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Record Information
Version3.6
Creation Date2005-11-16 15:48:42 UTC
Update Date2014-09-22 19:38:47 UTC
HMDB IDHMDB00742
Secondary Accession Numbers
  • HMDB00165
Metabolite Identification
Common NameHomocysteine
DescriptionHomocysteine is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with increased incidence of cardiovascular disease and Alzheimer's disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. Pyridoxal, folic acid, riboflavin, and Vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 %, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocysteinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD. (PMID 17136938 , 15630149 ).
Structure
Thumb
Synonyms
  1. (+-)-homocysteine
  2. (S)-2-amino-4-mercapto-Butanoate
  3. (S)-2-amino-4-mercapto-Butanoic acid
  4. 2-Amino-4-mercapto-Butanoate
  5. 2-Amino-4-mercapto-Butanoic acid
  6. 2-Amino-4-mercapto-Butyric acid
  7. 2-Amino-4-mercapto-DL-Butyrate
  8. 2-Amino-4-mercapto-DL-Butyric acid
  9. 2-Amino-4-mercaptobutyric acid
  10. 2-Amino-4-sulfanylbutanoate
  11. 2-Amino-4-sulfanylbutanoic acid
  12. D,L-Homocysteine
  13. DL-2-amino-4-mercapto-Butyric acid
  14. DL-2-Amino-4-mercaptobutyric acid
  15. DL-Homocysteine
  16. DL-homocysteine (free base)
  17. HCY
  18. Homo-CYS
  19. Homocysteine
  20. L-2-Amino-4-mercapto-Butyric acid
  21. L-Homocysteine
  22. Usaf B-12
Chemical FormulaC4H9NO2S
Average Molecular Weight135.185
Monoisotopic Molecular Weight135.035399227
IUPAC Name2-amino-4-sulfanylbutanoic acid
Traditional IUPAC Namehomocysteine
CAS Registry Number454-29-5
SMILES
NC(CCS)C(O)=O
InChI Identifier
InChI=1S/C4H9NO2S/c5-3(1-2-8)4(6)7/h3,8H,1-2,5H2,(H,6,7)
InChI KeyFFFHZYDWPBMWHY-UHFFFAOYSA-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
  • amino acid 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 Glycine, serine and threonine metabolism
  • Component of Methionine metabolism
  • Component of Selenoamino acid metabolism
  • Component of Ubiquinone biosynthesis
  • Essential amino acid
  • Waste products
ApplicationNot Available
Cellular locations
  • Cytoplasm (predicted from logP)
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point232 - 233 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility148 mg/mLNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
Water Solubility14.8 g/LALOGPS
logP-2.3ALOGPS
logP-2.6ChemAxon
logS-0.96ALOGPS
pKa (Strongest Acidic)2.46ChemAxon
pKa (Strongest Basic)9.41ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area63.32ChemAxon
Rotatable Bond Count3ChemAxon
Refractivity32.94ChemAxon
Polarizability13.44ChemAxon
Spectra
SpectraGC-MSMS/MS1D NMR2D NMR
Biological Properties
Cellular Locations
  • Cytoplasm (predicted from logP)
Biofluid Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Urine
Tissue Location
  • Adipose Tissue
  • Artery
  • Brain
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Muscle
  • Nerve Cells
  • Neuron
  • Pancreas
  • Placenta
  • Platelet
Pathways
NameSMPDB LinkKEGG Link
Betaine MetabolismSMP00123map00260
Catecholamine BiosynthesisSMP00012map00350
Glycine and Serine MetabolismSMP00004map00260
Homocysteine DegradationSMP00455Not Available
Methionine MetabolismSMP00033map00270
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified9.4 (7.3-16.2) uMAdult (>18 years old)Not SpecifiedNormal details
BloodDetected and Quantified9.8 (7.6-14.9) uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified5.00 +/- 1.6 uMInfant (0-1 year old)BothNormal details
BloodDetected and Quantified10.4 +/- 2.3 uMChildren (1-13 years old)BothNormal details
BloodDetected and Quantified9.00 +/- 2.2 uMAdolescent (13-18 years old)BothNormal details
BloodDetected and Quantified9.00 +/- 2.00 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified9.99 +/- 1.04 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified6.00 (4.8-7.40) uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified9.11 +/- 2.99 uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.09 (0.06-0.16) uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified20.7 +/- 1.7 uMElderly (>65 years old)BothNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.057 +/- 0.035 uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.12 +/- 0.08 uMElderly (>65 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.15 +/- 0.07 uMAdult (>18 years old)Not SpecifiedNormal details
UrineDetected and Quantified1.1 (0.6-1.74) umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified2.00 +/- 1.65 umol/mmol creatinineInfant (0-1 year old)MaleNormal details
UrineDetected and Quantified1.5 +/- 0.69 umol/mmol creatinineChildren (1-13 years old)MaleNormal details
UrineDetected and Quantified1.78 +/- 0.73 umol/mmol creatinineAdolescent (13-18 years old)MaleNormal details
UrineDetected and Quantified1.95 +/- 1.47 umol/mmol creatinineAdult (>18 years old)MaleNormal details
Abnormal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified12.9 (8.2-28.2) uMAdult (>18 years old)Not SpecifiedDementia (Alzheimer's and non-Alzheimer's) details
BloodDetected and Quantified10.7 (7.6-14.4) uMAdult (>18 years old)Not SpecifiedMultiple sclerosis details
BloodDetected and Quantified10.2 (7.0-17.4) uMAdult (>18 years old)Not SpecifiedStroke details
BloodDetected and Quantified11.9 (7.0-19.1) uMAdult (>18 years old)Not SpecifiedPeripheral neuropathy details
BloodDetected and Quantified21.0 (18.5-25.7) uMAdult (>18 years old)BothChronic renal failure details
BloodDetected and Quantified25.5 (16.9-32.6) uMAdult (>18 years old)BothContinuous ambulatory peritoneal dialysis (CAPD) details
BloodDetected and Quantified29.7 (25.7-38.2) uMAdult (>18 years old)BothHemodialysis details
BloodDetected and Quantified68.80 +/- 15.53 uMAdult (>18 years old)Bothuremia details
BloodDetected and Quantified12.5 +/- 5.0 uMAdult (>18 years old)Both
Sickle cell anemia
details
BloodDetected and Quantified125.00 (50.00-200.00) uMChildren (1-13 years old)BothCystathionine beta-synthase deficiency details
BloodDetected and Quantified9.22 +/- 1.81 uMAdult (>18 years old)Not SpecifiedCruetzfeldt-Jakob disease details
BloodDetected and Quantified15.1 uMAdult (>18 years old)BothParkinson's disease details
BloodDetected and Quantified13.94 +/- 3.47 uMAdult (>18 years old)BothAmyotrophic lateral sclerosis details
BloodDetected and Quantified15.75 +/- 5.75 uMAdult (>18 years old)BothProgressive supranuclear palsy details
Cerebrospinal Fluid (CSF)Detected and Quantified0.08 (0.05-0.16) uMAdult (>18 years old)Not SpecifiedMultiple sclerosis details
Cerebrospinal Fluid (CSF)Detected and Quantified0.08 (0.06-0.15) uMAdult (>18 years old)Not SpecifiedStroke details
Cerebrospinal Fluid (CSF)Detected and Quantified0.11 (0.07-0.18) uMAdult (>18 years old)Not SpecifiedPeripheral neuropathy details
Cerebrospinal Fluid (CSF)Detected and Quantified0.216 +/- 0.122 uMAdult (>18 years old)Not SpecifiedAlzheimer's disease details
Cerebrospinal Fluid (CSF)Detected and Quantified0.12 +/- 0.062 uMElderly (>65 years old)Not SpecifiedAlzheimer's disease details
Cerebrospinal Fluid (CSF)Detected and Quantified0.10 (0.06–0.32) uMAdult (>18 years old)Not SpecifiedDementia (Alzheimer's and non-Alzheimer's) details
Cerebrospinal Fluid (CSF)Detected and Quantified14.2 +/- 1.7 uMElderly (>65 years old)Not SpecifiedAlzheimer's disease details
Cerebrospinal Fluid (CSF)Detected and Quantified0.13 +/- 0.03 uMAdult (>18 years old)Not SpecifiedCruetzfeldt-Jakob disease details
Associated Disorders and Diseases
Disease References
Alzheimer's disease
  1. Selley ML, Close DR, Stern SE: The effect of increased concentrations of homocysteine on the concentration of (E)-4-hydroxy-2-nonenal in the plasma and cerebrospinal fluid of patients with Alzheimer's disease. Neurobiol Aging. 2002 May-Jun;23(3):383-8. Pubmed: 11959400
  2. Serot JM, Barbe F, Arning E, Bottiglieri T, Franck P, Montagne P, Nicolas JP: Homocysteine and methylmalonic acid concentrations in cerebrospinal fluid: relation with age and Alzheimer's disease. J Neurol Neurosurg Psychiatry. 2005 Nov;76(11):1585-7. Pubmed: 16227558
Chronic renal failure
  1. McGregor DO, Dellow WJ, Lever M, George PM, Robson RA, Chambers ST: Dimethylglycine accumulates in uremia and predicts elevated plasma homocysteine concentrations. Kidney Int. 2001 Jun;59(6):2267-72. Pubmed: 11380830
Continuous ambulatory peritoneal dialysis
  1. McGregor DO, Dellow WJ, Lever M, George PM, Robson RA, Chambers ST: Dimethylglycine accumulates in uremia and predicts elevated plasma homocysteine concentrations. Kidney Int. 2001 Jun;59(6):2267-72. Pubmed: 11380830
Creutzfeldt-Jakob disease
  1. Bleich S, Otto M, Zerr I, Kropp S, Kretzschmar HA, Wiltfang J: Creutzfeldt-Jakob disease and homocysteine levels in plasma and cerebrospinal fluid. Gerontology. 2005 Mar-Apr;51(2):142-4. Pubmed: 15711082
  2. [No authors listed] Pubmed: 115711082
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
Hemodialysis
  1. McGregor DO, Dellow WJ, Lever M, George PM, Robson RA, Chambers ST: Dimethylglycine accumulates in uremia and predicts elevated plasma homocysteine concentrations. Kidney Int. 2001 Jun;59(6):2267-72. Pubmed: 11380830
Homocystinuria
  1. MetaGene
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
Parkinson's disease
  1. Levin J, Botzel K, Giese A, Vogeser M, Lorenzl S: Elevated levels of methylmalonate and homocysteine in Parkinson's disease, progressive supranuclear palsy and amyotrophic lateral sclerosis. Dement Geriatr Cogn Disord. 2010 Jul;29(6):553-9. Epub 2010 Jul 3. Pubmed: 20606437
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
Sickle cell anemia
  1. van der Dijs FP, Schnog JJ, Brouwer DA, Velvis HJ, van den Berg GA, Bakker AJ, Duits AJ, Muskiet FD, Muskiet FA: Elevated homocysteine levels indicate suboptimal folate status in pediatric sickle cell patients. Am J Hematol. 1998 Nov;59(3):192-8. Pubmed: 9798656
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 IDNot Available
DrugBank Metabolite IDDBMET00508
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB001491
KNApSAcK IDC00001365
Chemspider ID757
KEGG Compound IDC00155
BioCyc IDHOMO-CYS
BiGG ID45588
Wikipedia LinkHomocysteine
NuGOwiki LinkHMDB00742
Metagene LinkHMDB00742
METLIN ID3256
PubChem Compound778
PDB IDNot Available
ChEBI ID17230
References
Synthesis ReferenceKarrenbauer, Michael; Kleemann, Axel; Luessling, Theodor; Schaefer, Fritz. D,L-Homocysteine (I). Ger. (1984), 4 pp.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Selley ML, Close DR, Stern SE: The effect of increased concentrations of homocysteine on the concentration of (E)-4-hydroxy-2-nonenal in the plasma and cerebrospinal fluid of patients with Alzheimer's disease. Neurobiol Aging. 2002 May-Jun;23(3):383-8. Pubmed: 11959400
  2. Yu CK, Lakasing L, Papageorghiou AT, Spencer K, Nicolaides KH: Uterine artery Doppler and mid-trimester maternal plasma homocysteine in subsequent pre-eclampsia. J Matern Fetal Neonatal Med. 2004 Aug;16(2):134-9. Pubmed: 15512726
  3. Giladi N, Mordechovich M, Gruendlinger L, Shabtai H, Merims D, Naor S, Baltadzhieva R, Hausdorff JM, Gur AY, Bornstein NM: "Brain Screen": A self-referral, screening program for strokes, falls and dementia risk factors. J Neurol. 2006 Mar;253(3):307-15. Epub 2005 Oct 10. Pubmed: 16208527
  4. Terzolo M, Allasino B, Bosio S, Brusa E, Daffara F, Ventura M, Aroasio E, Sacchetto G, Reimondo G, Angeli A, Camaschella C: Hyperhomocysteinemia in patients with Cushing's syndrome. J Clin Endocrinol Metab. 2004 Aug;89(8):3745-51. Pubmed: 15292300
  5. Laxdal E, Eide GE, Amundsen SR, Dregelid EB, Pedersen G, Jonung T, Aune S: Homocysteine levels, haemostatic risk factors and restenosis after carotid thrombendarterectomy. Eur J Vasc Endovasc Surg. 2004 Sep;28(3):323-8. Pubmed: 15288638
  6. Akoglu B, Wondra K, Caspary WF, Faust D: Determinants of fasting total serum homocysteine levels in liver transplant recipients. Exp Clin Transplant. 2006 Jun;4(1):462-6. Pubmed: 16827644
  7. Krantz JS, Mack WJ, Hodis HN, Liu CR, Liu CH, Kaufman FR: Early onset of subclinical atherosclerosis in young persons with type 1 diabetes. J Pediatr. 2004 Oct;145(4):452-7. Pubmed: 15480366
  8. Serot JM, Barbe F, Arning E, Bottiglieri T, Franck P, Montagne P, Nicolas JP: Homocysteine and methylmalonic acid concentrations in cerebrospinal fluid: relation with age and Alzheimer's disease. J Neurol Neurosurg Psychiatry. 2005 Nov;76(11):1585-7. Pubmed: 16227558
  9. Hershcovici T, Schechner V, Orlin J, Harell D, Beigel Y: Effect of different LDL-apheresis methods on parameters involved in atherosclerosis. J Clin Apher. 2004;19(2):90-7. Pubmed: 15274202
  10. Muller T, Renger K, Kuhn W: Levodopa-associated increase of homocysteine levels and sural axonal neurodegeneration. Arch Neurol. 2004 May;61(5):657-60. Pubmed: 15148140
  11. Eskes TK: Homocysteine and human reproduction. Clin Exp Obstet Gynecol. 2000;27(3-4):157-67. Pubmed: 11214939
  12. Winkelmayer WC, Kramar R, Curhan GC, Chandraker A, Endler G, Fodinger M, Horl WH, Sunder-Plassmann G: Fasting plasma total homocysteine levels and mortality and allograft loss in kidney transplant recipients: a prospective study. J Am Soc Nephrol. 2005 Jan;16(1):255-60. Epub 2004 Nov 24. Pubmed: 15563562
  13. Park BH, Kim YJ, Park JS, Lee HY, Ha EH, Min JW, Park HS: [Folate and homocysteine levels during pregnancy affect DNA methylation in human placenta] J Prev Med Pub Health. 2005 Nov;38(4):437-42. Pubmed: 16358830
  14. Hossain GS, van Thienen JV, Werstuck GH, Zhou J, Sood SK, Dickhout JG, de Koning AB, Tang D, Wu D, Falk E, Poddar R, Jacobsen DW, Zhang K, Kaufman RJ, Austin RC: TDAG51 is induced by homocysteine, promotes detachment-mediated programmed cell death, and contributes to the cevelopment of atherosclerosis in hyperhomocysteinemia. J Biol Chem. 2003 Aug 8;278(32):30317-27. Epub 2003 May 8. Pubmed: 12738777
  15. Schafer SA, Mussig K, Stefan N, Haring HU, Fritsche A, Balletshofer BM: Plasma homocysteine concentrations in young individuals at increased risk of type 2 diabetes are associated with subtle differences in glomerular filtration rate but not with insulin resistance. Exp Clin Endocrinol Diabetes. 2006 Jun;114(6):306-9. Pubmed: 16868889
  16. Tchantchou F: Homocysteine increase folate oxidative brain homocysteine metabolism and various consequences of folate deficiency. J Alzheimers Dis. 2006 Aug;9(4):421-7. Pubmed: 16917151
  17. Siroka R, Trefil L, Rajdl D, Racek J, Rusnakova H, Cibulka R, Eiselt J, Filipovsky J: Asymmetric dimethylarginine, homocysteine and renal function--is there a relation? Clin Chem Lab Med. 2005;43(10):1147-50. Pubmed: 16197312
  18. Onalan R, Onalan G, Gunenc Z, Karabulut E: Combining 2nd-trimester maternal serum homocysteine levels and uterine artery Doppler for prediction of preeclampsia and isolated intrauterine growth restriction. Gynecol Obstet Invest. 2006;61(3):142-8. Epub 2005 Dec 20. Pubmed: 16374017
  19. Robinson G, Narasimhan S, Weatherall M, Beasley R: Raised plasma homocysteine levels in alcoholism: increasing the risk of heart disease and dementia? N Z Med J. 2005 Jun 3;118(1216):U1490. Pubmed: 15937525
  20. Gulsen M, Yesilova Z, Bagci S, Uygun A, Ozcan A, Ercin CN, Erdil A, Sanisoglu SY, Cakir E, Ates Y, Erbil MK, Karaeren N, Dagalp K: Elevated plasma homocysteine concentrations as a predictor of steatohepatitis in patients with non-alcoholic fatty liver disease. J Gastroenterol Hepatol. 2005 Sep;20(9):1448-55. Pubmed: 16105135
  21. Joubert LM, Manore MM: Exercise, nutrition, and homocysteine. Int J Sport Nutr Exerc Metab. 2006 Aug;16(4):341-61. Pubmed: 17136938
  22. Brosnan JT: Homocysteine and cardiovascular disease: interactions between nutrition, genetics and lifestyle. Can J Appl Physiol. 2004 Dec;29(6):773-80. Pubmed: 15630149

Enzymes

General function:
Involved in cobalamin binding
Specific function:
Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate (By similarity).
Gene Name:
MTR
Uniprot ID:
Q99707
Molecular weight:
140525.91
Reactions
5-Methyltetrahydrofolic acid + Homocysteine → Tetrahydrofolic acid + L-Methioninedetails
General function:
Involved in zinc ion binding
Specific function:
Involved in the regulation of homocysteine metabolism. Converts betaine and homocysteine to dimethylglycine and methionine, respectively. This reaction is also required for the irreversible oxidation of choline.
Gene Name:
BHMT
Uniprot ID:
Q93088
Molecular weight:
44998.205
Reactions
Trimethylammonioacetate + Homocysteine → Dimethylglycine + L-Methioninedetails
General function:
Involved in adenosylhomocysteinase activity
Specific function:
Not Available
Gene Name:
AHCYL2
Uniprot ID:
Q96HN2
Molecular weight:
66592.445
Reactions
S-Adenosylhomocysteine + Water → Homocysteine + Adenosinedetails
General function:
Involved in adenosylhomocysteinase activity
Specific function:
Adenosylhomocysteine is a competitive inhibitor of S-adenosyl-L-methionine-dependent methyl transferase reactions; therefore adenosylhomocysteinase may play a key role in the control of methylations via regulation of the intracellular concentration of adenosylhomocysteine.
Gene Name:
AHCY
Uniprot ID:
P23526
Molecular weight:
47715.715
Reactions
S-Adenosylhomocysteine + Water → Homocysteine + Adenosinedetails
General function:
Involved in adenosylhomocysteinase activity
Specific function:
Not Available
Gene Name:
AHCYL1
Uniprot ID:
O43865
Molecular weight:
53753.0
Reactions
S-Adenosylhomocysteine + Water → Homocysteine + Adenosinedetails
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
General function:
Involved in zinc ion binding
Specific function:
Involved in the regulation of homocysteine metabolism. Converts homocysteine to methionine using S-methylmethionine (SMM) as a methyl donor.
Gene Name:
BHMT2
Uniprot ID:
Q9H2M3
Molecular weight:
33166.69
Reactions
Trimethylammonioacetate + Homocysteine → Dimethylglycine + L-Methioninedetails