Tyrosine

Category: amino-acid

Aliases: Tyr, Y, L-Tyrosine

Pharmacological Mechanism

Catecholamine pathway: Tyr → L-DOPA (tyrosine hydroxylase, rate-limiting; see catecholamine synthesis) → dopamine (AADC) → norepinephrine (DβH) → epinephrine (PNMT). Also substrate for thyroid hormone (T3/T4 is iodinated tyrosine) and melanin (via tyrosinase). Phosphorylation site (tyrosine kinase family).

Half-Life (t½)

PO: 1.5h

Dosing Guidelines

• PO: Typical 2 g (Range: 2–2 g)

Target Organ Systems

• endocrine
• integumentary

Interactions

• Levodopa (synergistic): Downstream of tyrosine via tyrosine hydroxylase (rate-limiting). L-DOPA bypasses the TH step.
• Dopamine (synergistic): Dietary precursor via tyrosine hydroxylase (rate-limiting).

Pathways It Modulates

• Tyrosine metabolism (broader) (substrate) — Tyr → DOPA → catecholamines

Chemical Identifiers

• PubChem CID: 6057
• Formula: C9H11NO3
• Molecular weight: 181.19 g/mol
• InChIKey: OUYCCCASQSFEME-QMMMGPOBSA-N
• SMILES: C1=CC(=CC=C1C[C@@H](C(=O)O)N)O

References

• PMID 10837313
• PMID 29168741