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Record Information
Version3.6
Creation Date2005-11-16 15:48:42 UTC
Update Date2013-05-13 23:03:59 UTC
HMDB IDHMDB00574
Secondary Accession NumbersNone
Metabolite Identification
Common NameL-Cysteine
DescriptionCysteine is a naturally occurring, sulfur-containing amino acid that is found in most proteins, although only in small quantities. Cysteine is unique amongst the twenty natural amino acids as it contains a thiol group. Thiol groups can undergo oxidation/reduction (redox) reactions; when cysteine is oxidized it can form cystine, which is two cysteine residues joined by a disulfide bond. This reaction is reversible: as reduction of this disulphide bond regenerates two cysteine molecules. The disulphide bonds of cystine are crucial to defining the structures of many proteins. Cysteine is often involved in electron-transfer reactions, and help the enzyme catalyze its reaction. Cysteine is also part of the antioxidant glutathione. N-acetyl-L-cysteine (NAC) is a form of cysteine where an acetyl group is attached to cysteine's nitrogen atom and is sold as a dietary supplement. Cysteine is named after cystine, which comes from the Greek word kustis meaning bladder - cystine was first isolated from kidney stones. As cysteine contains a sulphydryl group, it can undergo redox reactions. Oxidation of cysteine can produce a disulfide bond with another thiol, or further oxidation can produce sulphfinic or sulfonic acids. The cysteine thiol group is also a nucleophile and can undergo addition and substitution reactions. Thiol groups become much more reactive when they are ionized, and cysteine residues in proteins have pKa values close to neutrality, so are often in their reactive thiolate form in the cell. The thiol group also has a high affinity for heavy metals and proteins containing cysteine will bind metals such as mercury, lead and cadmium tightly. Due to this ability to undergo redox reactions, cysteine has antioxidant properties. Cysteine is an important source of sulfur in human metabolism, and although it is classified as a non-essential amino acid, cysteine may be essential for infants, the elderly, and individuals with certain metabolic disease or who suffer from malabsorption syndromes. Cysteine may at some point be recognized as an essential or conditionally essential amino acid. (http://en.wikipedia.org/wiki/Cysteine). Cysteine is important in energy metabolism. As cystine, it is a structural component of many tissues and hormones. Cysteine has clinical uses ranging from baldness to psoriasis to preventing smoker's hack. In some cases, oral cysteine therapy has proved excellent for treatment of asthmatics, enabling them to stop theophylline and other medications. Cysteine also enhances the effect of topically applied silver, tin and zinc salts in preventing dental cavities. In the future, cysteine may play a role in the treatment of cobalt toxicity, diabetes, psychosis, cancer and seizures. (http://www.dcnutrition.com/AminoAcids/).
Structure
Thumb
Synonyms
  1. (+)-2-Amino-3-mercaptopropionic acid
  2. (2R)-2-amino-3-mercaptopropanoate
  3. (2R)-2-amino-3-mercaptopropanoic acid
  4. (2R)-2-amino-3-sulfanylpropanoate
  5. (2R)-2-amino-3-sulfanylpropanoic acid
  6. (R)-(+)-cysteine
  7. (R)-2-amino-3-mercapto-Propanoate
  8. (R)-2-amino-3-mercapto-Propanoic acid
  9. (R)-2-Amino-3-mercaptopropanoate
  10. (R)-2-Amino-3-mercaptopropanoic acid
  11. (R)-cysteine
  12. 2-Amino-3-mercaptopropanoate
  13. 2-Amino-3-mercaptopropanoic acid
  14. 2-Amino-3-mercaptopropionate
  15. 2-Amino-3-mercaptopropionic acid
  16. 3-Mercapto-L-Alanine
  17. Acetylcysteine
  18. alpha-Amino-beta-thiolpropionic acid
  19. B-Mercaptoalanine
  20. beta-Mercaptoalanine
  21. Carbocysteine
  22. Cisteina
  23. Cisteinum
  24. Cystein
  25. Cysteine
  26. Cysteinum
  27. Free cysteine
  28. Half-cystine
  29. L Cysteine
  30. L-(+)-Cysteine
  31. L-2-Amino-3-mercaptopropanoate
  32. L-2-Amino-3-mercaptopropanoic acid
  33. L-2-Amino-3-mercaptopropionic acid
  34. L-Cystein
  35. L-Cysteine
  36. Polycysteine
  37. Thioserine
Chemical FormulaC3H7NO2S
Average Molecular Weight121.158
Monoisotopic Molecular Weight121.019749163
IUPAC Name(2R)-2-amino-3-sulfanylpropanoic acid
Traditional IUPAC NameL-cysteine
CAS Registry Number52-90-4
SMILES
N[C@@H](CS)C(O)=O
InChI Identifier
InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m0/s1
InChI KeyXUJNEKJLAYXESH-REOHCLBHSA-N
Chemical Taxonomy
KingdomOrganic Compounds
Super ClassAmino Acids, Peptides, and Analogues
ClassAmino Acids and Derivatives
Sub ClassAlpha Amino Acids and Derivatives
Other Descriptors
  • Aliphatic Acyclic Compounds
  • Common amino acids(KEGG)
  • cysteine zwitterion(ChEBI)
Substituents
  • Alkylthiol
  • Carboxylic Acid
  • Primary Aliphatic Amine (Alkylamine)
  • Thiol (Sulfanyl Compound)
Direct ParentAlpha Amino Acids and Derivatives
Ontology
StatusDetected and Quantified
Origin
  • Drug metabolite
  • Endogenous
Biofunction
  • Component of Cysteine metabolism
  • Component of Glycine, serine and threonine metabolism
  • Component of Methionine metabolism
  • Component of Nitrogen metabolism
  • Component of Selenoamino acid metabolism
  • Component of Taurine and hypotaurine metabolism
  • Waste products
ApplicationNot Available
Cellular locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point220 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility277 mg/mL at 25 °CBEILSTEIN
LogP-2.49HANSCH,C ET AL. (1995)
Predicted Properties
PropertyValueSource
water solubility23.1 g/LALOGPS
logP-2.6ALOGPS
logP-2.8ChemAxon
logS-0.72ALOGPS
pKa (strongest acidic)2.35ChemAxon
pKa (strongest basic)9.05ChemAxon
physiological charge0ChemAxon
hydrogen acceptor count3ChemAxon
hydrogen donor count3ChemAxon
polar surface area63.32ChemAxon
rotatable bond count2ChemAxon
refractivity28.22ChemAxon
polarizability11.46ChemAxon
Spectra
SpectraGC-MSMS/MSLC-MS1D NMR2D NMR
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
Biofluid Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Urine
Tissue Location
  • Adrenal Cortex
  • Epidermis
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Muscle
  • Myelin
  • Neuron
  • Placenta
  • Platelet
  • Prostate
  • Skeletal Muscle
  • Spleen
  • Testes
  • Thyroid Gland
Pathways
NameSMPDB LinkKEGG Link
Cysteine MetabolismSMP00013map00270
Glutathione MetabolismSMP00015map00480
Glycine and Serine MetabolismSMP00004map00260
Methionine MetabolismSMP00033map00270
Pantothenate and CoA BiosynthesisSMP00027map00770
Taurine and Hypotaurine MetabolismSMP00021map00430
Transcription/TranslationSMP00019Not Available
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified197.00 +/- 56.00 uMAdolescent (13-18 years old)BothNormal details
BloodDetected and Quantified131.00 +/- 40.00 uMInfant (0-1 year old)BothNormal details
BloodDetected and Quantified210.00 +/- 40.00 uMChildren (1-13 years old)BothNormal details
BloodDetected and Quantified212.00 +/- 23.00 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified52.0 (41.0-63.0) uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified33.5 +/- 10.3 uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.054 (0.017-0.108) uMAdult (>18 years old)Not SpecifiedNormal details
UrineDetected and Quantified3.322 (1.447-5.197) umol/mmol creatinineAdult (>18 years old)BothNormal
    details
    UrineDetected and Quantified30.32 +/- 24.58 umol/mmol creatinineInfant (0-1 year old)BothNormal details
    UrineDetected and Quantified81.0 (36.7-147.6) umol/mmol creatinineAdult (>18 years old)Both
    Normal
    details
    UrineDetected and Quantified32.00 +/- 10.00 umol/mmol creatinineInfant (0-1 year old)BothNormal details
    UrineDetected and Quantified28.00 +/- 9.00 umol/mmol creatinineChildren (1-13 years old)BothNormal details
    UrineDetected and Quantified34.4 +/- 11.00 umol/mmol creatinineAdolescent (13-18 years old)BothNormal details
    UrineDetected and Quantified33.4 +/- 15.5 umol/mmol creatinineAdult (>18 years old)BothNormal details
    UrineDetected and Quantified65.8 (23.1-134.5) umol/mmol creatinineAdult (>18 years old)Both
    Normal
    details
    UrineDetected and Quantified14.9 umol/mmol creatinineAdult (>18 years old)BothNormal details
    Abnormal Concentrations
    BiofluidStatusValueAgeSexConditionReferenceDetails
    BloodDetected and Quantified0.355 (0.157-1.146) uMAdult (>18 years old)Not SpecifiedMultiple sclerosis details
    BloodDetected and Quantified0.420 (0.154-0.874) uMAdult (>18 years old)Not SpecifiedStroke details
    BloodDetected and Quantified0.415 (0.199-1.038) uMAdult (>18 years old)Not SpecifiedPeripheral neuropathy details
    BloodDetected and Quantified0.491 (0.247-1.764) uMAdult (>18 years old)Not SpecifiedDementia (Alzheimer's and non-Alzheimer's) details
    BloodDetected and Quantified13.0 (10.0-16.0) uMAdult (>18 years old)BothAIDS details
    BloodDetected and Quantified12.81 +/- 2.17 uMElderly (>65 years old)BothAlzheimer's Disease details
    Cerebrospinal Fluid (CSF)Detected and Quantified0.042 (0.022-0.10) uMAdult (>18 years old)Not SpecifiedMultiple sclerosis details
    Cerebrospinal Fluid (CSF)Detected and Quantified0.048 (0.018-0.10) uMAdult (>18 years old)Not SpecifiedStroke details
    Cerebrospinal Fluid (CSF)Detected and Quantified0.034 (0.018-0.075) uMAdult (>18 years old)Not SpecifiedPeripheral neuropathy details
    Cerebrospinal Fluid (CSF)Detected and Quantified0.047 (0.025-0.125) uMAdult (>18 years old)Not SpecifiedDementia (Alzheimer's and non-Alzheimer's) details
    Associated Disorders and Diseases
    Disease References
    AIDS
    1. Naisbitt DJ, Vilar FJ, Stalford AC, Wilkins EG, Pirmohamed M, Park BK: Plasma cysteine deficiency and decreased reduction of nitrososulfamethoxazole with HIV infection. AIDS Res Hum Retroviruses. 2000 Dec 10;16(18):1929-38. Pubmed: 11153075
    Dementia
    1. Obeid R, Kasoha M, Knapp JP, Kostopoulos P, Becker G, Fassbender K, Herrmann W: Folate and methylation status in relation to phosphorylated tau protein(181P) and beta-amyloid(1-42) in cerebrospinal fluid. Clin Chem. 2007 Jun;53(6):1129-36. Epub 2007 Mar 23. Pubmed: 17384003
    Multiple sclerosis
    1. Obeid R, Kasoha M, Knapp JP, Kostopoulos P, Becker G, Fassbender K, Herrmann W: Folate and methylation status in relation to phosphorylated tau protein(181P) and beta-amyloid(1-42) in cerebrospinal fluid. Clin Chem. 2007 Jun;53(6):1129-36. Epub 2007 Mar 23. Pubmed: 17384003
    Peripheral neuropathy
    1. Obeid R, Kasoha M, Knapp JP, Kostopoulos P, Becker G, Fassbender K, Herrmann W: Folate and methylation status in relation to phosphorylated tau protein(181P) and beta-amyloid(1-42) in cerebrospinal fluid. Clin Chem. 2007 Jun;53(6):1129-36. Epub 2007 Mar 23. Pubmed: 17384003
    Stroke
    1. Obeid R, Kasoha M, Knapp JP, Kostopoulos P, Becker G, Fassbender K, Herrmann W: Folate and methylation status in relation to phosphorylated tau protein(181P) and beta-amyloid(1-42) in cerebrospinal fluid. Clin Chem. 2007 Jun;53(6):1129-36. Epub 2007 Mar 23. Pubmed: 17384003
    Associated OMIM IDs
    DrugBank IDDB00151
    DrugBank Metabolite IDDBMET00503
    Phenol Explorer Compound IDNot Available
    Phenol Explorer Metabolite IDNot Available
    FoodDB IDFDB012678
    KNApSAcK IDC00001351
    Chemspider ID5653
    KEGG Compound IDNot Available
    BioCyc IDCYS
    BiGG ID33843
    Wikipedia LinkL-Cysteine
    NuGOwiki LinkHMDB00574
    Metagene LinkHMDB00574
    METLIN ID5556
    PubChem Compound5862
    PDB IDCYS
    ChEBI ID17561
    References
    Synthesis ReferenceKumagai, Hidehiko; Tanaka, Hideyuki; Sejima, Shunsuke; Yamada, Hideaki. Elimination and replacement reactions of b-chloro-L-alanine by cysteine desulfhydrase from Aerobacter aerogenes. Agricultural and Biological Chemistry (1977), 41(10), 2071-5.
    Material Safety Data Sheet (MSDS)Download (PDF)
    General References
    1. Yu FH, Westenbroek RE, Silos-Santiago I, McCormick KA, Lawson D, Ge P, Ferriera H, Lilly J, DiStefano PS, Catterall WA, Scheuer T, Curtis R: Sodium channel beta4, a new disulfide-linked auxiliary subunit with similarity to beta2. J Neurosci. 2003 Aug 20;23(20):7577-85. Pubmed: 12930796
    2. 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
    3. Nicholson JK, O'Flynn MP, Sadler PJ, Macleod AF, Juul SM, Sonksen PH: Proton-nuclear-magnetic-resonance studies of serum, plasma and urine from fasting normal and diabetic subjects. Biochem J. 1984 Jan 15;217(2):365-75. Pubmed: 6696735
    4. Cynober LA: Plasma amino acid levels with a note on membrane transport: characteristics, regulation, and metabolic significance. Nutrition. 2002 Sep;18(9):761-6. Pubmed: 12297216
    5. Kersemans V, Cornelissen B, Kersemans K, Bauwens M, Achten E, Dierckx RA, Mertens J, Slegers G: In vivo characterization of 123/125I-2-iodo-L-phenylalanine in an R1M rhabdomyosarcoma athymic mouse model as a potential tumor tracer for SPECT. J Nucl Med. 2005 Mar;46(3):532-9. Pubmed: 15750170
    6. Sandmann J, Schwedhelm KS, Tsikas D: Specific transport of S-nitrosocysteine in human red blood cells: Implications for formation of S-nitrosothiols and transport of NO bioactivity within the vasculature. FEBS Lett. 2005 Aug 1;579(19):4119-24. Pubmed: 16023102
    7. Paivalainen S, Suokas M, Lahti O, Heape AM: Degraded myelin-associated glycoprotein (dMAG) formation from pure human brain myelin-associated glycoprotein (MAG) is not mediated by calpain or cathepsin L-like activities. J Neurochem. 2003 Feb;84(3):533-45. Pubmed: 12558973
    8. Iyer S, Leonidas DD, Swaminathan GJ, Maglione D, Battisti M, Tucci M, Persico MG, Acharya KR: The crystal structure of human placenta growth factor-1 (PlGF-1), an angiogenic protein, at 2.0 A resolution. J Biol Chem. 2001 Apr 13;276(15):12153-61. Epub 2000 Nov 7. Pubmed: 11069911
    9. Nishiya Y, Yoshida Y, Yoshimura M, Fukamachi H, Nakano Y: Homogeneous enzymatic assay for L-cysteine with betaC-S lyase. Biosci Biotechnol Biochem. 2005 Nov;69(11):2244-6. Pubmed: 16306712
    10. Santamaria I, Velasco G, Cazorla M, Fueyo A, Campo E, Lopez-Otin C: Cathepsin L2, a novel human cysteine proteinase produced by breast and colorectal carcinomas. Cancer Res. 1998 Apr 15;58(8):1624-30. Pubmed: 9563472
    11. Eriksson A, Tohonen V, Wedell A, Nordqvist K: Isolation of the human testatin gene and analysis in patients with abnormal gonadal development. Mol Hum Reprod. 2002 Jan;8(1):8-15. Pubmed: 11756564
    12. Kaminska J, Wisniewska A, Koscielak J: Chemical modifications of alpha1,6-fucosyltransferase define amino acid residues of catalytic importance. Biochimie. 2003 Mar-Apr;85(3-4):303-10. Pubmed: 12770769
    13. Li Y, Gamper N, Shapiro MS: Single-channel analysis of KCNQ K+ channels reveals the mechanism of augmentation by a cysteine-modifying reagent. J Neurosci. 2004 Jun 2;24(22):5079-90. Pubmed: 15175377
    14. Lindzen M, Gottschalk KE, Fuzesi M, Garty H, Karlish SJ: Structural interactions between FXYD proteins and Na+,K+-ATPase: alpha/beta/FXYD subunit stoichiometry and cross-linking. J Biol Chem. 2006 Mar 3;281(9):5947-55. Epub 2005 Dec 21. Pubmed: 16373350
    15. Norris FA, Wilson MP, Wallis TS, Galyov EE, Majerus PW: SopB, a protein required for virulence of Salmonella dublin, is an inositol phosphate phosphatase. Proc Natl Acad Sci U S A. 1998 Nov 24;95(24):14057-9. Pubmed: 9826652
    16. Foss CA, Mease RC, Fan H, Wang Y, Ravert HT, Dannals RF, Olszewski RT, Heston WD, Kozikowski AP, Pomper MG: Radiolabeled small-molecule ligands for prostate-specific membrane antigen: in vivo imaging in experimental models of prostate cancer. Clin Cancer Res. 2005 Jun 1;11(11):4022-8. Pubmed: 15930336
    17. Kozaki K, Miyaishi O, Asai N, Iida K, Sakata K, Hayashi M, Nishida T, Matsuyama M, Shimizu S, Kaneda T, et al.: Tissue distribution of ERp61 and association of its increased expression with IgG production in hybridoma cells. Exp Cell Res. 1994 Aug;213(2):348-58. Pubmed: 8050492
    18. Amberger VR, Hensel T, Ogata N, Schwab ME: Spreading and migration of human glioma and rat C6 cells on central nervous system myelin in vitro is correlated with tumor malignancy and involves a metalloproteolytic activity. Cancer Res. 1998 Jan 1;58(1):149-58. Pubmed: 9426071
    19. Zhang JT, Li QX, Wang D, Zhu ZL, Yang YH, Cui DS, Wang MW, Sun XF: Up-regulation of PINCH in the stroma of oral squamous cell carcinoma predicts nodal metastasis. Oncol Rep. 2005 Dec;14(6):1519-22. Pubmed: 16273248
    20. Taveau M, Bourg N, Sillon G, Roudaut C, Bartoli M, Richard I: Calpain 3 is activated through autolysis within the active site and lyses sarcomeric and sarcolemmal components. Mol Cell Biol. 2003 Dec;23(24):9127-35. Pubmed: 14645524
    21. Naisbitt DJ, Vilar FJ, Stalford AC, Wilkins EG, Pirmohamed M, Park BK: Plasma cysteine deficiency and decreased reduction of nitrososulfamethoxazole with HIV infection. AIDS Res Hum Retroviruses. 2000 Dec 10;16(18):1929-38. Pubmed: 11153075
    22. Baker DH, Czarnecki-Maulden GL: Pharmacologic role of cysteine in ameliorating or exacerbating mineral toxicities. J Nutr. 1987 Jun;117(6):1003-10. Pubmed: 3298579
    23. Bulaj G, Kortemme T, Goldenberg DP: Ionization-reactivity relationships for cysteine thiols in polypeptides. Biochemistry. 1998 Jun 23;37(25):8965-72. Pubmed: 9636038

    Enzymes

    General function:
    Involved in transferase activity, transferring nitrogenous groups
    Specific function:
    Plays a key role in amino acid metabolism (By similarity).
    Gene Name:
    GOT1
    Uniprot ID:
    P17174
    Molecular weight:
    46247.14
    Reactions
    L-Cysteine + Oxoglutaric acid → 3-Mercaptopyruvic acid + DL-Glutamatedetails
    References
    1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
    2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
    General function:
    Involved in transferase activity, transferring nitrogenous groups
    Specific function:
    Catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA). Plays a key role in amino acid metabolism. Important for metabolite exchange between mitochondria and cytosol. Facilitates cellular uptake of long-chain free fatty acids.
    Gene Name:
    GOT2
    Uniprot ID:
    P00505
    Molecular weight:
    47517.285
    Reactions
    L-Cysteine + Oxoglutaric acid → 3-Mercaptopyruvic acid + DL-Glutamatedetails
    General function:
    Involved in proteolysis
    Specific function:
    Broad specificity aminopeptidase. Plays a role in the final digestion of peptides generated from hydrolysis of proteins by gastric and pancreatic proteases. May play a critical role in the pathogenesis of cholesterol gallstone disease. May be involved in the metabolism of regulatory peptides of diverse cell types, responsible for the processing of peptide hormones, such as angiotensin III and IV, neuropeptides, and chemokines. Found to cleave antigen peptides bound to major histocompatibility complex class II molecules of presenting cells and to degrade neurotransmitters at synaptic junctions. Is also implicated as a regulator of IL-8 bioavailability in the endometrium, and therefore may contribute to the regulation of angiogenesis. Is used as a marker for acute myeloid leukemia and plays a role in tumor invasion. In case of human coronavirus 229E (HCoV-229E) infection, serves as receptor for HCoV-229E spike glycoprotein. Mediates as well human cytomegalovirus (HCMV) infection.
    Gene Name:
    ANPEP
    Uniprot ID:
    P15144
    Molecular weight:
    Not Available
    Reactions
    Cysteinylglycine + Water → L-Cysteine + Glycinedetails
    General function:
    Involved in glutamate-cysteine ligase activity
    Specific function:
    Not Available
    Gene Name:
    GCLC
    Uniprot ID:
    P48506
    Molecular weight:
    68629.42
    Reactions
    Adenosine triphosphate + L-Glutamic acid + L-Cysteine → ADP + Phosphoric acid + Gamma-Glutamylcysteinedetails
    References
    1. Ashida H, Sawa Y, Shibata H: Cloning, biochemical and phylogenetic characterizations of gamma-glutamylcysteine synthetase from Anabaena sp. PCC 7120. Plant Cell Physiol. 2005 Apr;46(4):557-62. Epub 2005 Feb 2. Pubmed: 15695431
    2. Srivastava S, Chan C: Application of metabolic flux analysis to identify the mechanisms of free fatty acid toxicity to human hepatoma cell line. Biotechnol Bioeng. 2008 Feb 1;99(2):399-410. Pubmed: 17615559
    General function:
    Involved in oxidoreductase activity
    Specific function:
    Not Available
    Gene Name:
    GCLM
    Uniprot ID:
    P48507
    Molecular weight:
    30726.7
    References
    1. Ashida H, Sawa Y, Shibata H: Cloning, biochemical and phylogenetic characterizations of gamma-glutamylcysteine synthetase from Anabaena sp. PCC 7120. Plant Cell Physiol. 2005 Apr;46(4):557-62. Epub 2005 Feb 2. Pubmed: 15695431
    General function:
    Involved in pyridoxal phosphate binding
    Specific function:
    Catalyzes the last step in the trans-sulfuration pathway from methionine to cysteine. Has broad substrate specificity. Converts cystathionine to cysteine, ammonia and 2-oxobutanoate. Converts two cysteine molecules to lanthionine and hydrogen sulfide. Can also accept homocysteine as substrate. Specificity depends on the levels of the endogenous substrates. Generates the endogenous signaling molecule hydrogen sulfide (H2S), and so contributes to the regulation of blood pressure. Acts as a cysteine-protein sulfhydrase by mediating sulfhydration of target proteins: sulfhydration consists of converting -SH groups into -SSH on specific cysteine residues of target proteins such as GAPDH, PTPN1 and NF-kappa-B subunit RELA, thereby regulating their function.
    Gene Name:
    CTH
    Uniprot ID:
    P32929
    Molecular weight:
    41259.91
    Reactions
    L-Cystathionine + Water → L-Cysteine + Ammonia + 2-Ketobutyric aciddetails
    L-Cysteine + Water → Hydrogen sulfide + Pyruvic acid + Ammoniadetails
    References
    1. Fiorucci S, Antonelli E, Mencarelli A, Orlandi S, Renga B, Rizzo G, Distrutti E, Shah V, Morelli A: The third gas: H2S regulates perfusion pressure in both the isolated and perfused normal rat liver and in cirrhosis. Hepatology. 2005 Sep;42(3):539-48. Pubmed: 16108046
    2. Zhang H, Zhi L, Moore PK, Bhatia M: Role of hydrogen sulfide in cecal ligation and puncture-induced sepsis in the mouse. Am J Physiol Lung Cell Mol Physiol. 2006 Jun;290(6):L1193-201. Epub 2006 Jan 20. Pubmed: 16428267
    3. Wallace JL, Dicay M, McKnight W, Martin GR: Hydrogen sulfide enhances ulcer healing in rats. FASEB J. 2007 Dec;21(14):4070-6. Epub 2007 Jul 18. Pubmed: 17634391
    General function:
    Involved in peptidase activity
    Specific function:
    Responsible for the biosynthesis of pyroglutamyl peptides. Has a bias against acidic and tryptophan residues adjacent to the N-terminal glutaminyl residue and a lack of importance of chain length after the second residue. Also catalyzes N-terminal pyroglutamate formation. In vitro, catalyzes pyroglutamate formation of N-terminally truncated form of APP amyloid-beta peptides [Glu-3]-beta-amyloid. May be involved in the N-terminal pyroglutamate formation of several amyloid-related plaque-forming peptides.
    Gene Name:
    QPCT
    Uniprot ID:
    Q16769
    Molecular weight:
    40876.14
    General function:
    Involved in cysteine biosynthetic process from serine
    Specific function:
    Only known pyridoxal phosphate-dependent enzyme that contains heme. Important regulator of hydrogen sulfide, especially in the brain, utilizing cysteine instead of serine to catalyze the formation of hydrogen sulfide. Hydrogen sulfide is a gastratransmitter with signaling and cytoprotective effects such as acting as a neuromodulator in the brain to protect neurons against hypoxic injury (By similarity).
    Gene Name:
    CBS
    Uniprot ID:
    P35520
    Molecular weight:
    60586.05
    Reactions
    L-Serine + Hydrogen sulfide → L-Cysteine + Waterdetails
    References
    1. Zhang H, Zhi L, Moore PK, Bhatia M: Role of hydrogen sulfide in cecal ligation and puncture-induced sepsis in the mouse. Am J Physiol Lung Cell Mol Physiol. 2006 Jun;290(6):L1193-201. Epub 2006 Jan 20. Pubmed: 16428267
    2. Lowicka E, Beltowski J: Hydrogen sulfide (H2S) - the third gas of interest for pharmacologists. Pharmacol Rep. 2007 Jan-Feb;59(1):4-24. Pubmed: 17377202
    3. Tamizhselvi R, Moore PK, Bhatia M: Hydrogen sulfide acts as a mediator of inflammation in acute pancreatitis: in vitro studies using isolated mouse pancreatic acinar cells. J Cell Mol Med. 2007 Mar-Apr;11(2):315-26. Pubmed: 17488480
    4. Oh GS, Pae HO, Lee BS, Kim BN, Kim JM, Kim HR, Jeon SB, Jeon WK, Chae HJ, Chung HT: Hydrogen sulfide inhibits nitric oxide production and nuclear factor-kappaB via heme oxygenase-1 expression in RAW264.7 macrophages stimulated with lipopolysaccharide. Free Radic Biol Med. 2006 Jul 1;41(1):106-19. Epub 2006 Apr 25. Pubmed: 16781459
    5. Bhatia M, Wong FL, Fu D, Lau HY, Moochhala SM, Moore PK: Role of hydrogen sulfide in acute pancreatitis and associated lung injury. FASEB J. 2005 Apr;19(6):623-5. Epub 2005 Jan 25. Pubmed: 15671155
    General function:
    Involved in catalytic activity
    Specific function:
    Not Available
    Gene Name:
    GSS
    Uniprot ID:
    P48637
    Molecular weight:
    52384.325
    References
    1. Tanaka T, Halicka HD, Huang X, Traganos F, Darzynkiewicz Z: Constitutive histone H2AX phosphorylation and ATM activation, the reporters of DNA damage by endogenous oxidants. Cell Cycle. 2006 Sep;5(17):1940-5. Epub 2006 Sep 1. Pubmed: 16940754
    General function:
    Involved in aminopeptidase activity
    Specific function:
    Presumably involved in the processing and regular turnover of intracellular proteins. Catalyzes the removal of unsubstituted N-terminal amino acids from various peptides.
    Gene Name:
    LAP3
    Uniprot ID:
    P28838
    Molecular weight:
    Not Available
    Reactions
    Cysteinylglycine + Water → L-Cysteine + Glycinedetails
    General function:
    Involved in carboxy-lyase activity
    Specific function:
    Not Available
    Gene Name:
    CSAD
    Uniprot ID:
    Q9Y600
    Molecular weight:
    55022.79
    References
    1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
    2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
    3. Chan-Palay V, Lin CT, Palay S, Yamamoto M, Wu JY: Taurine in the mammalian cerebellum: demonstration by autoradiography with [3H]taurine and immunocytochemistry with antibodies against the taurine-synthesizing enzyme, cysteine-sulfinic acid decarboxylase. Proc Natl Acad Sci U S A. 1982 Apr;79(8):2695-9. Pubmed: 6953423
    4. Guion-Rain M-C, Portemer C, Chatagner F: Rat liver cysteine sulfinate decarboxylase: purification, new appraisal of the molecular weight and determination of catalytic properties. Biochim Biophys Acta. 1975 Mar 28;384(1):265-76. Pubmed: 236774
    5. Daniels KM, Stipanuk MH: The effect of dietary cysteine level on cysteine metabolism in rats. J Nutr. 1982 Nov;112(11):2130-41. Pubmed: 7131091
    General function:
    Involved in iron ion binding
    Specific function:
    Initiates several important metabolic pathways related to pyruvate and several sulfurate compounds including sulfate, hypotaurine and taurine. Critical regulator of cellular cysteine concentrations. Has an important role in maintaining the hepatic concentation of intracellular free cysteine within a proper narrow range.
    Gene Name:
    CDO1
    Uniprot ID:
    Q16878
    Molecular weight:
    22971.745
    Reactions
    L-Cysteine + Oxygen → 3-Sulfinoalaninedetails
    References
    1. Roopnarinesingh ES, Steventon GB, Harris RM, Waring RH, Mitchell SC: Induction of cysteine dioxygenase activity by oral administration of cysteine analogues to the rat: implications for drug efficacy and safety. Drug Metabol Drug Interact. 2005;21(2):75-86. Pubmed: 16355974
    2. McCoy JG, Bailey LJ, Bitto E, Bingman CA, Aceti DJ, Fox BG, Phillips GN Jr: Structure and mechanism of mouse cysteine dioxygenase. Proc Natl Acad Sci U S A. 2006 Feb 28;103(9):3084-9. Epub 2006 Feb 21. Pubmed: 16492780
    3. Ye S, Wu X, Wei L, Tang D, Sun P, Bartlam M, Rao Z: An insight into the mechanism of human cysteine dioxygenase: Key roles of the thioether-bonded tyrosine-cysteine cofactor. J Biol Chem. 2006 Nov 29;. Pubmed: 17135237
    4. Jin HF, DU SX, Zhao X, Zhang SQ, Tian Y, Bu DF, Tang CS, DU JB: [Significance of endogenous sulfur dioxide in the regulation of cardiovascular system]. Beijing Da Xue Xue Bao. 2007 Aug 18;39(4):423-5. Pubmed: 17657274
    General function:
    Involved in methylated-DNA-[protein]-cysteine S-methyltransferase activity
    Specific function:
    Involved in the cellular defense against the biological effects of O6-methylguanine (O6-MeG) in DNA. Repairs alkylated guanine in DNA by stoichiometrically transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. This is a suicide reaction:the enzyme is irreversibly inactivated
    Gene Name:
    MGMT
    Uniprot ID:
    P16455
    Molecular weight:
    21645.8
    References
    1. Niture SK, Velu CS, Smith QR, Bhat GJ, Srivenugopal KS: Increased expression of the MGMT repair protein mediated by cysteine prodrugs and chemopreventative natural products in human lymphocytes and tumor cell lines. Carcinogenesis. 2007 Feb;28(2):378-89. Epub 2006 Aug 31. Pubmed: 16950796
    General function:
    Involved in metabolic process
    Specific function:
    Catalyzes the removal of elemental sulfur from cysteine to produce alanine. It supplies the inorganic sulfur for iron-sulfur (Fe-S) clusters. May be involved in the biosynthesis of molybdenum cofactor.
    Gene Name:
    NFS1
    Uniprot ID:
    Q9Y697
    Molecular weight:
    44361.485
    Reactions
    L-Cysteine + acceptor → L-Alanine + S-sulfanyl-acceptordetails
    [Enzyme]-cysteine + L-Cysteine → [Enzyme]-S-sulfanylcysteine + L-Alaninedetails
    References
    1. You D, Wang L, Yao F, Zhou X, Deng Z: A novel DNA modification by sulfur: DndA is a NifS-like cysteine desulfurase capable of assembling DndC as an iron-sulfur cluster protein in Streptomyces lividans. Biochemistry. 2007 May 22;46(20):6126-33. Epub 2007 May 1. Pubmed: 17469805
    2. Ding H, Harrison K, Lu J: Thioredoxin reductase system mediates iron binding in IscA and iron delivery for the iron-sulfur cluster assembly in IscU. J Biol Chem. 2005 Aug 26;280(34):30432-7. Epub 2005 Jun 28. Pubmed: 15985427
    3. Ding B, Smith ES, Ding H: Mobilization of the iron centre in IscA for the iron-sulphur cluster assembly in IscU. Biochem J. 2005 Aug 1;389(Pt 3):797-802. Pubmed: 15828873
    4. Yang J, Bitoun JP, Ding H: Interplay of IscA and IscU in biogenesis of iron-sulfur clusters. J Biol Chem. 2006 Sep 22;281(38):27956-63. Epub 2006 Jul 27. Pubmed: 16877383
    5. Layer G, Ollagnier-de Choudens S, Sanakis Y, Fontecave M: Iron-sulfur cluster biosynthesis: characterization of Escherichia coli CYaY as an iron donor for the assembly of [2Fe-2S] clusters in the scaffold IscU. J Biol Chem. 2006 Jun 16;281(24):16256-63. Epub 2006 Apr 9. Pubmed: 16603772
    General function:
    Coenzyme transport and metabolism
    Specific function:
    Catalyzes the first step in the biosynthesis of coenzyme A from vitamin B5, where cysteine is conjugated to 4'-phosphopantothenate to form 4-phosphopantothenoylcysteine.
    Gene Name:
    PPCS
    Uniprot ID:
    Q9HAB8
    Molecular weight:
    15645.035
    Reactions
    Cytidine triphosphate + D-4'-Phosphopantothenate + L-Cysteine → Cytidine monophosphate + Pyrophosphate + N-((R)-4'-phosphopantothenoyl)-L-cysteinedetails
    Adenosine triphosphate + D-4'-Phosphopantothenate + L-Cysteine → Adenosine monophosphate + Pyrophosphate + 4-Phosphopantothenoylcysteinedetails
    Cytidine triphosphate + D-4'-Phosphopantothenate + L-Cysteine → Cytidine monophosphate + Pyrophosphate + 4-Phosphopantothenoylcysteinedetails
    General function:
    Involved in catalytic activity
    Specific function:
    Required for the function of light chain amino-acid transporters. Involved in sodium-independent, high-affinity transport of large neutral amino acids such as phenylalanine, tyrosine, leucine, arginine and tryptophan. Involved in guiding and targeting of LAT1 and LAT2 to the plasma membrane. When associated with SLC7A6 or SLC7A7 acts as an arginine/glutamine exchanger, following an antiport mechanism for amino acid transport, influencing arginine release in exchange for extracellular amino acids. Plays a role in nitric oxide synthesis in human umbilical vein endothelial cells (HUVECs) via transport of L-arginine. Required for normal and neoplastic cell growth. When associated with SLC7A5/LAT1, is also involved in the transport of L-DOPA across the blood-brain barrier, and that of thyroid hormones triiodothyronine (T3) and thyroxine (T4) across the cell membrane in tissues such as placenta. Involved in the uptake of methylmercury (MeHg) when administered as the L-cysteine or D,L-homocysteine complexes, and hence plays a role in metal ion homeostasis and toxicity. When associated with SLC7A5 or SLC7A8, involved in the cellular activity of small molecular weight nitrosothiols, via the stereoselective transport of L- nitrosocysteine (L-CNSO) across the transmembrane. Together with ICAM1, regulates the transport activity LAT2 in polarized intestinal cells, by generating and delivering intracellular signals. When associated with SLC7A5, plays an important role in transporting L-leucine from the circulating blood to the retina across the inner blood-retinal barrier
    Gene Name:
    SLC3A2
    Uniprot ID:
    P08195
    Molecular weight:
    67993.3
    General function:
    Involved in folic acid binding
    Specific function:
    Mediates high affinity thiamine uptake, propably via a proton anti-port mechanism. Has no folate transport activity.
    Gene Name:
    SLC19A3
    Uniprot ID:
    Q9BZV2
    Molecular weight:
    55664.265
    References
    1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
    2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
    General function:
    Involved in nucleotide binding
    Specific function:
    Not Available
    Gene Name:
    CARS2
    Uniprot ID:
    Q9HA77
    Molecular weight:
    62223.345
    Reactions
    Adenosine triphosphate + L-Cysteine + tRNA(Cys) → Adenosine monophosphate + Pyrophosphate + L-cysteinyl-tRNA(Cys)details
    Adenosine triphosphate + L-Cysteine + tRNA(Cys) → Adenosine monophosphate + Pyrophosphate + L-Cysteinyl-tRNA(Cys)details
    References
    1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
    2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
    General function:
    Involved in oxidoreductase activity
    Specific function:
    Involved in the degradation of prenylated proteins. Cleaves the thioether bond of prenyl-L-cysteines, such as farnesylcysteine and geranylgeranylcysteine.
    Gene Name:
    PCYOX1
    Uniprot ID:
    Q9UHG3
    Molecular weight:
    56639.66
    Reactions
    An S-prenyl-L-cysteine + Oxygen + Water → a prenal + L-Cysteine + Hydrogen peroxidedetails
    Farnesylcysteine + Oxygen + Water → 2-trans,6-trans-Farnesal + L-Cysteine + Hydrogen peroxidedetails
    General function:
    Involved in metabolic process
    Specific function:
    Sulfurates the molybdenum cofactor. Sulfation of molybdenum is essential for xanthine dehydrogenase (XDH) and aldehyde oxidase (ADO) enzymes in which molybdenum cofactor is liganded by 1 oxygen and 1 sulfur atom in active form. In vitro, the C-terminal domain is able to reduce N-hydroxylated prodrugs, such as benzamidoxime.
    Gene Name:
    MOCOS
    Uniprot ID:
    Q96EN8
    Molecular weight:
    98118.965
    Reactions
    Molybdopterin + L-Cysteine + Hydrogen Ion → thio-molybdenum cofactor + L-Alanine + Waterdetails
    General function:
    Involved in nucleotide binding
    Specific function:
    Not Available
    Gene Name:
    CARS
    Uniprot ID:
    P49589
    Molecular weight:
    94636.8
    Reactions
    Adenosine triphosphate + L-Cysteine + tRNA(Cys) → Adenosine monophosphate + Pyrophosphate + L-cysteinyl-tRNA(Cys)details
    Adenosine triphosphate + L-Cysteine + tRNA(Cys) → Adenosine monophosphate + Pyrophosphate + L-Cysteinyl-tRNA(Cys)details
    References
    1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
    2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
    General function:
    Involved in acyltransferase activity
    Specific function:
    Catalyzes the formation of 5-oxoproline from gamma-glutamyl dipeptides and may play a significant role in glutathione homeostasis. Induces release of cytochrome c from mitochondria with resultant induction of apoptosis.
    Gene Name:
    GGCT
    Uniprot ID:
    O75223
    Molecular weight:
    19091.635
    Reactions
    Gamma-Glutamylcysteine → Pyroglutamic acid + L-Cysteinedetails
    General function:
    Involved in iron ion binding
    Specific function:
    L-CYSTEINE + O(2) = 3-SULFINOALANINE
    Gene Name:
    CDO-1
    Uniprot ID:
    Q16857
    Molecular weight:
    6589.4
    References
    1. Jin HF, DU SX, Zhao X, Zhang SQ, Tian Y, Bu DF, Tang CS, DU JB: [Significance of endogenous sulfur dioxide in the regulation of cardiovascular system]. Beijing Da Xue Xue Bao. 2007 Aug 18;39(4):423-5. Pubmed: 17657274
    2. Roopnarinesingh ES, Steventon GB, Harris RM, Waring RH, Mitchell SC: Induction of cysteine dioxygenase activity by oral administration of cysteine analogues to the rat: implications for drug efficacy and safety. Drug Metabol Drug Interact. 2005;21(2):75-86. Pubmed: 16355974
    3. Ye S, Wu X, Wei L, Tang D, Sun P, Bartlam M, Rao Z: An insight into the mechanism of human cysteine dioxygenase: Key roles of the thioether-bonded tyrosine-cysteine cofactor. J Biol Chem. 2006 Nov 29;. Pubmed: 17135237
    4. McCoy JG, Bailey LJ, Bitto E, Bingman CA, Aceti DJ, Fox BG, Phillips GN Jr: Structure and mechanism of mouse cysteine dioxygenase. Proc Natl Acad Sci U S A. 2006 Feb 28;103(9):3084-9. Epub 2006 Feb 21. Pubmed: 16492780
    5. Pierce BS, Gardner JD, Bailey LJ, Brunold TC, Fox BG: Characterization of the nitrosyl adduct of substrate-bound mouse cysteine dioxygenase by electron paramagnetic resonance: electronic structure of the active site and mechanistic implications. Biochemistry. 2007 Jul 24;46(29):8569-78. Epub 2007 Jun 28. Pubmed: 17602574

    Transporters

    General function:
    Involved in transport
    Specific function:
    Sodium-independent, high-affinity transport of small and large neutral amino acids such as alanine, serine, threonine, cysteine, phenylalanine, tyrosine, leucine, arginine and tryptophan, when associated with SLC3A2/4F2hc. Acts as an amino acid exchanger. Has higher affinity for L-phenylalanine than LAT1 but lower affinity for glutamine and serine. L-alanine is transported at physiological concentrations. Plays a role in basolateral (re)absorption of neutral amino acids. Involved in the uptake of methylmercury (MeHg) when administered as the L-cysteine or D,L-homocysteine complexes, and hence plays a role in metal ion homeostasis and toxicity. Involved in the cellular activity of small molecular weight nitrosothiols, via the stereoselective transport of L-nitrosocysteine (L-CNSO) across the transmembrane. Plays an essential role in the reabsorption of neutral amino acids from the epithelial cells to the bloodstream in the kidney
    Gene Name:
    SLC7A8
    Uniprot ID:
    Q9UHI5
    Molecular weight:
    58381.1
    General function:
    Involved in transmembrane transport
    Specific function:
    Sodium-independent transporter that mediates the update of aromatic acid. Can function as a net efflux pathway for aromatic amino acids in the basosolateral epithelial cells
    Gene Name:
    SLC16A10
    Uniprot ID:
    Q8TF71
    Molecular weight:
    55492.1
    References
    1. Kim DK, Kanai Y, Chairoungdua A, Matsuo H, Cha SH, Endou H: Expression cloning of a Na+-independent aromatic amino acid transporter with structural similarity to H+/monocarboxylate transporters. J Biol Chem. 2001 May 18;276(20):17221-8. Epub 2001 Feb 20. Pubmed: 11278508