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Record Information
Version3.6
Creation Date2005-11-16 15:48:42 UTC
Update Date2016-09-22 21:06:07 UTC
HMDB IDHMDB00192
Secondary Accession NumbersNone
Metabolite Identification
Common NameL-Cystine
DescriptionCystine is an oxidized dimeric form of cysteine. It is formed by linking two cysteine residues via a disulfide bond (cys-S-S-cys) between the -SH groups. Cystine is found in high concentrations in the cells of the immune system, skeletal and connective tissues, skin, digestive enzymes, and in hair. Hair and skin are 10-14% cystine. Cystine is the preferred form of cysteine for the synthesis of glutathione in cells involved in the immune function including macrophages and astrocytes. Lymphocytes and neurons prefer cysteine for glutathione production. Optimizing glutathione levels in macrophages and astrocytes with cystine allows these cells to provide cysteine to lymphocytes and neurons directly upon demand. (http://en.wikipedia.org/wiki/Cystine).
Structure
Thumb
Synonyms
ValueSource
(R,R)-3,3'-Dithiobis(2-aminopropanoic acid)ChEBI
(R-(R*,r*))-3,3'-dithiobis(2-aminopropanoic acid)ChEBI
3,3'-Dithiobis-L-alanineChEBI
beta,Beta'-diamino-beta,beta'-dicarboxydiethyl disulfideChEBI
beta,Beta'-dithiodialanineChEBI
Bis(beta-amino-beta-carboxyethyl) disulfideChEBI
e921ChEBI
L-alpha-diamino-beta-Dithiolactic acidChEBI
L-DicysteineChEBI
Oxidized L-cysteineChEBI
(R,R)-3,3'-Dithiobis(2-aminopropanoate)Generator
(R-(R*,r*))-3,3'-dithiobis(2-aminopropanoate)Generator
b,Beta'-diamino-b,beta'-dicarboxydiethyl disulfideGenerator
b,Beta'-diamino-b,beta'-dicarboxydiethyl disulphideGenerator
beta,Beta'-diamino-beta,beta'-dicarboxydiethyl disulphideGenerator
β,beta'-diamino-β,beta'-dicarboxydiethyl disulfideGenerator
β,beta'-diamino-β,beta'-dicarboxydiethyl disulphideGenerator
b,Beta'-dithiodialanineGenerator
β,beta'-dithiodialanineGenerator
Bis(b-amino-b-carboxyethyl) disulfideGenerator
Bis(b-amino-b-carboxyethyl) disulphideGenerator
Bis(beta-amino-beta-carboxyethyl) disulphideGenerator
Bis(β-amino-β-carboxyethyl) disulfideGenerator
Bis(β-amino-β-carboxyethyl) disulphideGenerator
L-a-diamino-b-DithiolactateGenerator
L-a-diamino-b-Dithiolactic acidGenerator
L-alpha-diamino-beta-DithiolactateGenerator
L-α-diamino-β-dithiolactateGenerator
L-α-diamino-β-dithiolactic acidGenerator
(-)-CystineHMDB
(R-(R*,r*))-3,3'-dithiobisHMDB
2-amino-3-(2-amino-2-Carboxy-ethyl)disulfanyl-propanoateHMDB
2-amino-3-(2-amino-2-Carboxy-ethyl)disulfanyl-propanoic acidHMDB
2-amino-3-[(2-amino-2-Carboxyethyl)dithio]propanoateHMDB
2-amino-3-[(2-amino-2-Carboxyethyl)dithio]propanoic acidHMDB
3,3'-DithiobisHMDB
3,3'-Dithiobis[2-amino-[R-(r*,r*)]-propanoateHMDB
3,3'-Dithiobis[2-amino-[R-(r*,r*)]-propanoic acidHMDB
3,3'-DithiodialanineHMDB
b,B'-diamino-b,b'-dicarboxydiethyl disulfideHMDB
b,B'-dithiodialanineHMDB
beta,Beta'-dithiobisalanineHMDB
Bis(b-amino-beta-carboxyethyl) disulfideHMDB
Cysteine disulfideHMDB
CystinHMDB
CystineHMDB
Cystine acidHMDB
D(+)-3,3'-Dithiobis(2-aminopropanoateHMDB
D(+)-3,3'-Dithiobis(2-aminopropanoic acidHMDB
DicysteineHMDB
GelucystineHMDB
L-(-)-CystineHMDB
L-Cysteine disulfideHMDB
L-CystinHMDB
[R-(R*,r*)]-3,3'-dithiobisHMDB
Chemical FormulaC6H12N2O4S2
Average Molecular Weight240.3
Monoisotopic Molecular Weight240.023848262
IUPAC Name(2R)-2-amino-3-{[(2R)-2-amino-2-carboxyethyl]disulfanyl}propanoic acid
Traditional NameL-cystine
CAS Registry Number56-89-3
SMILES
N[C@@H](CSSC[C@H](N)C(O)=O)C(O)=O
InChI Identifier
InChI=1S/C6H12N2O4S2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)/t3-,4-/m0/s1
InChI KeyInChIKey=LEVWYRKDKASIDU-IMJSIDKUSA-N
Chemical Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentL-alpha-amino acids
Alternative Parents
Substituents
  • L-alpha-amino acid
  • D-alpha-amino acid
  • Dicarboxylic acid or derivatives
  • Dialkyldisulfide
  • Organic disulfide
  • Sulfenyl compound
  • Carboxylic acid
  • Hydrocarbon derivative
  • Primary amine
  • Organosulfur compound
  • Organooxygen compound
  • Organonitrogen compound
  • Primary aliphatic amine
  • Carbonyl group
  • Amine
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Ontology
StatusDetected and Quantified
Origin
  • Endogenous
Biofunction
  • Essential amino acid
ApplicationNot Available
Cellular locations
  • Cytoplasm
  • Extracellular
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point260.5 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility0.19 mg/mLNot Available
LogP-5.08CHMELIK,J ET AL. (1991)
Predicted Properties
PropertyValueSource
Water Solubility16.8 mg/mLALOGPS
logP-3.2ALOGPS
logP-5.9ChemAxon
logS-1.2ALOGPS
pKa (Strongest Acidic)1.56ChemAxon
pKa (Strongest Basic)9.34ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count6ChemAxon
Hydrogen Donor Count4ChemAxon
Polar Surface Area126.64 Å2ChemAxon
Rotatable Bond Count7ChemAxon
Refractivity54.87 m3·mol-1ChemAxon
Polarizability22.77 Å3ChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (4 TMS)splash10-00kb-0950000000-a803bc05843192dd737dView in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies)splash10-00kb-0940000000-f82b905ef9e7c9e47552View in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (4 TMS)splash10-00di-9850000000-49b9a52a8387d6d6f272View in MoNA
GC-MSGC-MS Spectrum - GC-MS (4 TMS)splash10-014j-1970000000-9576699202733d4fd7edView in MoNA
GC-MSGC-MS Spectrum - GC-MSNot Available
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-0006-0890000000-51a32ee40240e45646bcView in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-00di-9700000000-4054924ddfb90f120e67View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-00di-9100000000-085d45702e61de0f8e4dView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, NegativeNot Available
MSMass Spectrum (Electron Ionization)splash10-000x-9000000000-ae0f516d71e6a49fe52fView in MoNA
1D NMR1H NMR SpectrumNot Available
1D NMR13C NMR SpectrumNot Available
2D NMR[1H,1H] 2D NMR SpectrumNot Available
2D NMR[1H,13C] 2D NMR SpectrumNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Feces
  • Urine
Tissue Location
  • All Tissues
PathwaysNot Available
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified26-77 uMNewborn (0-30 days old)Both
Normal
    • BC Children's Hos...
details
BloodDetected and Quantified130.0 +/- 20.0 uMNewborn (0-30 days old)Not SpecifiedNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified26-61 uMInfant (1 - 3 months old)Both
Normal
    • BC Children's Hos...
details
BloodDetected and Quantified91.0 +/- 20.0 uMChildren (1-13 years old)MaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified8-68 uMChildren (3 months - 6 years old)Both
Normal
    • BC Children's Hos...
details
BloodDetected and Quantified96.0 +/- 19.0 uMChildren (1-13 years old)BothNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified15-65 uMChildren (6 - 18 years old)Both
Normal
    • BC Children's Hos...
details
BloodDetected and Quantified118.0 +/- 17.0 uMAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified109.0 +/- 24.0 uMAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified87.0 +/- 13.0 uMChildren (1-13 years old)Not SpecifiedNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified62.9 +/- 27.8 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified109.0 +/- 18.0 uMAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified107.0 +/- 23.0 uMAdult (>18 years old)Not SpecifiedNormal
    • Geigy Scientific ...
details
Cerebrospinal Fluid (CSF)Detected and Quantified0.1 +/- 0.1 uMAdult (>18 years old)BothNormal
    • Geigy Scientific ...
details
Cerebrospinal Fluid (CSF)Detected and Quantified0.29 +/- 0.27 uMAdult (>18 years old)BothNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0-1.5 uMChildren (0 - 10 years old)Both
Normal
    • BC Children's Hos...
details
Cerebrospinal Fluid (CSF)Detected and Quantified0-1.5 uMAdolescent (>11 years old)Both
Normal
    • BC Children's Hos...
details
FecesDetected but not QuantifiedNot ApplicableNot SpecifiedBoth
Normal
details
UrineDetected and Quantified3.618 (1.316-5.921) umol/mmol creatinineAdult (>18 years old)BothNormal
    details
    UrineDetected and Quantified10.5 umol/mmol creatinineAdult (>18 years old)BothNormal details
    UrineDetected and Quantified2.92-54.16 umol/mmol creatinineAdult (>18 years old)BothNormal
      • David F. Putnam C...
    details
    UrineDetected and Quantified12.10 - 43.64 umol/mmol creatinineNewborn (0-30 days old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified6.22 - 26.12 umol/mmol creatinineInfant (1 - 6 months old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified5.09 - 15.60 umol/mmol creatinineInfant (6 months - <1 year old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified3.84 - 13.23 umol/mmol creatinineChildren (1 - 2 years old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified2.71 - 15.60 umol/mmol creatinineChildren (2 - 4 years old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified2.71 - 12.10 umol/mmol creatinineChildren (4 - 13 years old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified1.70 - 20.92 umol/mmol creatinineAdolescent (13 - 21 years old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified1.70 - 17.86 umol/mmol creatinineAdult (>21 years old)Both
    Normal
      • BC Children's Hos...
    details
    UrineDetected and Quantified10.05 +/- 28.34 umol/mmol creatinineInfant (0-1 year old)BothNormal details
    UrineDetected and Quantified12.5 (5.0-24.6) umol/mmol creatinineAdult (>18 years old)Both
    Normal
    details
    UrineDetected and Quantified0.15 (0.1-0.2) umol/mmol creatinineNewborn (0-30 days old)BothNormal
      • Geigy Scientific ...
      • West Cadwell, N.J...
      • Basel, Switzerlan...
    details
    UrineDetected and Quantified3.6 +/- 2.0 umol/mmol creatinineChildren (1-13 years old)MaleNormal
      • Geigy Scientific ...
      • West Cadwell, N.J...
      • Basel, Switzerlan...
    details
    UrineDetected and Quantified9.0 +/- 3.0 umol/mmol creatinineAdult (>18 years old)MaleNormal
      • Geigy Scientific ...
      • West Cadwell, N.J...
      • Basel, Switzerlan...
    details
    UrineDetected and Quantified7.0 +/- 3.0 umol/mmol creatinineAdult (>18 years old)FemaleNormal
      • Geigy Scientific ...
      • West Cadwell, N.J...
      • Basel, Switzerlan...
    details
    UrineDetected but not QuantifiedNot ApplicableAdult (>18 years old)BothNormal details
    UrineDetected and Quantified2.61 +/- 1.42 umol/mmol creatinineAdult (>18 years old)BothNormal details
    UrineDetected and Quantified27.821 +/- 17.962 umol/mmol creatinineChildren (1 - 13 years old)Not Specified
    Normal
      • Mordechai, Hien, ...
    details
    Abnormal Concentrations
    BiofluidStatusValueAgeSexConditionReferenceDetails
    BloodDetected but not QuantifiedNot ApplicableAdult (>18 years old)BothColorectal cancer details
    BloodDetected and Quantified28.6 (24.2-33.0) uMChildren (1-13 years old)BothJuvenile myoclonic epilepsy (JME) details
    BloodDetected and Quantified30.1 (24.5-35.7) uMAdult (>18 years old)BothAcute seizures details
    BloodDetected and Quantified37.2 (34.6-39.8) uMAdult (>18 years old)BothRefractory localization-related epilepsy (RLE) details
    BloodDetected and Quantified209.0 +/- 46.0 uMElderly (>65 years old)BothAlzheimer's Disease details
    Cerebrospinal Fluid (CSF)Detected and Quantified0.31 +/- 0.06 uMAdult (>18 years old)BothParkinson's Disease details
    Cerebrospinal Fluid (CSF)Detected and Quantified7.8 +/- 2.5 umol/mmol creatinineAdult (>18 years old)BothAlzheimer's disease details
    UrineDetected and Quantified65.0 (30.0-100.0) umol/mmol creatinineAdult (>18 years old)BothCystinuria details
    UrineDetected and Quantified575.0 (150.0 -1000.0) umol/mmol creatinineChildren (1-13 years old)BothCystinuria details
    UrineDetected and Quantified> 117 umol/mmol creatinineAdult (>18 years old)BothCystinuria details
    UrineDetected and Quantified17.486 +/- 14.104 umol/mmol creatinineChildren (1 - 13 years old)Not Specified
    Eosinophilic esophagitis
      • Mordechai, Hien, ...
    details
    UrineDetected and Quantified72.03 +/- 12.0 umol/mmol creatinineAdult (>18 years old)BothAlzheimer's disease details
    Associated Disorders and Diseases
    Disease References
    Acute seizures
    1. Rainesalo S, Keranen T, Palmio J, Peltola J, Oja SS, Saransaari P: Plasma and cerebrospinal fluid amino acids in epileptic patients. Neurochem Res. 2004 Jan;29(1):319-24. [14992292 ]
    Alzheimer's disease
    1. Fonteh AN, Harrington RJ, Tsai A, Liao P, Harrington MG: Free amino acid and dipeptide changes in the body fluids from Alzheimer's disease subjects. Amino Acids. 2007 Feb;32(2):213-24. Epub 2006 Oct 10. [17031479 ]
    Cystinuria
    1. Sakhaee K: Pathogenesis and medical management of cystinuria. Semin Nephrol. 1996 Sep;16(5):435-47. [8890399 ]
    2. MetaGene [Link]
    Juvenile myoclonic epilepsy
    1. Rainesalo S, Keranen T, Palmio J, Peltola J, Oja SS, Saransaari P: Plasma and cerebrospinal fluid amino acids in epileptic patients. Neurochem Res. 2004 Jan;29(1):319-24. [14992292 ]
    Parkinson's disease
    1. Engelborghs S, Marescau B, De Deyn PP: Amino acids and biogenic amines in cerebrospinal fluid of patients with Parkinson's disease. Neurochem Res. 2003 Aug;28(8):1145-50. [12834252 ]
    Refractory localization-related epilepsy
    1. Rainesalo S, Keranen T, Palmio J, Peltola J, Oja SS, Saransaari P: Plasma and cerebrospinal fluid amino acids in epileptic patients. Neurochem Res. 2004 Jan;29(1):319-24. [14992292 ]
    Associated OMIM IDs
    DrugBank IDDB00138
    DrugBank Metabolite IDNot Available
    Phenol Explorer Compound IDNot Available
    Phenol Explorer Metabolite IDNot Available
    FoodDB IDFDB012563
    KNApSAcK IDNot Available
    Chemspider ID60997
    KEGG Compound IDC00491
    BioCyc IDCYSTINE
    BiGG ID35134
    Wikipedia LinkCystine
    NuGOwiki LinkHMDB00192
    Metagene LinkHMDB00192
    METLIN ID5207
    PubChem Compound67678
    PDB IDNot Available
    ChEBI ID16283
    References
    Synthesis ReferenceGrossi, Loris; Montevecchi, Pier Carlo. S-Nitrosocysteine and Cystine from Reaction of Cysteine with Nitrous Acid. A Kinetic Investigation. Journal of Organic Chemistry (2002), 67(24), 8625-8630.
    Material Safety Data Sheet (MSDS)Download (PDF)
    General References
    1. Shoemaker JD, Elliott WH: Automated screening of urine samples for carbohydrates, organic and amino acids after treatment with urease. J Chromatogr. 1991 Jan 2;562(1-2):125-38. [2026685 ]
    2. Engelborghs S, Marescau B, De Deyn PP: Amino acids and biogenic amines in cerebrospinal fluid of patients with Parkinson's disease. Neurochem Res. 2003 Aug;28(8):1145-50. [12834252 ]
    3. Rainesalo S, Keranen T, Palmio J, Peltola J, Oja SS, Saransaari P: Plasma and cerebrospinal fluid amino acids in epileptic patients. Neurochem Res. 2004 Jan;29(1):319-24. [14992292 ]
    4. Rumpold H, Mascher K, Untergasser G, Plas E, Hermann M, Berger P: Trans-differentiation of prostatic stromal cells leads to decreased glycoprotein hormone alpha production. J Clin Endocrinol Metab. 2002 Nov;87(11):5297-303. [12414905 ]
    5. Alexander S, Ison C: Evaluation of commercial kits for the identification of Neisseria gonorrhoeae. J Med Microbiol. 2005 Sep;54(Pt 9):827-31. [16091433 ]
    6. Terada T, Maeda H, Okamoto K, Nishinaka T, Mizoguchi T, Nishihara T: Modulation of glutathione S-transferase activity by a thiol/disulfide exchange reaction and involvement of thioltransferase. Arch Biochem Biophys. 1993 Jan;300(1):495-500. [8424686 ]
    7. Sonies BC, Almajid P, Kleta R, Bernardini I, Gahl WA: Swallowing dysfunction in 101 patients with nephropathic cystinosis: benefit of long-term cysteamine therapy. Medicine (Baltimore). 2005 May;84(3):137-46. [15879904 ]
    8. Mogil'naia GM, Shubich MG: [Comparison of the histochemical bases of epidermis differentiation in vertebrates] Arkh Anat Gistol Embriol. 1976 Mar;70(3):46-52. [1275714 ]
    9. Peters T, Thaete C, Wolf S, Popp A, Sedlmeier R, Grosse J, Nehls MC, Russ A, Schlueter V: A mouse model for cystinuria type I. Hum Mol Genet. 2003 Sep 1;12(17):2109-20. [12923163 ]
    10. Park M, Helip-Wooley A, Thoene J: Lysosomal cystine storage augments apoptosis in cultured human fibroblasts and renal tubular epithelial cells. J Am Soc Nephrol. 2002 Dec;13(12):2878-87. [12444206 ]
    11. Rossi S, Herrine SK, Navarro VJ: Cystinosis as a cause of noncirrhotic portal hypertension. Dig Dis Sci. 2005 Jul;50(7):1372-5. [16047489 ]
    12. Sakhaee K: Pathogenesis and medical management of cystinuria. Semin Nephrol. 1996 Sep;16(5):435-47. [8890399 ]
    13. Orakzai N, Hanbury DC, Farrington K: Screening for biochemical abnormalities in urolithiasis patients. J Ayub Med Coll Abbottabad. 2004 Apr-Jun;16(2):60-3. [15455621 ]
    14. Mitchell BF, Chibbar R: Synthesis and metabolism of oxytocin in late gestation in human decidua. Adv Exp Med Biol. 1995;395:365-80. [8713992 ]
    15. Behr T, Becker W, Hannappel E, Goldenberg DM, Wolf F: Targeting of liver metastases of colorectal cancer with IgG, F(ab')2, and Fab' anti-carcinoembryonic antigen antibodies labeled with 99mTc: the role of metabolism and kinetics. Cancer Res. 1995 Dec 1;55(23 Suppl):5777s-5785s. [7493346 ]
    16. Coe FL, Evan A, Worcester E: Kidney stone disease. J Clin Invest. 2005 Oct;115(10):2598-608. [16200192 ]
    17. Kubilus J, MacDonald MJ, Baden HP: Epidermal proteins of cultured human and bovine keratinocytes. Biochim Biophys Acta. 1979 Jun 19;578(2):484-92. [486533 ]
    18. Tezuka T, Takahashi M: The cystine-rich envelope protein from human epidermal stratum corneum cells. J Invest Dermatol. 1987 Jan;88(1):47-51. [3794387 ]
    19. Worcester EM, Coe FL, Evan AP, Parks JH: Reduced renal function and benefits of treatment in cystinuria vs other forms of nephrolithiasis. BJU Int. 2006 Jun;97(6):1285-90. [16686727 ]
    20. Allen JW, Shanker G, Tan KH, Aschner M: The consequences of methylmercury exposure on interactive functions between astrocytes and neurons. Neurotoxicology. 2002 Dec;23(6):755-9. [12520765 ]

    Enzymes

    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-Cystine + Water → Pyruvic acid + Ammonia + Thiocysteinedetails
    General function:
    Involved in catalytic activity
    Specific function:
    Involved in the high-affinity, sodium-independent transport of cystine and neutral and dibasic amino acids (system B(0,+)-like activity). May function as an activator of SLC7A9 and be involved in the high-affinity reabsorption of cystine in the kidney tubule
    Gene Name:
    SLC3A1
    Uniprot ID:
    Q07837
    Molecular weight:
    78851.4
    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. [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. [17016423 ]
    General function:
    Involved in transport
    Specific function:
    Involved in the high-affinity, sodium-independent transport of cystine and neutral and dibasic amino acids (system b(0,+)-like activity). Thought to be responsible for the high- affinity reabsorption of cystine in the kidney tubule
    Gene Name:
    SLC7A9
    Uniprot ID:
    P82251
    Molecular weight:
    53480.8
    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. [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. [17016423 ]
    General function:
    Involved in transport
    Specific function:
    Sodium-independent, high-affinity exchange of anionic amino acids with high specificity for anionic form of cystine and glutamate.
    Gene Name:
    SLC7A11
    Uniprot ID:
    Q9UPY5
    Molecular weight:
    55422.44
    References
    1. Tomi M, Hosoya K, Takanaga H, Ohtsuki S, Terasaki T: Induction of xCT gene expression and L-cystine transport activity by diethyl maleate at the inner blood-retinal barrier. Invest Ophthalmol Vis Sci. 2002 Mar;43(3):774-9. [11867597 ]
    2. Hosoya K, Tomi M, Ohtsuki S, Takanaga H, Saeki S, Kanai Y, Endou H, Naito M, Tsuruo T, Terasaki T: Enhancement of L-cystine transport activity and its relation to xCT gene induction at the blood-brain barrier by diethyl maleate treatment. J Pharmacol Exp Ther. 2002 Jul;302(1):225-31. [12065721 ]
    3. Ruiz E, Siow RC, Bartlett SR, Jenner AM, Sato H, Bannai S, Mann GE: Vitamin C inhibits diethylmaleate-induced L-cystine transport in human vascular smooth muscle cells. Free Radic Biol Med. 2003 Jan 1;34(1):103-10. [12498985 ]
    4. Bridges CC, Zalups RK: Cystine and glutamate transport in renal epithelial cells transfected with human system x(-) (c). Kidney Int. 2005 Aug;68(2):653-64. [16014042 ]
    5. Tomi M, Funaki T, Abukawa H, Katayama K, Kondo T, Ohtsuki S, Ueda M, Obinata M, Terasaki T, Hosoya K: Expression and regulation of L-cystine transporter, system xc-, in the newly developed rat retinal Muller cell line (TR-MUL). Glia. 2003 Sep;43(3):208-17. [12898700 ]
    General function:
    Involved in sodium:dicarboxylate symporter activity
    Specific function:
    Transporter for alanine, serine, cysteine, and threonine. Exhibits sodium dependence
    Gene Name:
    SLC1A4
    Uniprot ID:
    P43007
    Molecular weight:
    55722.5
    General function:
    Involved in L-cystine transmembrane transporter activity
    Specific function:
    Thought to transport cystine out of lysosomes
    Gene Name:
    CTNS
    Uniprot ID:
    O60931
    Molecular weight:
    41737.6
    References
    1. Kalatzis V, Cherqui S, Antignac C, Gasnier B: Cystinosin, the protein defective in cystinosis, is a H(+)-driven lysosomal cystine transporter. EMBO J. 2001 Nov 1;20(21):5940-9. [11689434 ]

    Transporters

    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. [11278508 ]