bencharit S, Potter PM (Jun 2003). "Human carboxylesterase 1: from drug metabolism to drug discovery". Biochem Soc Trans. 31 (Pt 3): 620–4. doi:10.1042/bst0310620. PMID12773168.
Further reading[]
Riddles PW, Richards LJ, Bowles MR, Pond SM (1992). "Cloning and analysis of a cDNA encoding a human liver carboxylesterase". Gene. 108 (2): 289–92. doi:10.1016/0378-1119(91)90448-K. PMID1748313.
Ketterman AJ, Bowles MR, Pond SM (1990). "Purification and characterization of two human liver carboxylesterases". Int. J. Biochem. 21 (12): 1303–12. doi:10.1016/0020-711X(89)90149-3. PMID2612723.
Kroetz DL, McBride OW, Gonzalez FJ (1993). "Glycosylation-dependent activity of baculovirus-expressed human liver carboxylesterases: cDNA cloning and characterization of two highly similar enzyme forms". Biochemistry. 32 (43): 11606–17. doi:10.1021/bi00094a018. PMID8218228.
Shibata F, Takagi Y, Kitajima M, et al. (1993). "Molecular cloning and characterization of a human carboxylesterase gene". Genomics. 17 (1): 76–82. doi:10.1006/geno.1993.1285. PMID8406473.
Langmann T, Becker A, Aslanidis C, et al. (1997). "Structural organization and characterization of the promoter region of a human carboxylesterase gene". Biochim. Biophys. Acta. 1350 (1): 65–74. doi:10.1016/S0167-4781(96)00142-X. PMID9003459.
Brzezinski MR, Spink BJ, Dean RA, et al. (1997). "Human liver carboxylesterase hCE-1: binding specificity for cocaine, heroin, and their metabolites and analogs". Drug Metab. Dispos. 25 (9): 1089–96. PMID9311626.
Yan B, Matoney L, Yang D (1999). "Human carboxylesterases in term placentae: enzymatic characterization, molecular cloning and evidence for the existence of multiple forms". Placenta. 20 (7): 599–607. doi:10.1053/plac.1999.0407. PMID10452915.
Islam MR, Waheed A, Shah GN, et al. (1999). "Human egasyn binds beta-glucuronidase but neither the esterase active site of egasyn nor the C terminus of beta-glucuronidase is involved in their interaction". Arch. Biochem. Biophys. 372 (1): 53–61. doi:10.1006/abbi.1999.1449. PMID10562416.
Ghosh S (2001). "Cholesteryl ester hydrolase in human monocyte/macrophage: cloning, sequencing, and expression of full-length cDNA". Physiol. Genomics. 2 (1): 1–8. doi:10.1152/physiolgenomics.2000.2.1.1. PMID11015575.
Ghosh S, Natarajan R (2001). "Cloning of the human cholesteryl ester hydrolase promoter: identification of functional peroxisomal proliferator-activated receptor responsive elements". Biochem. Biophys. Res. Commun. 284 (4): 1065–70. doi:10.1006/bbrc.2001.5078. PMID11409902.
Alam M, Ho S, Vance DE, Lehner R (2002). "Heterologous expression, purification, and characterization of human triacylglycerol hydrolase". Protein Expr. Purif. 24 (1): 33–42. doi:10.1006/prep.2001.1553. PMID11812220.
Satoh T, Taylor P, Bosron WF, et al. (2002). "Current progress on esterases: from molecular structure to function". Drug Metab. Dispos. 30 (5): 488–93. doi:10.1124/dmd.30.5.488. PMID11950776.
Alam M, Vance DE, Lehner R (2002). "Structure-function analysis of human triacylglycerol hydrolase by site-directed mutagenesis: identification of the catalytic triad and a glycosylation site". Biochemistry. 41 (21): 6679–87. doi:10.1021/bi0255625. PMID12022871.
Bencharit S, Morton CL, Xue Y, et al. (2003). "Structural basis of heroin and cocaine metabolism by a promiscuous human drug-processing enzyme". Nat. Struct. Biol. 10 (5): 349–56. doi:10.1038/nsb919. PMID12679808. S2CID1108060.