[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][N][C][=N][C][=C][Ring1][Branch1][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N]"}, {"from": "gpt", "value": "The molecule is a post-translationally modified amino acid found in actin and myosin and a derivative of histidine that has a methyl group bound to the nitrogen at position 3. Urinary levels of 3-methylhistidine are proportional to protein turnover and can be an indicator for myofibrillar protein degradation or a high protein diet."}]