ACMSD (α-Amino-β-methyl-α-succinyl-CoA deaminase) is an enzyme involved in the tryptophan metabolism pathway, converting α-Amino-β-methyl-α-succinyl-CoA to α-Amino-β-methyl-γ-oxovaleric acid. It consists of multiple functional domains and is primarily located in the mitochondria. ACMSD plays a crucial role in regulating neurotransmitters and the synthesis of NAD+ precursors. Its expression is tissue-specific, and mutations or dysregulation in its gene are associated with various diseases, including neurodegenerative diseases, cardiovascular diseases, and metabolic disorders. The activity and expression level of ACMSD affect the balance of the tryptophan metabolism pathway, thereby influencing the physiological and pathological states of cells.