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Record Information
Version4.0
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2019-03-14 17:59:21 UTC
HMDB IDHMDB0000099
Secondary Accession Numbers
  • HMDB0003614
  • HMDB00099
  • HMDB03614
Metabolite Identification
Common NameL-Cystathionine
DescriptionCystathionine is a dipeptide formed by serine and homocysteine. Cystathioninuria is a prominent manifestation of vitamin-B6 deficiency. The transsulfuration of methionine yields homocysteine, which combines with serine to form cystathionine, the proximate precursor of cysteine through the enzymatic activity of cystathionase. In conditions in which cystathionine gamma-synthase or cystathionase is deficient, for example, there is cystathioninuria. Although cystathionine has not been detected in normal human serum or plasma by most conventional methods, gas chromatographic/mass spectrometric methodology detected a mean concentration of cystathionine in normal human serum of 140 nM, with a range of 65 to 301 nM. Cystathionine concentrations in CSF have been 10, 1, and 0.5 uM, and "not detected". Only traces (i.e., <1 uM) of cystathionine are present in normal CSF.587. Gamma-cystathionase deficiency (also known as Cystathioninuria), which is an autosomal recessive disorder (NIH: 2428), provided the first instance in which, in a human, the major biochemical abnormality due to a defined enzyme defect was clearly shown to be alleviated by administration of large doses of pyridoxine. The response in gamma-cystathionase-deficient patients is not attributable to correction of a preexisting deficiency of this vitamin (OMMBID, Chap. 88).
Structure
Data?1547234043
Synonyms
ValueSource
(R)-S-(2-Amino-2-carboxyethyl)-L-homocysteineChEBI
L-(+)-CystathionineChEBI
S-(beta-Amino-beta-carboxyethyl)homocysteineChEBI
S-(b-Amino-b-carboxyethyl)homocysteineGenerator
S-(Β-amino-β-carboxyethyl)homocysteineGenerator
CystathionineHMDB
S-[(2R)-2-Amino-2-carboxyethyl]-L-homocysteineHMDB
[R-(R*,s*)]-2-amino-4-[(2-amino-2-carboxyethyl)thio]-butanoateHMDB
[R-(R*,s*)]-2-amino-4-[(2-amino-2-carboxyethyl)thio]-butanoic acidHMDB
Chemical FormulaC7H14N2O4S
Average Molecular Weight222.262
Monoisotopic Molecular Weight222.067427636
IUPAC Name(2S)-2-amino-4-{[(2R)-2-amino-2-carboxyethyl]sulfanyl}butanoic acid
Traditional NameL-cystathionine
CAS Registry Number56-88-2
SMILES
N[C@@H](CCSC[C@H](N)C(O)=O)C(O)=O
InChI Identifier
InChI=1S/C7H14N2O4S/c8-4(6(10)11)1-2-14-3-5(9)7(12)13/h4-5H,1-3,8-9H2,(H,10,11)(H,12,13)/t4-,5-/m0/s1
InChI KeyILRYLPWNYFXEMH-WHFBIAKZSA-N
Chemical Taxonomy
Description belongs to the class of organic compounds known as l-cysteine-s-conjugates. L-cysteine-S-conjugates are compounds containing L-cysteine where the thio-group is conjugated.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentL-cysteine-S-conjugates
Alternative Parents
Substituents
  • L-cysteine-s-conjugate
  • Alpha-amino acid
  • L-alpha-amino acid
  • Thia fatty acid
  • Dicarboxylic acid or derivatives
  • Fatty acyl
  • Fatty acid
  • Amino acid
  • Carboxylic acid
  • Thioether
  • Dialkylthioether
  • Sulfenyl compound
  • Organic nitrogen compound
  • Hydrocarbon derivative
  • Organic oxide
  • Primary amine
  • Organosulfur compound
  • Organooxygen compound
  • Organonitrogen compound
  • Primary aliphatic amine
  • Organopnictogen compound
  • Organic oxygen compound
  • Carbonyl group
  • Amine
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Ontology
Physiological effect

Health effect:

Disposition

Route of exposure:

Source:

Biological location:

Process

Naturally occurring process:

Role

Biological role:

Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point312 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility22 mg/mLNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
Water Solubility17.3 g/LALOGPS
logP-4ALOGPS
logP-5.8ChemAxon
logS-1.1ALOGPS
pKa (Strongest Acidic)1.79ChemAxon
pKa (Strongest Basic)9.66ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count6ChemAxon
Hydrogen Donor Count4ChemAxon
Polar Surface Area126.64 ŲChemAxon
Rotatable Bond Count7ChemAxon
Refractivity51.57 m³·mol⁻¹ChemAxon
Polarizability22.02 ųChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (4 TMS)splash10-00fr-8950000000-640b4294e37e5a01048dJSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-0f7c-7910000000-91f9f2b2dd44a3cdb276JSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (3 TMS)splash10-00or-1940000000-c0d688e4ea87ff3e03faJSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (4 TMS)splash10-00or-0980000000-7d816de782a902900d0eJSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-00fr-8950000000-640b4294e37e5a01048dJSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-0f7c-7910000000-91f9f2b2dd44a3cdb276JSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-00or-1940000000-c0d688e4ea87ff3e03faJSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-00or-0980000000-7d816de782a902900d0eJSpectraViewer | MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-00di-9410000000-9487e9168e86a2297931JSpectraViewer | MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (2 TMS) - 70eV, Positivesplash10-00dm-9665000000-608a6335880ad1c2519dJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-0089-1980000000-99cb7d1da067e5436b09JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-000i-9200000000-fb776970b6ef36e72725JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-000i-9200000000-fb776970b6ef36e72725JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 10V, Positivesplash10-00fr-0690000000-0b572de3fcbc7e2f13ccJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 20V, Positivesplash10-000t-0900000000-5788192b32aadd177e33JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 30V, Positivesplash10-000b-4900000000-b86ac7de446a762365bdJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 40V, Positivesplash10-000j-9800000000-75ff1bc6e325692a9da9JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 50V, Positivesplash10-00kr-9100000000-6517562dc0f31a85afc8JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-IT (LC/MSD Trap XCT, Agilent Technologies) , Positivesplash10-001i-0900000000-d1628d0a880f1b6e6d90JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-IT (LC/MSD Trap XCT, Agilent Technologies) , Positivesplash10-000i-9000000000-9a2e1e54b77216e2df72JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) , Positivesplash10-00di-0090000000-36678c2f0bf1b01cc9d4JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) 30V, Positivesplash10-05fr-0190000000-e575f57f0d76ef6afa49JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) , Negativesplash10-00e9-0940000000-962ae510f06296b98878JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , negativesplash10-00e9-0940000000-27da1912eac54f485bfaJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00fr-0690000000-82fe2198c98660008c04JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-000t-0900000000-58cceb69cceeff79606cJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-000b-4900000000-5877787c54120dc165c9JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-000j-9800000000-fd29b0fcf62b73831829JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00kr-9100000000-6517562dc0f31a85afc8JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-05di-1930000000-887e3ad7da04e4f1aac9JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-01uc-6900000000-563444ac8ab717997268JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0uki-9700000000-35397d8e2ab2c6582c52JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-00di-0970000000-d0f0a96ca41d1f751c26JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0089-3910000000-22200c974305822456d8JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-008l-9300000000-0dfaab5efe3438889c3cJSpectraViewer | MoNA
1D NMR1H NMR SpectrumNot AvailableJSpectraViewer
1D NMR1H NMR SpectrumNot AvailableJSpectraViewer
1D NMR13C NMR SpectrumNot AvailableJSpectraViewer
2D NMR[1H,13C] 2D NMR SpectrumNot AvailableJSpectraViewer
Biological Properties
Cellular Locations
  • Cytoplasm (predicted from logP)
Biospecimen Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Feces
  • Urine
Tissue Locations
  • Brain
  • Kidney
  • Liver
  • Prostate
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified0.329 (0.150-0.661) uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.0440-0.342 uMAdult (>18 years old)Not SpecifiedNormal details
BloodDetected and Quantified0.17 (0.1 – 0.27) uMChildren (1-13 years old)BothNormal details
BloodDetected and Quantified1.0 (0.3-5.5) uMNewborn (0-30 days old)BothNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified0.126 (0.065 - 0.301) uMAdult (>18 years old)BothNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.024 +/- 0.006 uMChildren (1-13 years old)BothNormal details
FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedNormal details
FecesDetected but not Quantified Adult (>18 years old)Both
Normal
details
UrineDetected and Quantified1.84 (0.39-3.28) umol/mmol creatinineAdult (>18 years old)BothNormal
    details
    UrineDetected and Quantified0.94-2.3 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
    UrineDetected and Quantified14.7 (3.9-20.7) umol/mmol creatinineAdult (>18 years old)Both
    Normal
    details
    UrineDetected and Quantified0.80-1.6 umol/mmol creatinineAdult (>18 years old)MaleNormal details
    UrineDetected and Quantified1.54 ± 1.09 umol/mmol creatinineAdult (>18 years old)BothNormal details
    UrineDetected and Quantified0.35 +/- 0.65 umol/mmol creatinineInfant (0-1 year old)BothNormal details
    Abnormal Concentrations
    BiospecimenStatusValueAgeSexConditionReferenceDetails
    BloodDetected and Quantified0.552 uMChildren (1-13 years old)MaleHypermethioninemia details
    BloodDetected and Quantified10 uMChildren (1-13 years old)FemaleCystathioninuria details
    BloodDetected and Quantified1.56 (0.14 - 4.1) uMAdult (>18 years old)BothFolate Deficiency details
    BloodDetected and Quantified0.82 (0.21 - 2.9) uMAdult (>18 years old)BothCobalamin Deficiency details
    BloodDetected and Quantified0.14 (0.04-0.2) uMChildren (1-13 years old)BothAutism details
    BloodDetected and Quantified1.03 +/- 0.22 uMElderly (>65 years old)BothAlzheimer's disease details
    FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedCrohns disease details
    FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedUlcerative colitis details
    FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedUnclassified IBD details
    UrineDetected and Quantified6.139 umol/mmol creatinineChildren (1-13 years old)Female
    Cystathioninuria
    details
    UrineDetected and Quantified6.897 umol/mmol creatinineChildren (1-13 years old)Female
    Cystathioninuria
    details
    UrineDetected and Quantified182.14 umol/mmol creatinineChildren (1-13 years old)FemaleCystathioninuria details
    UrineDetected and Quantified84.795 umol/mmol creatinineChildren (1-13 years old)FemaleCystathioninuria details
    UrineDetected and Quantified216.623 umol/mmol creatinineChildren (1-13 years old)FemaleCystathioninuria details
    UrineDetected and Quantified381.0 +/- 29.0 umol/mmol creatinineAdult (>18 years old)BothCystathioninuria details
    UrineDetected and Quantified5.3 (1.0-9.6) umol/mmol creatinineAdult (>18 years old)BothCystathioninuria
      • MetaGene: Metabol...
    details
    UrineDetected and Quantified1001.0 (158.0-1843.8) umol/mmol creatinineChildren (1-13 years old)BothGamma-Cystathionase deficiency
      • MetaGene: Metabol...
    details
    UrineDetected and Quantified12.677 +/- 3.531 umol/mmol creatinineChildren (1 - 13 years old)Not Specified
    Eosinophilic esophagitis
      • Mordechai, Hien, ...
    details
    UrineDetected and Quantified1.68 +/- 0.5 umol/mmol creatinineAdult (>18 years old)BothAlzheimer's disease details
    Associated Disorders and Diseases
    Disease References
    Folate deficiency
    1. Stabler SP, Lindenbaum J, Savage DG, Allen RH: Elevation of serum cystathionine levels in patients with cobalamin and folate deficiency. Blood. 1993 Jun 15;81(12):3404-13. [PubMed:8507876 ]
    Vitamin B12 deficiency
    1. Stabler SP, Lindenbaum J, Savage DG, Allen RH: Elevation of serum cystathionine levels in patients with cobalamin and folate deficiency. Blood. 1993 Jun 15;81(12):3404-13. [PubMed:8507876 ]
    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. [PubMed:17031479 ]
    Autism
    1. James SJ, Cutler P, Melnyk S, Jernigan S, Janak L, Gaylor DW, Neubrander JA: Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism. Am J Clin Nutr. 2004 Dec;80(6):1611-7. [PubMed:15585776 ]
    Hypermethioninemia
    1. Baric I, Fumic K, Glenn B, Cuk M, Schulze A, Finkelstein JD, James SJ, Mejaski-Bosnjak V, Pazanin L, Pogribny IP, Rados M, Sarnavka V, Scukanec-Spoljar M, Allen RH, Stabler S, Uzelac L, Vugrek O, Wagner C, Zeisel S, Mudd SH: S-adenosylhomocysteine hydrolase deficiency in a human: a genetic disorder of methionine metabolism. Proc Natl Acad Sci U S A. 2004 Mar 23;101(12):4234-9. Epub 2004 Mar 15. [PubMed:15024124 ]
    Crohn's disease
    1. Kolho KL, Pessia A, Jaakkola T, de Vos WM, Velagapudi V: Faecal and Serum Metabolomics in Paediatric Inflammatory Bowel Disease. J Crohns Colitis. 2017 Mar 1;11(3):321-334. doi: 10.1093/ecco-jcc/jjw158. [PubMed:27609529 ]
    Ulcerative colitis
    1. Kolho KL, Pessia A, Jaakkola T, de Vos WM, Velagapudi V: Faecal and Serum Metabolomics in Paediatric Inflammatory Bowel Disease. J Crohns Colitis. 2017 Mar 1;11(3):321-334. doi: 10.1093/ecco-jcc/jjw158. [PubMed:27609529 ]
    Cystathioninuria
    1. Sugahara K, Ohta J, Takemura M, Kodama H: Determination of cystathionine and perhydro-1,4-thiazepine-3,5-dicarboxylic acid in the urine of a patient with cystathioninuria using column liquid chromatography-mass spectrometry. J Chromatogr. 1992 Sep 2;579(2):318-23. [PubMed:1429979 ]
    2. Espinos C, Garcia-Cazorla A, Martinez-Rubio D, Martinez-Martinez E, Vilaseca MA, Perez-Duenas B, Kozich V, Palau F, Artuch R: Ancient origin of the CTH alelle carrying the c.200C>T (p.T67I) variant in patients with cystathioninuria. Clin Genet. 2010 Dec;78(6):554-9. doi: 10.1111/j.1399-0004.2010.01431.x. [PubMed:20584029 ]
    3. G.Frauendienst-Egger, Friedrich K. Trefz (2017). MetaGene: Metabolic & Genetic Information Center (MIC: http://www.metagene.de). METAGENE consortium.
    Eosinophilic esophagitis
    1. (). Mordechai, Hien, and David S. Wishart. .
    Associated OMIM IDs
    DrugBank IDNot Available
    Phenol Explorer Compound IDNot Available
    FoodDB IDFDB001976
    KNApSAcK IDC00007498
    Chemspider ID388392
    KEGG Compound IDC02291
    BioCyc IDCYSTATHIONINE
    BiGG ID39523
    Wikipedia LinkCystathionine
    METLIN ID39
    PubChem Compound439258
    PDB IDNot Available
    ChEBI ID17482
    References
    Synthesis ReferenceYamagata, Shuzo; Akamatsu, Tsuyoshi; Iwama, Tomonori. Immobilization of Saccharomyces cerevisiae cystathionine gamma-lyase and application of the product to cystathionine synthesis. Applied and Environmental Microbiology (2004), 70(6), 3766-3768.
    Material Safety Data Sheet (MSDS)Download (PDF)
    General References
    1. Kraus JP, Janosik M, Kozich V, Mandell R, Shih V, Sperandeo MP, Sebastio G, de Franchis R, Andria G, Kluijtmans LA, Blom H, Boers GH, Gordon RB, Kamoun P, Tsai MY, Kruger WD, Koch HG, Ohura T, Gaustadnes M: Cystathionine beta-synthase mutations in homocystinuria. Hum Mutat. 1999;13(5):362-75. [PubMed:10338090 ]
    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. doi: 10.1038/nature07762. [PubMed:19212411 ]
    3. 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. [PubMed:2026685 ]
    4. Ricci G, Santoro L, Achilli M, Matarese RM, Nardini M, Cavallini D: Similarity of the oxidation products of L-cystathionine by L-amino acid oxidase to those excreted by cystathioninuric patients. J Biol Chem. 1983 Sep 10;258(17):10511-7. [PubMed:6885789 ]
    5. Herrmann W, Schorr H, Bodis M, Knapp JP, Muller A, Stein G, Geisel J: Role of homocysteine, cystathionine and methylmalonic acid measurement for diagnosis of vitamin deficiency in high-aged subjects. Eur J Clin Invest. 2000 Dec;30(12):1083-9. [PubMed:11122323 ]
    6. Stabler SP, Lindenbaum J, Savage DG, Allen RH: Elevation of serum cystathionine levels in patients with cobalamin and folate deficiency. Blood. 1993 Jun 15;81(12):3404-13. [PubMed:8507876 ]
    7. Lefauconnier JM, Portemer C, Chatagner F: Free amino acids and related substances in human glial tumours and in fetal brain: comparison with normal adult brain. Brain Res. 1976 Nov 19;117(1):105-13. [PubMed:186155 ]
    8. James SJ, Cutler P, Melnyk S, Jernigan S, Janak L, Gaylor DW, Neubrander JA: Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism. Am J Clin Nutr. 2004 Dec;80(6):1611-7. [PubMed:15585776 ]
    9. Shimizu H, Kakimoto Y, Sano I: A method of determination of cystathionine and its distribution in human brain. J Neurochem. 1966 Feb;13(2):65-73. [PubMed:5936154 ]
    10. Haurani FI, Hall CA, Rubin R: Megaloblastic anemia as a result of an abnormal transcobalamin II (Cardeza). J Clin Invest. 1979 Nov;64(5):1253-9. [PubMed:500809 ]
    11. Wisniewski K, Sturman JA, Devine E, Brown WT, Rudelli R, Wisniewski HM: Cystathionine disappearance with neuronal loss: a possible neuronal marker. Neuropediatrics. 1985 Aug;16(3):126-30. [PubMed:4047345 ]

    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-Cystathionine + Water → L-Cysteine + Ammonia + 2-Ketobutyric aciddetails
    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 + Homocysteine → L-Cystathionine + Waterdetails