MetaCyc Compound: L-cystine

Superclasses: an amino acid or its derivative an amino acid an alpha amino acid a non-standard alpha amino acid cystine
an amino acid or its derivative an amino acid an alpha amino acid a non-standard alpha amino acid

Chemical Formula: C6H12N2O4S2

Molecular Weight: 240.29 Daltons

Monoisotopic Molecular Weight: 240.02384826399998 Daltons

L-cystine compound structure

SMILES: C(C(C(=O)[O-])[N+])SSCC(C([O-])=O)[N+]

InChI: 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


Unification Links: CAS:24645-67-8 , ChEBI:35492 , HMDB:HMDB00192 , KEGG:C01420 , MetaboLights:MTBLC35491 , PubChem:24798687

Standard Gibbs Free Energy of Change Formation (ΔfG in kcal/mol): -36.046562 Inferred by computational analysis [Latendresse13]

Reactions known to consume the compound:

Not in pathways:
L-cystine + H2O → thiocysteine + pyruvate + ammonium
a reduced thioredoxin + L-cystine → an oxidized thioredoxin + 2 L-cysteine

Reactions known to produce the compound:

Not in pathways:
amino acids(n) + H2O → amino acids(n-1) + an α amino acid
an α amino acid ester + H2O → an alcohol + an α amino acid + H+
a protein + H2O → a protein + an α amino acid

In Reactions of unknown directionality:

Not in pathways:
2 L-cysteine + NAD+ = L-cystine + NADH + H+
L-cystine = 2-aminoprop-2-enoate + thiocysteine + H+
L-cystine + 2 glutathione = glutathione disulfide + 2 L-cysteine

Not in pathways:
a 5-L-glutamyl-[peptide] + an amino acid = a 5-L-glutamyl-amino acid + a peptide

In Transport reactions:
L-glutamate[cytosol] + L-cystine[extracellular space]L-cystine[cytosol] + L-glutamate[extracellular space] ,
L-cystine[periplasmic space] + ATP + H2O → L-cystine[cytosol] + ADP + phosphate + H+ ,
L-cystine[cytosol]L-cystine[periplasmic space] ,
cystine[cytosol]cystine[periplasmic space]

Enzymes inhibited by L-cystine, sorted by the type of inhibition, are:

Inhibitor (Competitive) of: diaminopimelate decarboxylase [White65]

Inhibitor (Mechanism unknown) of: aspartate semialdehyde dehydrogenase [Alvarez04]

This compound has been characterized as an alternative substrate of the following enzymes: L-cystathione β-lyase , cystathionine β-lyase , L-cysteine-S-conjugate thiol-lyase (deaminating; pyruvate-forming)


Alvarez04: Alvarez E, Ramon F, Magan C, Diez E (2004). "L-cystine inhibits aspartate-beta-semialdehyde dehydrogenase by covalently binding to the essential 135Cys of the enzyme." Biochim Biophys Acta 1696(1);23-9. PMID: 14726201

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

White65: White PJ, Kelly B (1965). "Purification and properties of diaminopimelate decarboxylase from Escherichia coli." Biochem J 96;75-84. PMID: 14343156

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Wed Apr 1, 2015, biocyc13.