Record Information
Version 1.0
Update Date 1/22/2018 12:54:54 PM
Metabolite IDPAMDB000488
Name: Selenocysteine
Description:Selenocysteine is considered to be the 21st proteinogenic amino acid. It exists naturally in all kingdoms of life as a building block of selenoproteins. Selenocysteine is a cysteine analogue with a selenium-containing selenol group in place of the sulfur-containing thiol group. Selenocysteine is present in several enzymes (for example glutathione peroxidases, tetraiodothyronine 5' deiodinases, thioredoxin reductases, formate dehydrogenases, glycine reductases,
  • (2R)-2-amino-3-selanylpropanoate
  • (2R)-2-amino-3-selanylpropanoic acid
  • 3-Seleno-alanine
  • 3-Selenoalanine
  • 3-Selenyl-L-Alanine
  • L-Selenocystein
  • L-Selenocysteine
  • L-Selenozystein
  • U
Chemical Formula: C3H7NO2Se
Average Molecular Weight: 168.05
Monoisotopic Molecular Weight: 168.964200301
CAS number: 3614-08-2
IUPAC Name:(2R)-2-amino-3-selanylpropanoic acid
Traditional IUPAC Name: L-selenocysteine
Chemical Taxonomy
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.
Kingdom Organic compounds
Super ClassOrganic acids and derivatives
Class Carboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct Parent L-alpha-amino acids
Alternative Parents
  • L-alpha-amino acid
  • Monocarboxylic acid or derivatives
  • Carboxylic acid
  • Hydrocarbon derivative
  • Selenol
  • Primary amine
  • Organoselenium compound
  • Organooxygen compound
  • Organonitrogen compound
  • Primary aliphatic amine
  • Carbonyl group
  • Amine
  • Aliphatic acyclic compound
Molecular Framework Aliphatic acyclic compounds
External Descriptors
Physical Properties
State: Solid
Melting point: Not Available
Experimental Properties:
Predicted Properties
Water Solubility325.0 mg/mLALOGPS
pKa (Strongest Acidic)1.27ChemAxon
pKa (Strongest Basic)8.42ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area63.32 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity33.45 m3·mol-1ChemAxon
Polarizability10.67 Å3ChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Biological Properties
Cellular Locations: Cytoplasm
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-MSNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-01b9-0900000000-fadd5a69b2b225d034acView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-01b9-0900000000-8fe6412cebc1ca99fe59View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-00dl-5900000000-2408222e037ff9db752aView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-014i-0900000000-91ba91d891f89ff1fc23View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-00kk-6900000000-67c579b8ba30e155bcb3View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-00di-9200000000-0b58b77f13cec3df121dView in MoNA
  • Blotcky AJ, Ebrahim A, Rack EP: Determination of selenium metabolites in biological fluids using instrumental and molecular neutron activation analysis. Anal Chem. 1988 Dec 15;60(24):2734-7. Pubmed: 3245598
  • Chu FF, Esworthy RS, Doroshow JH, Doan K, Liu XF: Expression of plasma glutathione peroxidase in human liver in addition to kidney, heart, lung, and breast in humans and rodents. Blood. 1992 Jun 15;79(12):3233-8. Pubmed: 1339300
  • Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114. Pubmed: 22080510
  • Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. Pubmed: 21097882
  • Mostert V, Wolff S, Dreher I, Kohrle J, Abel J: Identification of an element within the promoter of human selenoprotein P responsive to transforming growth factor-beta. Eur J Biochem. 2001 Dec;268(23):6176-81. Pubmed: 11733012
  • Rooseboom M, Vermeulen NP, Andreadou I, Commandeur JN: Evaluation of the kinetics of beta-elimination reactions of selenocysteine Se-conjugates in human renal cytosol: possible implications for the use as kidney selective prodrugs. J Pharmacol Exp Ther. 2000 Aug;294(2):762-9. Pubmed: 10900258
  • Sun QA, Su D, Novoselov SV, Carlson BA, Hatfield DL, Gladyshev VN: Reaction mechanism and regulation of mammalian thioredoxin/glutathione reductase. Biochemistry. 2005 Nov 8;44(44):14528-37. Pubmed: 16262253
  • Utomo A, Jiang X, Furuta S, Yun J, Levin DS, Wang YC, Desai KV, Green JE, Chen PL, Lee WH: Identification of a novel putative non-selenocysteine containing phospholipid hydroperoxide glutathione peroxidase (NPGPx) essential for alleviating oxidative stress generated from polyunsaturated fatty acids in breast cancer cells. J Biol Chem. 2004 Oct 15;279(42):43522-9. Epub 2004 Aug 4. Pubmed: 15294905
  • van der Werf, M. J., Overkamp, K. M., Muilwijk, B., Coulier, L., Hankemeier, T. (2007). "Microbial metabolomics: toward a platform with full metabolome coverage." Anal Biochem 370:17-25. Pubmed: 17765195
  • Winder, C. L., Dunn, W. B., Schuler, S., Broadhurst, D., Jarvis, R., Stephens, G. M., Goodacre, R. (2008). "Global metabolic profiling of Escherichia coli cultures: an evaluation of methods for quenching and extraction of intracellular metabolites." Anal Chem 80:2939-2948. Pubmed: 18331064
  • Zimmermann MB, Kohrle J: The impact of iron and selenium deficiencies on iodine and thyroid metabolism: biochemistry and relevance to public health. Thyroid. 2002 Oct;12(10):867-78. Pubmed: 12487769
  • Zinoni, F., Birkmann, A., Stadtman, T. C., Bock, A. (1986). "Nucleotide sequence and expression of the selenocysteine-containing polypeptide of formate dehydrogenase (formate-hydrogen-lyase-linked) from Escherichia coli." Proc Natl Acad Sci U S A 83:4650-4654. Pubmed: 2941757
Synthesis Reference: Not Available
Material Safety Data Sheet (MSDS) Not Available
External Links:
Pubchem Compound ID6326983
Kegg IDC05688
ChemSpider ID23436
Ligand ExpoCSE


General function:
Involved in cysteine biosynthetic process from serine
Specific function:
O(3)-acetyl-L-serine + H(2)S = L-cysteine + acetate
Gene Name:
Locus Tag:
Molecular weight:
34.3 kDa
O(3)-acetyl-L-serine + H(2)S = L-cysteine + acetate.
3-chloro-L-alanine + thioglycolate = S-carboxymethyl-L-cysteine + chloride.
General function:
Involved in cysteine biosynthetic process from serine
Specific function:
Two cysteine synthase enzymes are found. Both catalyze the same reaction. Cysteine synthase B can also use thiosulfate in place of sulfide to give cysteine thiosulfonate as a product
Gene Name:
Locus Tag:
Molecular weight:
32.4 kDa
O(3)-acetyl-L-serine + H(2)S = L-cysteine + acetate.


General function:
Involved in nucleotide binding
Specific function:
Probably part of a binding-protein-dependent transport system yecCS for an amino acid. Probably responsible for energy coupling to the transport system
Gene Name:
Locus Tag:
Molecular weight:
28.4 kDa