[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a peptide zwitterion obtained by transfer of a proton from the carboxy to the amino terminus of Leu-enkephalin. Major species at pH 7.3. It is a tautomer of a Leu-enkephalin."}, {"from": "gpt", "value": "[C][C][Branch1][C][C][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][N][C][=Branch1][C][=O][C@H1][Branch1][#Branch2][C][C][=C][C][=C][C][=C][Ring1][=Branch1][N][C][=Branch1][C][=O][C][N][C][=Branch1][C][=O][C][N][C][=Branch1][C][=O][C@H1][Branch1][=N][C][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][NH3+1]"}]