Catechol-O-methyltransferase

Catechol-O-methyltransferase (COMT; EC 2.1.1.6) is one of several enzymes that degrade catecholamines (neurotransmitters such as dopamine, epinephrine, and norepinephrine), catecholestrogens, and various drugs and substances having a catechol structure.^[7] In humans, catechol-O-methyltransferase protein is encoded by the COMT gene.^[8] Two isoforms of COMT are produced: the soluble short form (S-COMT) and the membrane bound long form (MB-COMT). As the regulation of catecholamines is impaired in a number of medical conditions, several pharmaceutical drugs target COMT to alter its activity and therefore the availability of catecholamines.^[9] COMT was first discovered by the biochemist Julius Axelrod in 1957.^[10]

COMT
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 4XUE, 3A7E, 3BWM, 3BWY, 4PYI, 4PYJ, 4PYK, 4XUC, 4XUD
Identifiers
Aliases	COMT, HEL-S-98n, catechol-O-methyltransferase
External IDs	OMIM: 116790 MGI: 88470 HomoloGene: 30982 GeneCards: COMT
Gene location (Human) Chr. Chromosome 22 (human)^[1] Band 22q11.21 Start 19,941,371 bp^[1] End 19,969,975 bp^[1]
Gene location (Mouse) Chr. Chromosome 16 (mouse)^[2] Band 16 A3|16 11.4 cM Start 18,225,636 bp^[2] End 18,245,602 bp^[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in stromal cell of endometrium left adrenal gland olfactory bulb right lobe of liver corpus callosum renal medulla right lung body of tongue tibial nerve amygdala Top expressed in white adipose tissue proximal tubule liver kidney adrenal gland urinary bladder heart duodenum islet of Langerhans esophagus More reference expression data BioGPS More reference expression data
Gene ontology Molecular function transferase activity O-methyltransferase activity metal ion binding protein binding magnesium ion binding catechol O-methyltransferase activity methyltransferase activity L-dopa O-methyltransferase activity orcinol O-methyltransferase activity Cellular component cytoplasm integral component of membrane cell body cytosol postsynaptic membrane membrane plasma membrane dendritic spine axon dendrite mitochondrion extracellular exosome intracellular membrane-bounded organelle Biological process multicellular organismal reproductive process negative regulation of smooth muscle cell proliferation response to organic cyclic compound regulation of sensory perception of pain estrogen metabolic process cellular response to phosphate starvation catechol-containing compound metabolic process female pregnancy negative regulation of dopamine metabolic process developmental process learning catecholamine metabolic process neurotransmitter catabolic process response to lipopolysaccharide methylation dopamine metabolic process response to pain short-term memory negative regulation of renal sodium excretion dopamine catabolic process positive regulation of homocysteine metabolic process catecholamine catabolic process response to estrogen Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 1312 12846 Ensembl ENSG00000093010 ENSMUSG00000000326 UniProt P21964 O88587 RefSeq (mRNA) NM_000754 NM_001135161 NM_001135162 NM_007310 NM_001362828 NM_001111062 NM_001111063 NM_007744 RefSeq (protein) NP_000745 NP_001128633 NP_001128634 NP_009294 NP_001349757 NP_001104532 NP_001104533 NP_031770 Location (UCSC) Chr 22: 19.94 – 19.97 Mb Chr 16: 18.23 – 18.25 Mb PubMed search ^[3] ^[4]
Wikidata
View/Edit Human View/Edit Mouse

catechol-O-methyltransferase
Identifiers
EC no.	2.1.1.6
CAS no.	9012-25-3
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
Search PMC articles PubMed articles NCBI proteins

Norepinephrine degradation. Catechol-O-methyltransferase is shown in green boxes.^[5][6]

Function

Catechol-O-methyltransferase is involved in the inactivation of the catecholamine neurotransmitters (dopamine, epinephrine, and norepinephrine). The enzyme introduces a methyl group to the catecholamine, which is donated by S-adenosyl methionine (SAM). Any compound having a catechol structure, like catecholestrogens and catechol-containing flavonoids, are substrates of COMT.

Levodopa, a precursor of catecholamines, is an important substrate of COMT. COMT inhibitors, like entacapone, save levodopa from COMT and prolong the action of levodopa.^[11] Entacapone is a widely used adjunct drug of levodopa therapy. When given with an inhibitor of dopa decarboxylase (carbidopa or benserazide), levodopa is optimally saved. This "triple therapy" is becoming a standard in the treatment of Parkinson's disease.

Specific reactions catalyzed by COMT include:

• Dopamine → 3-methoxytyramine
• DOPAC → HVA (homovanillic acid)
• Norepinephrine → normetanephrine
• Epinephrine → metanephrine
• Dihydroxyphenylethylene glycol (DOPEG) → methoxyhydroxyphenylglycol (MOPEG)
• 3,4-Dihydroxymandelic acid (DOMA) → vanillylmandelic acid (VMA)

In the brain, COMT-dependent dopamine degradation is of particular importance in brain regions with low expression of the presynaptic dopamine transporter (DAT), such as the prefrontal cortex.^{[12][13][14][15]} (In the PFC, dopamine is also removed by presynaptic norepinephrine transporters (NET) and degraded by monoamine oxidase.)^[16] Controversy exists about the predominance and orientation of membrane bound COMT in the CNS,^[17][18][19] that is, whether this COMT process is active intracellularly in postsynaptic neurons and glia, or oriented outward on the membrane, acting extracellularly on synaptic and extrasynaptic dopamine.

Soluble COMT can also be found extracellularly, although extracellular COMT plays a less significant role in the CNS than it does peripherally.^[20]: 210 Despite its importance in neurons, COMT is actually primarily expressed in the liver.^[20]: 135

Genetics in humans

The COMT protein is coded by the gene COMT. The gene is associated with allelic variants. The best-studied is Val¹⁵⁸Met.^[15] Others are rs737865 and rs165599 that have been studied, e.g., for association with personality traits,^[21] response to antidepressant medications,^[22] and psychosis risk associated with Alzheimer's disease.^[23] COMT has been studied as a potential gene in the pathogenesis of schizophrenia; however meta-analyses find no association between the risk of schizophrenia and a number of polymorphisms,^[24] including Val¹⁵⁸Met.^[25][26][27]

Val¹⁵⁸Met polymorphism

A functional single-nucleotide polymorphism (a common normal variant) of the gene for catechol-O-methyltransferase results in a valine to methionine mutation at position 158 (Val¹⁵⁸Met) rs4680.^[15] In vitro, the homozygous Val variant metabolizes dopamine at up to four times the rate of its methionine counterpart.^[22] However, in vivo the Met variant is overexpressed in the brain,^[28] resulting in a 40% decrease (rather than 75% decrease) in functional enzyme activity.^[29] The lower rates of catabolism for the Met allele results in higher synaptic dopamine levels following neurotransmitter release, ultimately increasing dopaminergic stimulation of the postsynaptic neuron. Given the preferential role of COMT in prefrontal dopamine degradation, the Val¹⁵⁸Met polymorphism is thought to exert its effects on cognition by modulating dopamine signaling in the frontal lobes.

The gene variant has been shown to affect cognitive tasks broadly related to executive function, such as set shifting, response inhibition, abstract thought, and the acquisition of rules or task structure.^[30][31][32]

Comparable effects on similar cognitive tasks, the frontal lobes, and the neurotransmitter dopamine have also all been linked to schizophrenia.^[33][34] It has been proposed that an inherited variant of COMT is one of the genetic factors that may predispose someone to developing schizophrenia later in life.^[35] A more recent study cast doubt on the proposed connection between this gene and any alleged casual effect of cannabis on schizophrenia development.^[36]

A non-synonymous single-nucleotide polymorphism rs4680 was found to be associated with depressed factor of Positive and Negative Syndrome Scale(PANSS) and efficiency of emotion in schizophrenia subjects.^[37] It is increasingly recognised that allelic variation at the COMT gene are also relevant for emotional processing, as they seem to influence the interaction between prefrontal and limbic regions. Research conducted at the Section of Neurobiology of Psychosis, Institute of Psychiatry, King's College London has demonstrated an effect of COMT both in patients with bipolar disorder and in their relatives,^[38] but these findings have not been replicated so far.

The COMT Val¹⁵⁸Met polymorphism also has a pleiotropic effect on emotional processing.^[38][39] Furthermore, the polymorphism has been shown to affect ratings of subjective well-being. When 621 women were measured with experience sample monitoring, which is similar to mood assessment as response to beeping watch, the met/met form confers double the subjective mental sensation of well-being from a wide variety of daily events. The ability to experience reward increased with the number of Met alleles.^[40] Also, the effect of different genotype was greater for events that were felt as more pleasant. The effect size of genotypic moderation was quite large: Subjects with the Val/Val genotype generated almost similar amounts of subjective well-being from a 'very pleasant event' as Met/Met subjects did from a 'bit pleasant event'. Genetic variation with functional impact on cortical dopamine tone has a strong influence on reward experience in the flow of daily life.^[40] In one study participants with the met/met phenotype described an increase of positive affect twice as high in amplitude as participants with the Val/Val phenotype following very pleasant or pleasant events.^[40]

One review found that those with Val/Val tended to be more extroverted, more novelty-seeking, and less neurotic than those with the Met/Met allele^[41]

Temporomandibular joint dysfunction

Temporomandibular joint dysfunction (TMD) does not appear to be a classic genetic disorder, however variations in the gene that codes for COMT have been suggested to be responsible for inheritance of a predisposition to develop TMD during life.^[42]

Nomenclature

COMT is the name given to the gene that codes for this enzyme. The O in the name stands for oxygen, not for ortho.

COMT inhibitors

COMT inhibitors include entacapone, tolcapone, opicapone, and nitecapone. All except nitecapone are used in the treatment of Parkinson's disease.^[43] Risk of liver toxicity and related digestive disorders restricts the use of tolcapone.^[44]

See also

• Dopamine
• Schizophrenia
• O-methyltransferase

Additional images

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References

1. GRCh38: Ensembl release 89: ENSG00000093010 – Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000000326 – Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Flower R, Rang HP, Dale MM, Ritter JM (2007). "Figure 11-4". Rang & Dale's pharmacology (6th ed.). Edinburgh: Churchill Livingstone. ISBN 978-0-443-06911-6.
6. Rang HP, Dale MM, Ritter JM, Flower RJ, Henderson G (2011). "Figure 14.4". Rang & Dale's Pharmacology. Student consult (7th ed.). Elsevier Health Sciences. ISBN 978-0-7020-4504-2.
7. . mayomedicallaboratories.com. Mayo Clinic: Mayo Medical Laboratories. Archived from the original on September 18, 2008. Retrieved November 16, 2016.
8. Grossman MH, Emanuel BS, Budarf ML (April 1992). "Chromosomal mapping of the human catechol-O-methyltransferase gene to 22q11.1----q11.2". Genomics. 12 (4): 822–825. doi:10.1016/0888-7543(92)90316-K. PMID 1572656.
9. Tai CH, Wu RM (February 2002). "catechol-O-methyltransferase and Parkinson's disease". Acta Medica Okayama. 56 (1): 1–6. doi:10.18926/AMO/31725. PMID 11873938.
10. Axelrod J (August 1957). "O-methylation of epinephrine and other catechols in vitro and in vivo". Science. 126 (3270): 400–401. Bibcode:1957Sci...126..400A. doi:10.1126/science.126.3270.400. PMID 13467217.
11. Ruottinen HM, Rinne UK (November 1998). "COMT inhibition in the treatment of Parkinson's disease". Journal of Neurology. 245 (11 Suppl 3): P25–P34. doi:10.1007/PL00007743. PMID 9808337. S2CID 26793445.
         Goetz CG (May 1998). "Influence of COMT inhibition on levodopa pharmacology and therapy". Neurology. 50 (5 Suppl 5): S26–S30. doi:10.1212/WNL.50.5_Suppl_5.S26. PMID 9591519. S2CID 32448444.
12. Brodal P (2016). "Chapter 5: Neurotransmitters and their receptors". The Central Nervous System. Oxford University Press. p. 75. ISBN 978-0-19-022896-5.
13. Scheggia D, Sannino S, Scattoni ML, Papaleo F (May 2012). "COMT as a drug target for cognitive functions and dysfunctions". CNS & Neurological Disorders Drug Targets. 11 (3): 209–221. doi:10.2174/187152712800672481. PMID 22483296.
14. Diaz-Asper CM, Weinberger DR, Goldberg TE (January 2006). "catechol-O-methyltransferase polymorphisms and some implications for cognitive therapeutics". NeuroRx. 3 (1): 97–105. doi:10.1016/j.nurx.2005.12.010. PMC 3593358. PMID 16490416.
15. Schacht JP (October 2016). "COMT val158met moderation of dopaminergic drug effects on cognitive function: a critical review". The Pharmacogenomics Journal. 16 (5): 430–438. doi:10.1038/tpj.2016.43. PMC 5028240. PMID 27241058.
16. Juarez B, Han MH (September 2016). "Diversity of Dopaminergic Neural Circuits in Response to Drug Exposure". Neuropsychopharmacology. 41 (10): 2424–2446. doi:10.1038/npp.2016.32. PMC 4987841. PMID 26934955.
17. Nissinen E, ed. (2010). Basic Aspects of Catechol-O-Methyltransferase and the Clinical Applications of its Inhibitors. Academic Press. p. 34. ISBN 978-0-12-381327-5 – via Google books.
18. Chen J, Song J, Yuan P, Tian Q, Ji Y, Ren-Patterson R, et al. (October 2011). "Orientation and cellular distribution of membrane-bound catechol-O-methyltransferase in cortical neurons: implications for drug development". The Journal of Biological Chemistry. 286 (40): 34752–34760. doi:10.1074/jbc.M111.262790. PMC 3186432. PMID 21846718. The cellular distribution of MB-COMT in cortical neurons remains unclear and the orientation of MB-COMT on the cellular membrane is controversial.
19. Schott BH, Frischknecht R, Debska-Vielhaber G, John N, Behnisch G, Düzel E, et al. (2010). "Membrane-Bound Catechol-O-Methyl Transferase in Cortical Neurons and Glial Cells is Intracellularly Oriented". Frontiers in Psychiatry. 1: 142. doi:10.3389/fpsyt.2010.00142. PMC 3059651. PMID 21423451. It has been a matter of debate whether in neural cells of the CNS the enzymatic domain of MB-COMT is oriented toward the cytoplasmic or the extracellular compartment.
20. Golan DE, Tashjian AH (2011-12-15). Principles of pharmacology (3rd ed.). Philadelphia: Wolters Kluwer Health. ISBN 978-1-60831-270-2. OCLC 705260923.
21. Gold MS, Blum K, Oscar-Berman M, Braverman ER (January 2014). "Low dopamine function in attention deficit/hyperactivity disorder: should genotyping signify early diagnosis in children?". Postgraduate Medicine. 126 (1): 153–177. doi:10.3810/pgm.2014.01.2735. PMC 4074363. PMID 24393762.
22. Porcelli S, Drago A, Fabbri C, Gibiino S, Calati R, Serretti A (March 2011). "Pharmacogenetics of antidepressant response". Journal of Psychiatry & Neuroscience. 36 (2): 87–113. doi:10.1503/jpn.100059. PMC 3044192. PMID 21172166.
23. DeMichele-Sweet MA, Sweet RA (2010). "Genetics of psychosis in Alzheimer's disease: a review". Journal of Alzheimer's Disease. 19 (3): 761–780. doi:10.3233/JAD-2010-1274. PMC 2942073. PMID 20157235.
24. Okochi T, Ikeda M, Kishi T, Kawashima K, Kinoshita Y, Kitajima T, et al. (May 2009). "Meta-analysis of association between genetic variants in COMT and schizophrenia: an update". Schizophrenia Research. 110 (1–3): 140–148. doi:10.1016/j.schres.2009.02.019. PMID 19329282. S2CID 22875066.
25. Glatt SJ, Faraone SV, Tsuang MT (March 2003). "Association between a functional catechol O-methyltransferase gene polymorphism and schizophrenia: meta-analysis of case-control and family-based studies". The American Journal of Psychiatry. 160 (3): 469–476. doi:10.1176/appi.ajp.160.3.469. PMID 12611827. S2CID 25352000.
26. Munafò MR, Bowes L, Clark TG, Flint J (August 2005). "Lack of association of the COMT (Val158/108 Met) gene and schizophrenia: a meta-analysis of case-control studies". Molecular Psychiatry. 10 (8): 765–770. doi:10.1038/sj.mp.4001664. PMID 15824744.
27. Fan JB, Zhang CS, Gu NF, Li XW, Sun WW, Wang HY, et al. (January 2005). "catechol-O-methyltransferase gene Val/Met functional polymorphism and risk of schizophrenia: a large-scale association study plus meta-analysis". Biological Psychiatry. 57 (2): 139–144. doi:10.1016/j.biopsych.2004.10.018. PMID 15652872. S2CID 23416733.
28. Zhu G, Lipsky RH, Xu K, Ali S, Hyde T, Kleinman J, et al. (December 2004). "Differential expression of human COMT alleles in brain and lymphoblasts detected by RT-coupled 5' nuclease assay". Psychopharmacology. 177 (1–2): 178–184. doi:10.1007/s00213-004-1938-z. PMID 15290009. S2CID 33013401.
29. Chen J, Lipska BK, Halim N, Ma QD, Matsumoto M, Melhem S, et al. (November 2004). "Functional analysis of genetic variation in catechol-O-methyltransferase (COMT): effects on mRNA, protein, and enzyme activity in postmortem human brain". American Journal of Human Genetics. 75 (5): 807–821. doi:10.1086/425589. PMC 1182110. PMID 15457404.
30. Bruder GE, Keilp JG, Xu H, Shikhman M, Schori E, Gorman JM, Gilliam TC (December 2005). "catechol-O-methyltransferase (COMT) genotypes and working memory: associations with differing cognitive operations". Biological Psychiatry. 58 (11): 901–907. doi:10.1016/j.biopsych.2005.05.010. PMID 16043133. S2CID 17902043.
31. Robinson S, Goddard L, Dritschel B, Wisley M, Howlin P (December 2009). "Executive functions in children with autism spectrum disorders". Brain and Cognition. 71 (3): 362–368. doi:10.1016/j.bandc.2009.06.007. PMID 19628325. S2CID 14587250.
32. Diamond A, Briand L, Fossella J, Gehlbach L (January 2004). "Genetic and neurochemical modulation of prefrontal cognitive functions in children". The American Journal of Psychiatry. 161 (1): 125–132. doi:10.1176/appi.ajp.161.1.125. PMID 14702260. S2CID 2341627.
33. . NIH Record. LVII (20): 3. 7 October 2005. Archived from the original on 22 May 2015.
34. "The Runners-Up". Science. 302 (5653): 2039–2045. 2003. doi:10.1126/science.302.5653.2039. S2CID 220088635.
35. Caspi A, Moffitt TE, Cannon M, McClay J, Murray R, Harrington H, et al. (May 2005). "Moderation of the effect of adolescent-onset cannabis use on adult psychosis by a functional polymorphism in the catechol-O-methyltransferase gene: longitudinal evidence of a gene X environment interaction". Biological Psychiatry. 57 (10): 1117–1127. doi:10.1016/j.biopsych.2005.01.026. PMID 15866551. S2CID 39405111.
36. Zammit S, Spurlock G, Williams H, Norton N, Williams N, O'Donovan MC, Owen MJ (November 2007). "Genotype effects of CHRNA7, CNR1 and COMT in schizophrenia: interactions with tobacco and cannabis use". The British Journal of Psychiatry. 191 (5): 402–407. doi:10.1192/bjp.bp.107.036129. PMID 17978319.
    • Davenport L (16 November 2007). . MedWireNews. Archived from the original on 5 November 2012. Retrieved 5 July 2010.
37. Punchaichira TJ, Kukshal P, Bhatia T, Deshpande SN, Thelma BK (October 2020). "The effect of rs1076560 (DRD2) and rs4680 (COMT) on tardive dyskinesia and cognition in schizophrenia subjects". Psychiatric Genetics. 30 (5): 125–135. doi:10.1097/YPG.0000000000000258. PMC 10111058. PMID 32931693. S2CID 221718209.
38. Lelli-Chiesa G, Kempton MJ, Jogia J, Tatarelli R, Girardi P, Powell J, et al. (April 2011). "The impact of the Val158Met catechol-O-methyltransferase genotype on neural correlates of sad facial affect processing in patients with bipolar disorder and their relatives" (PDF). Psychological Medicine. 41 (4): 779–788. doi:10.1017/S0033291710001431. PMID 20667170. S2CID 206251638.
39. Kempton MJ, Haldane M, Jogia J, Christodoulou T, Powell J, Collier D, et al. (April 2009). "The effects of gender and COMT Val158Met polymorphism on fearful facial affect recognition: a fMRI study". The International Journal of Neuropsychopharmacology. 12 (3): 371–381. doi:10.1017/S1461145708009395. PMID 18796186.
40. Wichers M, Aguilera M, Kenis G, Krabbendam L, Myin-Germeys I, Jacobs N, et al. (December 2008). "The catechol-O-methyl transferase Val158Met polymorphism and experience of reward in the flow of daily life". Neuropsychopharmacology. 33 (13): 3030–3036. doi:10.1038/sj.npp.1301520. PMID 17687265.
41. Montag C, Jurkiewicz M, Reuter M (May 2012). "The role of the catechol-O-methyltransferase (COMT) gene in personality and related psychopathological disorders". CNS & Neurological Disorders Drug Targets. 11 (3): 236–250. doi:10.2174/187152712800672382. PMC 4345409. PMID 22483293.
42. Cairns BE (May 2010). "Pathophysiology of TMD pain--basic mechanisms and their implications for pharmacotherapy". Journal of Oral Rehabilitation. 37 (6): 391–410. doi:10.1111/j.1365-2842.2010.02074.x. PMID 20337865.
43. Bonifácio MJ, Palma PN, Almeida L, Soares-da-Silva P (2007). "catechol-O-methyltransferase and its inhibitors in Parkinson's disease". CNS Drug Reviews. 13 (3): 352–379. doi:10.1111/j.1527-3458.2007.00020.x. PMC 6494163. PMID 17894650.
44. Jatana N, Apoorva N, Malik S, Sharma A, Latha N (January 2013). "Inhibitors of catechol-O-methyltransferase in the treatment of neurological disorders". Central Nervous System Agents in Medicinal Chemistry. 13 (3): 166–194. doi:10.2174/1871524913666140109113341. PMID 24450388. Two of the nitrocatechols, entacapone ... and tolcapone ... have been demonstrated to reduce the dose of L-DOPA required and also cause improvement in clinical symptoms, although tolcapone emerged to be more efficacious due to its greater bioavailability and a longer half-life when compared to entacapone. However, tolcapone is clinically restricted owing to its increased hepatotoxicity and other related digestive disorders.

Further reading

• Trendelenburg U (1991). "The interaction of transport mechanisms and intracellular enzymes in metabolizing systems". Amine Oxidases and Their Impact on Neurobiology. Vol. 32. pp. 3–18. doi:10.1007/978-3-7091-9113-2_1. ISBN 978-3-211-82239-5. PMID 2089098. {{cite book}}: |journal= ignored (help)
• Zhu BT (October 2002). "On the mechanism of homocysteine pathophysiology and pathogenesis: a unifying hypothesis". Histology and Histopathology. 17 (4): 1283–1291. doi:10.14670/HH-17.1283. PMID 12371153.
• Oroszi G, Goldman D (December 2004). "Alcoholism: genes and mechanisms". Pharmacogenomics. 5 (8): 1037–1048. doi:10.1517/14622416.5.8.1037. PMID 15584875.
• Fan JB, Zhang CS, Gu NF, Li XW, Sun WW, Wang HY, et al. (January 2005). "catechol-O-methyltransferase gene Val/Met functional polymorphism and risk of schizophrenia: a large-scale association study plus meta-analysis". Biological Psychiatry. 57 (2): 139–144. doi:10.1016/j.biopsych.2004.10.018. PMID 15652872. S2CID 23416733.
• Tunbridge EM, Harrison PJ, Weinberger DR (July 2006). "Catechol-O-methyltransferase, cognition, and psychosis: Val¹⁵⁸Met and beyond". Biological Psychiatry. 60 (2): 141–151. doi:10.1016/j.biopsych.2005.10.024. PMID 16476412. S2CID 45705154.
• Craddock N, Owen MJ, O'Donovan MC (May 2006). "The catechol-O-methyl transferase (COMT) gene as a candidate for psychiatric phenotypes: evidence and lessons". Molecular Psychiatry. 11 (5): 446–458. doi:10.1038/sj.mp.4001808. PMID 16505837.
• Frank MJ, Moustafa AA, Haughey HM, Curran T, Hutchison KE (October 2007). "Genetic triple dissociation reveals multiple roles for dopamine in reinforcement learning". Proceedings of the National Academy of Sciences of the United States of America. 104 (41): 16311–16316. Bibcode:2007PNAS..10416311F. doi:10.1073/pnas.0706111104. PMC 2042203. PMID 17913879.
• Greenberg, Gary (November 7, 2018). "What If the Placebo Effect Isn't a Trick?". New York Times Magazine.

External links

 

Wikimedia Commons has media related to Catechol O-methyltransferase, COMT.

• Catechol+O-Methyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• Overview of all the structural information available in the PDB for UniProt: P21964 (Human Catechol O-methyltransferase) at the PDBe-KB.