Tyrosine hydroxylase and Aromatic L-amino acid decarboxylase (TH and AADC)

"Dopamine precursor conversion" refers to the *biochemical process* by which enzymes convert dietary or endogenous amino acids to dopamine. The two key steps are: - The conversion of L-tyrosine to L-DOPA by **tyrosine hydroxylase**, the rate-limiting enzyme in catecholamine biosynthesis[1][5][3]. - The conversion of L-DOPA to dopamine by **aromatic L-amino acid decarboxylase (AADC)**[1][2][3]. These enzymes are key therapeutic targets for disorders such as Parkinson’s disease, where L-DOPA is administered to increase dopamine levels in the brain[7][2]. The action of peripheral decarboxylase inhibitors (such as carbidopa or benserazide) prevents conversion of L-DOPA outside the brain, allowing more L-DOPA to enter the central nervous system[7]. Recent research reveals that gut microbiota can also metabolize L-DOPA, impacting drug availability[4][6]. In summary, "Dopamine precursor conversion" is a process mediated primarily by **tyrosine hydroxylase** and **aromatic L-amino acid decarboxylase**, and not a receptor or single molecular target. For structured data, focus on these enzymes rather than the process name.

Other names

Tyrosine 3-monooxygenase (TH)DOPA decarboxylase (AADC)Aromatic L-amino acid decarboxylase

Substrate supplementation (e.g., L-DOPA increases dopamine synthesis); Enzyme inhibition (e.g., carbidopa inhibits AADC in the periphery, increasing L-DOPA availability in the brain); Enzyme activation (theoretical)