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Record Information
Version3.6
Creation Date2005-11-16 15:48:42 UTC
Update Date2013-04-14 22:29:59 UTC
HMDB IDHMDB00062
Secondary Accession Numbers
  • HMDB01467
Metabolite Identification
Common NameL-Carnitine
DescriptionCarnitine is not an essential amino acid; it can be synthesized in the body. However, it is so important in providing energy to muscles including the heart-that some researchers are now recommending carnitine supplements in the diet, particularly for people who do not consume much red meat, the main food source for carnitine. Carnitine has been described as a vitamin, an amino acid, or a metabimin, i.e., an essential metabolite. Like the B vitamins, carnitine contains nitrogen and is very soluble in water, and to some researchers carnitine is a vitamin (Liebovitz 1984). It was found that an animal (yellow mealworm) could not grow without carnitine in its diet. However, as it turned out, almost all other animals, including humans, do make their own carnitine; thus, it is no longer considered a vitamin. Nevertheless, in certain circumstances-such as deficiencies of methionine, lysine or vitamin C or kidney dialysis--carnitine shortages develop. Under these conditions, carnitine must be absorbed from food, and for this reason it is sometimes referred to as a "metabimin" or a conditionally essential metabolite. Like the other amino acids used or manufactured by the body, carnitine is an amine. But like choline, which is sometimes considered to be a B vitamin, carnitine is also an alcohol (specifically, a trimethylated carboxy-alcohol). Thus, carnitine is an unusual amino acid and has different functions than most other amino acids, which are most usually employed by the body in the construction of protein. Carnitine is an essential factor in fatty acid metabolism in mammals. It's most important known metabolic function is to transport fat into the mitochondria of muscle cells, including those in the heart, for oxidation. This is how the heart gets most of its energy. In humans, about 25% of carnitine is synthesized in the liver, kidney and brain from the amino acids lysine and methionine. Most of the carnitine in the body comes from dietary sources such as red meat and dairy products. Inborn errors of carnitine metabolism can lead to brain deterioration like that of Reye's syndrome, gradually worsening muscle weakness, Duchenne-like muscular dystrophy and extreme muscle weakness with fat accumulation in muscles. Borurn et al. (1979) describe carnitine as an essential nutrient for pre-term babies, certain types (non-ketotic) of hypoglycemics, kidney dialysis patients, cirrhosis, and in kwashiorkor, type IV hyperlipidemia, heart muscle disease (cardiomyopathy), and propionic or organic aciduria (acid urine resulting from genetic or other anomalies). In all these conditions and the inborn errors of carnitine metabolism, carnitine is essential to life and carnitine supplements are valuable. carnitine therapy may also be useful in a wide variety of clinical conditions. carnitine supplementation has improved some patients who have angina secondary to coronary artery disease. It may be worth a trial in any form of hyperlipidemia or muscle weakness. carnitine supplements may be useful in many forms of toxic or metabolic liver disease and in cases of heart muscle disease. Hearts undergoing severe arrhythmia quickly deplete their stores of carnitine. Athletes, particularly in Europe, have used carnitine supplements for improved endurance. carnitine may improve muscle building by improving fat utilization and may even be useful in treating obesity. carnitine joins a long list of nutrients which may be of value in treating pregnant women, hypothyroid individuals, and male infertility due to low motility of sperm. Even the Physician's Desk Reference gives indication for carnitine supplements as "improving the tolerance of ischemic heart disease, myocardial insufficiencies, and type IV hyperlipoproteinemia. carnitine deficiency is noted in abnormal liver function, renal dialysis patients, and severe to moderate muscular weakness with associated anorexia." (http://www.dcnutrition.com).
Structure
Thumb
Synonyms
  1. (-)-(R)-3-Hydroxy-4-(trimethylammonio)butyrate
  2. (-)-carnitine
  3. (R)-(3-Carboxy-2-hydroxypropyl)trimethylammonium hydroxide
  4. (R)-carnitine
  5. (S)-carnitine
  6. 1-Carnitine
  7. 3-Carboxy-2-hydroxy-N,N,N-trimethyl-1-propanaminium
  8. 3-Hydroxy-4-trimethylammoniobutanoate
  9. 3-Hydroxy-4-trimethylammoniobutanoic acid
  10. Bicarnesine
  11. Carniking
  12. Carniking 50
  13. Carnilean
  14. Carnipass
  15. Carnipass 20
  16. Carnitene
  17. Carnitine
  18. Carnitor
  19. D-Carnitine
  20. delta-Carnitine
  21. DL-carnitine
  22. gamma-Trimethyl-ammonium-beta-hydroxybutirate
  23. gamma-Trimethyl-beta-hydroxybutyrobetaine
  24. gamma-Trimethyl-hydroxybutyrobetaine
  25. Karnitin
  26. L-(-)-Carnitine
  27. L-Carnitine
  28. L-gamma-Trimethyl-beta-hydroxybutyrobetaine
  29. Levocarnitina
  30. Levocarnitine
  31. Levocarnitinum
  32. R-(-)-3-Hydroxy-4-trimethylaminobutyrate
  33. Vitamin BT
Chemical FormulaC7H15NO3
Average Molecular Weight161.1989
Monoisotopic Molecular Weight161.105193351
IUPAC Name(3R)-3-hydroxy-4-(trimethylazaniumyl)butanoate
Traditional IUPAC NameL-carnitine
CAS Registry Number541-15-1
SMILES
C[N+](C)(C)C[C@H](O)CC([O-])=O
InChI Identifier
InChI=1S/C7H15NO3/c1-8(2,3)5-6(9)4-7(10)11/h6,9H,4-5H2,1-3H3/t6-/m1/s1
InChI KeyPHIQHXFUZVPYII-ZCFIWIBFSA-N
Chemical Taxonomy
KingdomOrganic Compounds
Super ClassAliphatic Acyclic Compounds
ClassAlkylamines
Sub ClassQuaternary Ammonium Salts
Other Descriptors
  • Aliphatic Acyclic Compounds
  • a D,L-carnitine(Cyc)
  • amino-acid betaine(ChEBI)
  • gamma-amino acid(ChEBI)
Substituents
  • Beta Hydroxy Acid
  • Carboxylic Acid Salt
  • Choline
  • Secondary Alcohol
Direct ParentCarnitines
Ontology
StatusDetected and Quantified
Origin
  • Endogenous
Biofunction
  • Component of Alanine and aspartate metabolism
  • Component of Fatty acid metabolism
  • Essential amino acid
ApplicationNot Available
Cellular locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Endoplasmic reticulum
  • Peroxisome
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point197 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
Water Solubility5.33 g/LALOGPS
logP-2.9ALOGPS
logP-4.9ChemAxon
logS-1.6ALOGPS
pKa (Strongest Acidic)4.2ChemAxon
pKa (Strongest Basic)-3.6ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area60.36ChemAxon
Rotatable Bond Count4ChemAxon
Refractivity63.49ChemAxon
Polarizability16.9ChemAxon
Spectra
SpectraNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Endoplasmic reticulum
  • Peroxisome
Biofluid Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Urine
Tissue Location
  • Adipose Tissue
  • Bladder
  • Brain
  • Erythrocyte
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Lung
  • Muscle
  • Myocardium
  • Nerve Cells
  • Neuron
  • Platelet
  • Prostate
  • Skeletal Muscle
  • Sperm
  • Testes
Pathways
NameSMPDB LinkKEGG Link
Beta Oxidation of Very Long Chain Fatty AcidsSMP00052map01040
Carnitine SynthesisSMP00465Not Available
Mitochondrial Beta-Oxidation of Long Chain Saturated Fatty AcidsSMP00482Not Available
Mitochondrial Beta-Oxidation of Short Chain Saturated Fatty AcidsSMP00480Not Available
Oxidation of Branched Chain Fatty AcidsSMP00030Not Available
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified29.74 +/- 7.55 uMAdult (>18 years old)Not SpecifiedNormal details
BloodDetected and Quantified33.6 +/- 6.2 uMChildren (1-13 years old)BothNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified38.2 +/- 5.4 uMAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified43.0 (26.0-79.0) uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified45.7 +/- 11.6 uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified1.900 +/- 0.474 uMAdult (>18 years old)BothNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified4.0 (2.0 - 9.0) uMAdult (>18 years old)BothNormal details
UrineDetected but not QuantifiedNot ApplicableAdult (>18 years old)MaleNormal details
UrineDetected but not QuantifiedNot ApplicableAdult (>18 years old)BothNormal details
UrineDetected and Quantified4.5 (0.62-15.2) umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified5.0 (0.7-16.4) umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified3.17 umol/mmol creatinineAdult (>18 years old)MaleNormal
    • Shaykhutdinov RA,...
details
UrineDetected and Quantified5.7 +/- 4.8 umol/mmol creatinineAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
details
UrineDetected and Quantified23.5 +/- 4.0 umol/mmol creatinineAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
details
UrineDetected and Quantified18.0 +/- 1.2 umol/mmol creatinineAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
details
Abnormal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified41.7 +/- 23.9 uMAdult (>18 years old)Not SpecifiedHeart Transplant details
UrineDetected and Quantified13.3 (11.6-15.1) umol/mmol creatinineAdult (>18 years old)Both
Diabetes
details
UrineDetected and Quantified41.3 (38.3-44.2) umol/mmol creatinineAdult (>18 years old)Both
Diabetes
details
UrineDetected and Quantified7.0 (0.0-30.0) umol/mmol creatinineNot SpecifiedBothLung cancer details
Associated Disorders and Diseases
Disease References
Diabetes mellitus type 2
  1. Hoppel CL, Genuth SM: Urinary excretion of acetylcarnitine during human diabetic and fasting ketosis. Am J Physiol. 1982 Aug;243(2):E168-72. Pubmed: 6810706
Lung Cancer
  1. Wishart DS, Knox C, Guo AC, Eisner R, Young N, Gautam B, Hau DD, Psychogios N, Dong E, Bouatra S, Mandal R, Sinelnikov I, Xia J, Jia L, Cruz JA, Lim E, Sobsey CA, Shrivastava S, Huang P, Liu P, Fang L, Peng J, Fradette R, Cheng D, Tzur D, Clements M, Lewis A, De Souza A, Zuniga A, Dawe M, Xiong Y, Clive D, Greiner R, Nazyrova A, Shaykhutdinov R, Li L, Vogel HJ, Forsythe I: HMDB: a knowledgebase for the human metabolome. Nucleic Acids Res. 2008 Oct 25. Pubmed: 18953024
Associated OMIM IDs
DrugBank IDDB00583
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB000572
KNApSAcK IDNot Available
Chemspider ID2006614
KEGG Compound IDC00318
BioCyc IDCARNITINE
BiGG ID34600
Wikipedia LinkL-Carnitine
NuGOwiki LinkHMDB00062
Metagene LinkHMDB00062
METLIN ID52
PubChem Compound2724480
PDB ID1NDF
ChEBI ID11060
References
Synthesis Reference Bols, Mikael; Lundt, Inge; Pedersen, Christian. Simple synthesis of (R)-carnitine from D-galactono-1,4-lactone. Tetrahedron (1992), 48(2), 319-24.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Tamai I, China K, Sai Y, Kobayashi D, Nezu J, Kawahara E, Tsuji A: Na(+)-coupled transport of L-carnitine via high-affinity carnitine transporter OCTN2 and its subcellular localization in kidney. Biochim Biophys Acta. 2001 Jun 6;1512(2):273-84. Pubmed: 11406104
  2. Waldner R, Laschan C, Lohninger A, Gessner M, Tuchler H, Huemer M, Spiegel W, Karlic H: Effects of doxorubicin-containing chemotherapy and a combination with L-carnitine on oxidative metabolism in patients with non-Hodgkin lymphoma. J Cancer Res Clin Oncol. 2006 Feb;132(2):121-8. Epub 2005 Nov 8. Pubmed: 16283381
  3. Sreekumar A, Poisson LM, Rajendiran TM, Khan AP, Cao Q, Yu J, Laxman B, Mehra R, Lonigro RJ, Li Y, Nyati MK, Ahsan A, Kalyana-Sundaram S, Han B, Cao X, Byun J, Omenn GS, Ghosh D, Pennathur S, Alexander DC, Berger A, Shuster JR, Wei JT, Varambally S, Beecher C, Chinnaiyan AM: Metabolomic profiles delineate potential role for sarcosine in prostate cancer progression. Nature. 2009 Feb 12;457(7231):910-4. Pubmed: 19212411
  4. Wachter S, Vogt M, Kreis R, Boesch C, Bigler P, Hoppeler H, Krahenbuhl S: Long-term administration of L-carnitine to humans: effect on skeletal muscle carnitine content and physical performance. Clin Chim Acta. 2002 Apr;318(1-2):51-61. Pubmed: 11880112
  5. Evans AM, Fornasini G: Pharmacokinetics of L-carnitine. Clin Pharmacokinet. 2003;42(11):941-67. Pubmed: 12908852
  6. Pastoris O, Dossena M, Foppa P, Catapano M, Arbustini E, Bellini O, Dal Bello B, Minzioni G, Ceriana P, Barzaghi N: Effect of L-carnitine on myocardial metabolism: results of a balanced, placebo-controlled, double-blind study in patients undergoing open heart surgery. Pharmacol Res. 1998 Feb;37(2):115-22. Pubmed: 9572066
  7. Stephens FB, Constantin-Teodosiu D, Laithwaite D, Simpson EJ, Greenhaff PL: Insulin stimulates L-carnitine accumulation in human skeletal muscle. FASEB J. 2006 Feb;20(2):377-9. Epub 2005 Dec 20. Pubmed: 16368715
  8. Malaguarnera M, Pistone G, Astuto M, Dell'Arte S, Finocchiaro G, Lo Giudice E, Pennisi G: L-Carnitine in the treatment of mild or moderate hepatic encephalopathy. Dig Dis. 2003;21(3):271-5. Pubmed: 14571103
  9. Oey NA, van Vlies N, Wijburg FA, Wanders RJ, Attie-Bitach T, Vaz FM: L-carnitine is synthesized in the human fetal-placental unit: potential roles in placental and fetal metabolism. Placenta. 2006 Aug;27(8):841-6. Epub 2005 Nov 18. Pubmed: 16300828
  10. Feinfeld DA, Kurian P, Cheng JT, Dilimetin G, Arriola MR, Ward L, Manis T, Carvounis CP: Effect of oral L-carnitine on serum myoglobin in hemodialysis patients. Ren Fail. 1996 Jan;18(1):91-6. Pubmed: 8820505
  11. Matalliotakis I, Koumantaki Y, Evageliou A, Matalliotakis G, Goumenou A, Koumantakis E: L-carnitine levels in the seminal plasma of fertile and infertile men: correlation with sperm quality. Int J Fertil Womens Med. 2000 May-Jun;45(3):236-40. Pubmed: 10929687
  12. Vescovo G, Ravara B, Gobbo V, Dalla Libera L: Inflammation and perturbation of the l-carnitine system in heart failure. Eur J Heart Fail. 2005 Oct;7(6):997-1002. Pubmed: 16227137
  13. Lerch R: [The effect of L-carnitine on ischemic heart disease: experimental results] Schweiz Rundsch Med Prax. 1998 Jan 21;87(4):97-100. Pubmed: 9522638
  14. Khademi A, Alleyassin A, Safdarian L, Hamed EA, Rabiee E, Haghaninezhad H: The effects of L-carnitine on sperm parameters in smoker and non-smoker patients with idiopathic sperm abnormalities. J Assist Reprod Genet. 2005 Dec;22(11-12):395-9. Pubmed: 16331536
  15. Stradomska TJ, Tylki-Szymanska A, Bentkowski Z: Very long-chain fatty acids in Rett syndrome. Eur J Pediatr. 1999 Mar;158(3):226-9. Pubmed: 10094444
  16. Hoppel CL, Genuth SM: Urinary excretion of acetylcarnitine during human diabetic and fasting ketosis. Am J Physiol. 1982 Aug;243(2):E168-72. Pubmed: 6810706
  17. Lenzi A, Sgro P, Salacone P, Paoli D, Gilio B, Lombardo F, Santulli M, Agarwal A, Gandini L: A placebo-controlled double-blind randomized trial of the use of combined l-carnitine and l-acetyl-carnitine treatment in men with asthenozoospermia. Fertil Steril. 2004 Jun;81(6):1578-84. Pubmed: 15193480
  18. Sinclair C, Gilchrist JM, Hennessey JV, Kandula M: Muscle carnitine in hypo- and hyperthyroidism. Muscle Nerve. 2005 Sep;32(3):357-9. Pubmed: 15803480
  19. Ahmad S: L-carnitine in dialysis patients. Semin Dial. 2001 May-Jun;14(3):209-17. Pubmed: 11422928
  20. Shihabi ZK, Oles KS, McCormick CP, Penry JK: Serum and tissue carnitine assay based on dialysis. Clin Chem. 1992 Aug;38(8 Pt 1):1414-7. Pubmed: 1643708
  21. Steiber A, Kerner J, Hoppel CL: Carnitine: a nutritional, biosynthetic, and functional perspective. Mol Aspects Med. 2004 Oct-Dec;25(5-6):455-73. Pubmed: 15363636
  22. Olpin SE: Fatty acid oxidation defects as a cause of neuromyopathic disease in infants and adults. Clin Lab. 2005;51(5-6):289-306. Pubmed: 15991803

Enzymes

General function:
Involved in acyltransferase activity
Specific function:
Carnitine acetylase is specific for short chain fatty acids. Carnitine acetylase seems to affect the flux through the pyruvate dehydrogenase complex. It may be involved as well in the transport of acetyl-CoA into mitochondria.
Gene Name:
CRAT
Uniprot ID:
P43155
Molecular weight:
70875.095
Reactions
Acetyl-CoA + L-Carnitine → Coenzyme A + L-Acetylcarnitinedetails
References
  1. Jogl G, Tong L: Crystal structure of carnitine acetyltransferase and implications for the catalytic mechanism and fatty acid transport. Cell. 2003 Jan 10;112(1):113-22. Pubmed: 12526798
  2. Wu D, Govindasamy L, Lian W, Gu Y, Kukar T, Agbandje-McKenna M, McKenna R: Structure of human carnitine acetyltransferase. Molecular basis for fatty acyl transfer. J Biol Chem. 2003 Apr 11;278(15):13159-65. Epub 2003 Jan 31. Pubmed: 12562770
  3. Vikramadithyan RK, Hiriyan J, Suresh J, Gershome C, Babu RK, Misra P, Rajagopalan R, Chakrabarti R: DRF 2655: a unique molecule that reduces body weight and ameliorates metabolic abnormalities. Obes Res. 2003 Feb;11(2):292-303. Pubmed: 12582227
  4. Govindasamy L, Kukar T, Lian W, Pedersen B, Gu Y, Agbandje-McKenna M, Jin S, McKenna R, Wu D: Structural and mutational characterization of L-carnitine binding to human carnitine acetyltransferase. J Struct Biol. 2004 Jun;146(3):416-24. Pubmed: 15099582
  5. Cordente AG, Lopez-Vinas E, Vazquez MI, Swiegers JH, Pretorius IS, Gomez-Puertas P, Hegardt FG, Asins G, Serra D: Redesign of carnitine acetyltransferase specificity by protein engineering. J Biol Chem. 2004 Aug 6;279(32):33899-908. Epub 2004 May 21. Pubmed: 15155769
General function:
Involved in oxidoreductase activity
Specific function:
Key enzyme in purine degradation. Catalyzes the oxidation of hypoxanthine to xanthine. Catalyzes the oxidation of xanthine to uric acid. Contributes to the generation of reactive oxygen species. Has also low oxidase activity towards aldehydes (in vitro).
Gene Name:
XDH
Uniprot ID:
P47989
Molecular weight:
146422.99
References
  1. Di Giacomo C, Latteri F, Fichera C, Sorrenti V, Campisi A, Castorina C, Russo A, Pinturo R, Vanella A: Effect of acetyl-L-carnitine on lipid peroxidation and xanthine oxidase activity in rat skeletal muscle. Neurochem Res. 1993 Nov;18(11):1157-62. Pubmed: 8255367
General function:
Involved in peroxidase activity
Specific function:
Part of the host defense system of polymorphonuclear leukocytes. It is responsible for microbicidal activity against a wide range of organisms. In the stimulated PMN, MPO catalyzes the production of hypohalous acids, primarily hypochlorous acid in physiologic situations, and other toxic intermediates that greatly enhance PMN microbicidal activity.
Gene Name:
MPO
Uniprot ID:
P05164
Molecular weight:
83867.71
References
  1. Derin N, Agac A, Bayram Z, Asar M, Izgut-Uysal VN: Effects of L-carnitine on neutrophil-mediated ischemia-reperfusion injury in rat stomach. Cell Biochem Funct. 2006 Sep-Oct;24(5):437-42. Pubmed: 16130180
General function:
Involved in acyltransferase activity
Specific function:
Beta-oxidation of fatty acids. The highest activity concerns the C6 to C10 chain length substrate. Converts the end product of pristanic acid beta oxidation, 4,8-dimethylnonanoyl-CoA, to its corresponding carnitine ester.
Gene Name:
CROT
Uniprot ID:
Q9UKG9
Molecular weight:
10213.63
Reactions
Octanoyl-CoA + L-Carnitine → Coenzyme A + L-Octanoylcarnitinedetails
References
  1. Cordente AG, Lopez-Vinas E, Vazquez MI, Swiegers JH, Pretorius IS, Gomez-Puertas P, Hegardt FG, Asins G, Serra D: Redesign of carnitine acetyltransferase specificity by protein engineering. J Biol Chem. 2004 Aug 6;279(32):33899-908. Epub 2004 May 21. Pubmed: 15155769
  2. Cordente AG, Lopez-Vinas E, Vazquez MI, Gomez-Puertas P, Asins G, Serra D, Hegardt FG: Mutagenesis of specific amino acids converts carnitine acetyltransferase into carnitine palmitoyltransferase. Biochemistry. 2006 May 16;45(19):6133-41. Pubmed: 16681386
General function:
Involved in acyltransferase activity
Specific function:
Not Available
Gene Name:
CPT1B
Uniprot ID:
Q92523
Molecular weight:
83890.705
Reactions
hexadecanoyl-CoA + L-Carnitine → Coenzyme A + L-Palmitoylcarnitinedetails
General function:
Involved in acyltransferase activity
Specific function:
Catalyzes the transfer of the acyl group of long-chain fatty acid-CoA conjugates onto carnitine, an essential step for the mitochondrial uptake of long-chain fatty acids and their subsequent beta-oxidation in the mitochondrion. Plays an important role in triglyceride metabolism.
Gene Name:
CPT1A
Uniprot ID:
P50416
Molecular weight:
86238.415
Reactions
hexadecanoyl-CoA + L-Carnitine → Coenzyme A + L-Palmitoylcarnitinedetails
References
  1. Xu ZR, Wang MQ, Mao HX, Zhan XA, Hu CH: Effects of L-carnitine on growth performance, carcass composition, and metabolism of lipids in male broilers. Poult Sci. 2003 Mar;82(3):408-13. Pubmed: 12705401
  2. Morillas M, Lopez-VVinas E, Valencia A, Serra D, Gomez-Puertas P, Hegardt FG, Asins G: Structural model of carnitine palmitoyltransferase I based on the carnitine acetyltransferase crystal. Biochem J. 2004 May 1;379(Pt 3):777-84. Pubmed: 14711372
  3. Tripodi G, Modica R, Stella A, Bigatti G, Bianchi G, Stella P: Haplotype analysis of carnitine transporters and left ventricular mass in human essential hypertension. J Ren Nutr. 2005 Jan;15(1):2-7. Pubmed: 15647998
  4. Waldner R, Laschan C, Lohninger A, Gessner M, Tuchler H, Huemer M, Spiegel W, Karlic H: Effects of doxorubicin-containing chemotherapy and a combination with L-carnitine on oxidative metabolism in patients with non-Hodgkin lymphoma. J Cancer Res Clin Oncol. 2006 Feb;132(2):121-8. Epub 2005 Nov 8. Pubmed: 16283381
  5. Shin ES, Cho SY, Lee EH, Lee SJ, Chang IS, Lee TR: Positive regulation of hepatic carnitine palmitoyl transferase 1A (CPT1A) activities by soy isoflavones and L-carnitine. Eur J Nutr. 2006 Mar;45(3):159-64. Epub 2005 Dec 20. Pubmed: 16362726
  6. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. Pubmed: 11752352
General function:
Involved in acyltransferase activity
Specific function:
Not Available
Gene Name:
CPT2
Uniprot ID:
P23786
Molecular weight:
73776.335
Reactions
hexadecanoyl-CoA + L-Carnitine → Coenzyme A + L-Palmitoylcarnitinedetails
References
  1. Barrero MJ, Camarero N, Marrero PF, Haro D: Control of human carnitine palmitoyltransferase II gene transcription by peroxisome proliferator-activated receptor through a partially conserved peroxisome proliferator-responsive element. Biochem J. 2003 Feb 1;369(Pt 3):721-9. Pubmed: 12408750
  2. Kong JY, Rabkin SW: Lovastatin does not accentuate but is rather additive to palmitate-induced apoptosis in cardiomyocytes. Prostaglandins Leukot Essent Fatty Acids. 2002 Nov;67(5):293-302. Pubmed: 12445488
  3. Rasmussen BB, Holmback UC, Volpi E, Morio-Liondore B, Paddon-Jones D, Wolfe RR: Malonyl coenzyme A and the regulation of functional carnitine palmitoyltransferase-1 activity and fat oxidation in human skeletal muscle. J Clin Invest. 2002 Dec;110(11):1687-93. Pubmed: 12464674
  4. Price NT, Jackson VN, van der Leij FR, Cameron JM, Travers MT, Bartelds B, Huijkman NC, Zammit VA: Cloning and expression of the liver and muscle isoforms of ovine carnitine palmitoyltransferase 1: residues within the N-terminus of the muscle isoform influence the kinetic properties of the enzyme. Biochem J. 2003 Jun 15;372(Pt 3):871-9. Pubmed: 12662154
  5. Lehtihet M, Welsh N, Berggren PO, Cook GA, Sjoholm A: Glibenclamide inhibits islet carnitine palmitoyltransferase 1 activity, leading to PKC-dependent insulin exocytosis. Am J Physiol Endocrinol Metab. 2003 Aug;285(2):E438-46. Epub 2003 Apr 8. Pubmed: 12684219
General function:
Involved in acyltransferase activity
Specific function:
Not Available
Gene Name:
CPT1C
Uniprot ID:
Q8TCG5
Molecular weight:
89712.575
Reactions
hexadecanoyl-CoA + L-Carnitine → Coenzyme A + L-Palmitoylcarnitinedetails
General function:
Involved in iron ion binding
Specific function:
Catalyzes the formation of L-carnitine from gamma-butyrobetaine.
Gene Name:
BBOX1
Uniprot ID:
O75936
Molecular weight:
44714.6
Reactions
4-Trimethylammoniobutanoic acid + Oxoglutaric acid + Oxygen → L-Carnitine + Succinic acid + CO(2)details
4-Trimethylammoniobutanoic acid + Oxoglutaric acid + Oxygen → L-Carnitine + Succinic acid + Carbon dioxidedetails
General function:
Lipid transport and metabolism
Specific function:
Involved in the detoxification of xenobiotics and in the activation of ester and amide prodrugs. Hydrolyzes aromatic and aliphatic esters, but has no catalytic activity toward amides or a fatty acyl-CoA ester. Hydrolyzes the methyl ester group of cocaine to form benzoylecgonine. Catalyzes the transesterification of cocaine to form cocaethylene. Displays fatty acid ethyl ester synthase activity, catalyzing the ethyl esterification of oleic acid to ethyloleate.
Gene Name:
CES1
Uniprot ID:
P23141
Molecular weight:
62520.62
References
  1. Bell FP: Carnitine ester hydrolysis in arteries from normal and cholesterol-fed rabbits and the effects of carnitine esters on arterial microsomal ACAT. Comp Biochem Physiol B. 1984;79(2):125-8. Pubmed: 6509906
General function:
Involved in transporter activity
Specific function:
Mediates the transport of acylcarnitines of different length across the mitochondrial inner membrane from the cytosol to the mitochondrial matrix for their oxidation by the mitochondrial fatty acid-oxidation pathway.
Gene Name:
SLC25A20
Uniprot ID:
O43772
Molecular weight:
32943.46
References
  1. Sekoguchi E, Sato N, Yasui A, Fukada S, Nimura Y, Aburatani H, Ikeda K, Matsuura A: A novel mitochondrial carnitine-acylcarnitine translocase induced by partial hepatectomy and fasting. J Biol Chem. 2003 Oct 3;278(40):38796-802. Epub 2003 Jul 25. Pubmed: 12882971
  2. Peluso G, Petillo O, Margarucci S, Grippo P, Melone MA, Tuccillo F, Calvani M: Differential carnitine/acylcarnitine translocase expression defines distinct metabolic signatures in skeletal muscle cells. J Cell Physiol. 2005 May;203(2):439-46. Pubmed: 15515015
  3. Tonazzi A, Giangregorio N, Indiveri C, Palmieri F: Identification by site-directed mutagenesis and chemical modification of three vicinal cysteine residues in rat mitochondrial carnitine/acylcarnitine transporter. J Biol Chem. 2005 May 20;280(20):19607-12. Epub 2005 Mar 9. Pubmed: 15757911
General function:
Involved in binding
Specific function:
Has palmitoylcarnitine transporting activity (By similarity).
Gene Name:
SLC25A29
Uniprot ID:
Q8N8R3
Molecular weight:
32061.87
References
  1. Sekoguchi E, Sato N, Yasui A, Fukada S, Nimura Y, Aburatani H, Ikeda K, Matsuura A: A novel mitochondrial carnitine-acylcarnitine translocase induced by partial hepatectomy and fasting. J Biol Chem. 2003 Oct 3;278(40):38796-802. Epub 2003 Jul 25. Pubmed: 12882971

Transporters

General function:
Involved in transporter activity
Specific function:
Mediates the Na(+)-independent transport of organic anions such as pravastatin, taurocholate, methotrexate, dehydroepiandrosterone sulfate, 17-beta-glucuronosyl estradiol, estrone sulfate, prostaglandin E2, thromboxane B2, leukotriene C3, leukotriene E4, thyroxine and triiodothyronine. May play an important role in the clearance of bile acids and organic anions from the liver
Gene Name:
SLCO1B1
Uniprot ID:
Q9Y6L6
Molecular weight:
76448.0
References
  1. Nozawa T, Tamai I, Sai Y, Nezu J, Tsuji A: Contribution of organic anion transporting polypeptide OATP-C to hepatic elimination of the opioid pentapeptide analogue [D-Ala2, D-Leu5]-enkephalin. J Pharm Pharmacol. 2003 Jul;55(7):1013-20. Pubmed: 12906759
General function:
Involved in ion transmembrane transporter activity
Specific function:
Sodium-ion dependent, high affinity carnitine transporter. Involved in the active cellular uptake of carnitine. Transports one sodium ion with one molecule of carnitine. Also transports organic cations such as tetraethylammonium (TEA) without the involvement of sodium. Also relative uptake activity ratio of carnitine to TEA is 11.3
Gene Name:
SLC22A5
Uniprot ID:
O76082
Molecular weight:
62751.1
References
  1. Lahjouji K, Elimrani I, Wu J, Mitchell GA, Qureshi IA: A heterozygote phenotype is present in the jvs +/- mutant mouse livers. Mol Genet Metab. 2002 May;76(1):76-80. Pubmed: 12175785
  2. Kristufek D, Rudorfer W, Pifl C, Huck S: Organic cation transporter mRNA and function in the rat superior cervical ganglion. J Physiol. 2002 Aug 15;543(Pt 1):117-34. Pubmed: 12181285
  3. Ohashi R, Tamai I, Inano A, Katsura M, Sai Y, Nezu J, Tsuji A: Studies on functional sites of organic cation/carnitine transporter OCTN2 (SLC22A5) using a Ser467Cys mutant protein. J Pharmacol Exp Ther. 2002 Sep;302(3):1286-94. Pubmed: 12183691
  4. Hou JW: Primary systemic carnitine deficiency presenting as recurrent Reye-like syndrome and dilated cardiomyopathy. Chang Gung Med J. 2002 Dec;25(12):832-7. Pubmed: 12635840
  5. Friedrich A, Prasad PD, Freyer D, Ganapathy V, Brust P: Molecular cloning and functional characterization of the OCTN2 transporter at the RBE4 cells, an in vitro model of the blood-brain barrier. Brain Res. 2003 Apr 4;968(1):69-79. Pubmed: 12644265
  6. Tamai I, China K, Sai Y, Kobayashi D, Nezu J, Kawahara E, Tsuji A: Na(+)-coupled transport of L-carnitine via high-affinity carnitine transporter OCTN2 and its subcellular localization in kidney. Biochim Biophys Acta. 2001 Jun 6;1512(2):273-84. Pubmed: 11406104
  7. Elimrani I, Lahjouji K, Seidman E, Roy MJ, Mitchell GA, Qureshi I: Expression and localization of organic cation/carnitine transporter OCTN2 in Caco-2 cells. Am J Physiol Gastrointest Liver Physiol. 2003 May;284(5):G863-71. Epub 2003 Jan 10. Pubmed: 12684216
  8. Ohashi R, Tamai I, Yabuuchi H, Nezu JI, Oku A, Sai Y, Shimane M, Tsuji A: Na(+)-dependent carnitine transport by organic cation transporter (OCTN2): its pharmacological and toxicological relevance. J Pharmacol Exp Ther. 1999 Nov;291(2):778-84. Pubmed: 10525100
  9. Tamai I, Ohashi R, Nezu JI, Sai Y, Kobayashi D, Oku A, Shimane M, Tsuji A: Molecular and functional characterization of organic cation/carnitine transporter family in mice. J Biol Chem. 2000 Dec 22;275(51):40064-72. Pubmed: 11010964
  10. Wu X, Huang W, Prasad PD, Seth P, Rajan DP, Leibach FH, Chen J, Conway SJ, Ganapathy V: Functional characteristics and tissue distribution pattern of organic cation transporter 2 (OCTN2), an organic cation/carnitine transporter. J Pharmacol Exp Ther. 1999 Sep;290(3):1482-92. Pubmed: 10454528
General function:
Involved in ion transmembrane transporter activity
Specific function:
Sodium-ion dependent, low affinity carnitine transporter. Probably transports one sodium ion with one molecule of carnitine. Also transports organic cations such as tetraethylammonium (TEA) without the involvement of sodium. Relative uptake activity ratio of carnitine to TEA is 1.78. A key substrate of this transporter seems to be ergothioneine (ET)
Gene Name:
SLC22A4
Uniprot ID:
Q9H015
Molecular weight:
62154.5
References
  1. Kristufek D, Rudorfer W, Pifl C, Huck S: Organic cation transporter mRNA and function in the rat superior cervical ganglion. J Physiol. 2002 Aug 15;543(Pt 1):117-34. Pubmed: 12181285
  2. Amat di San Filippo C, Wang Y, Longo N: Functional domains in the carnitine transporter OCTN2, defective in primary carnitine deficiency. J Biol Chem. 2003 Nov 28;278(48):47776-84. Epub 2003 Sep 23. Pubmed: 14506273
  3. Lamhonwah AM, Ackerley C, Onizuka R, Tilups A, Lamhonwah D, Chung C, Tao KS, Tellier R, Tein I: Epitope shared by functional variant of organic cation/carnitine transporter, OCTN1, Campylobacter jejuni and Mycobacterium paratuberculosis may underlie susceptibility to Crohn's disease at 5q31. Biochem Biophys Res Commun. 2005 Dec 2;337(4):1165-75. Epub 2005 Oct 6. Pubmed: 16246312
  4. Lash LH, Putt DA, Cai H: Membrane transport function in primary cultures of human proximal tubular cells. Toxicology. 2006 Dec 7;228(2-3):200-18. Epub 2006 Sep 1. Pubmed: 16997449
  5. Yabuuchi H, Tamai I, Nezu J, Sakamoto K, Oku A, Shimane M, Sai Y, Tsuji A: Novel membrane transporter OCTN1 mediates multispecific, bidirectional, and pH-dependent transport of organic cations. J Pharmacol Exp Ther. 1999 May;289(2):768-73. Pubmed: 10215651
  6. Tamai I, Ohashi R, Nezu JI, Sai Y, Kobayashi D, Oku A, Shimane M, Tsuji A: Molecular and functional characterization of organic cation/carnitine transporter family in mice. J Biol Chem. 2000 Dec 22;275(51):40064-72. Pubmed: 11010964
General function:
Involved in transporter activity
Specific function:
High affinity carnitine transporter; the uptake is partially sodium-ion dependent. Thought to mediate the L-carnitine secretion mechanism from testis epididymal epithelium into the lumen which is involved in the maturation of spermatozoa. Also transports organic cations such as tetraethylammonium (TEA) and doxorubicin. The uptake of TEA is inhibited by various organic cations. The uptake of doxorubicin is sodium-independent
Gene Name:
SLC22A16
Uniprot ID:
Q86VW1
Molecular weight:
64613.6
References
  1. Enomoto A, Wempe MF, Tsuchida H, Shin HJ, Cha SH, Anzai N, Goto A, Sakamoto A, Niwa T, Kanai Y, Anders MW, Endou H: Molecular identification of a novel carnitine transporter specific to human testis. Insights into the mechanism of carnitine recognition. J Biol Chem. 2002 Sep 27;277(39):36262-71. Epub 2002 Jun 27. Pubmed: 12089149