[{"from": "human", "value": "What can you tell me about this molecule? [C][Branch1][S][C][Branch1][N][C][=Branch1][C][=O][N][C][C][=Branch1][C][=O][O-1][NH3+1][S][S][C][C][Branch1][N][C][=Branch1][C][=O][N][C][C][=Branch1][C][=O][O-1][NH3+1]"}, {"from": "gpt", "value": "The molecule is a peptide zwitterion obtained by transfer of two protons from the carboxy to the amino groups of Cys-Gly disulfide; major species at pH 7.3. It is a tautomer of a Cys-Gly disulfide."}]