SMILES: C1=NC(=C(N1)C[C@@H](C(=O)[O-])[NH3+])S(=O)C[C@@H](C(=O)[O-])[NH3+]
Description: The molecule is an L-alpha-amino acid zwitterion formed from S-(5-histidyl)cysteine sulfoxide by transfer of protons from the two carboxy to the two amino grousp; major species at pH 7.3. It derives from a L-histidine zwitterion and a L-cysteine zwitterion. It is a tautomer of a S-(5-histidyl)cysteine sulfoxide.