[{"from": "human", "value": "Provide a brief overview of this molecule. [C][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}, {"from": "gpt", "value": "The molecule is an S-alkyl-L-cysteine zwitterion obtained by transfer of a proton from the carboxy to the amino group of S-methylcysteine; major species at pH 7.3. It is a tautomer of a S-methylcysteine."}]