L-Cysteine

Cysteine is sulphur - containing nonessential amino acid. In peptides and proteins, the sulfur atoms of two cysteine molecules are bonded to each other to make cystine, another amino acid.

IUPAC Name: (2R)-2-amino-3-sulfanylpropanoic acid
Symbol: Cys or C
Molecular Weight: 121.15818 g/mol
Molecular Formula: C3H7NO2S
Canonical SMILES: C(C(C(=O)O)N)S
Isomeric SMILES: C([C@@H](C(=O)O)N)S
InChIKey Identifier: XUJNEKJLAYXESH-SNQCPAJUDK
CAS Number: 52-90-4
MDL Number: MFCD00064306
Melting point: 220 °C
Solubility in water: 280 g/L (25 °C)
2D Molfile: Get the molfile
3D PDB file: Get the PDB file
Other names: (R)-2-Amino-3-mercaptopropionic acid; beta-Mercaptoalanine; Thioserine; CySH; 3-Mercapto-L-alanine

Load 3D Structure of Cysteine

As a key constituent of glutathione, cysteine has many important physiological functions. Glutathione, formed from cysteine, glutamic acid, and glycine, is found in all human tissues. The antioxidant activity of glutathione is attributed specifically to the presence of cysteine in the compound.

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