Protein / target

Aromatic-L-amino-acid decarboxylase

DDCP20711Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

5-hydroxy-L-tryptophan decarboxylase activity

Strongest disease association

aromatic L-amino acid decarboxylase deficiency

Genetic evidence · score 0.92

Therapeutic maturity

Clinically validated target

2 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

2 approved · 2 in clinical development

30 linked trials

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function

Catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (DOPA) to dopamine and L-5-hydroxytryptophan to serotonin

Domains and Gene Ontology detail (13)

Gene Ontology

  • Ccytoplasm
  • Ccytosol
  • Cextracellular exosome
  • F5-hydroxy-L-tryptophan decarboxylase activity
  • Faromatic-L-amino-acid decarboxylase activity
  • Fenzyme binding
  • FL-dopa decarboxylase activity
  • Fpyridoxal phosphate binding
  • Pamino acid metabolic process
  • Pcarboxylic acid metabolic process
  • Pcatecholamine metabolic process
  • Pdopamine biosynthetic process

480 aa · 54 kDa · 4 isoforms

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

Metabolic enzyme activityGO
View supporting evidence

Metabolic enzyme activity

  • ·amino acid metabolic process
  • ·carboxylic acid metabolic process
  • ·catecholamine metabolic process
View underlying pathways (2)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

THMAOBMAOADBHPAHCOMTTPH1LRTOMTTPH2AOC1DDC

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

Carbidopa
Narrow target profileApprovedInhibitor

DOPA decarboxylase inhibitor

Appears in clinical studies involving Parkinson disease, Parkinson disease, injury, secondary Parkinson disease

Direct interaction with this protein · Only this protein recorded as a target

ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

aromatic L-amino acid decarboxylase deficiency0.92

Genetic · overall 0.84

Abnormality of the skeletal system0.83

Genetic · overall 0.50

hereditary disease0.83

Genetic · overall 0.51

Global developmental delay0.61

Genetic literature · overall 0.40

Dystonia0.61

Genetic literature · overall 0.37

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

Parkinson disease0.99

Clinical · overall 0.62

injury0.83

Clinical · overall 0.50

inborn disorder of amino acid metabolism0.76

Clinical · overall 0.46

postencephalitic Parkinson disease0.61

Clinical · overall 0.38

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

oculogyric crisis0.37

Genetic literature

Show all associations
aromatic L-amino acid decarboxylase deficiency0.84
Parkinson disease0.62
hereditary disease0.51
Abnormality of the skeletal system0.50
injury0.50
inborn disorder of amino acid metabolism0.46
Global developmental delay0.40
postencephalitic Parkinson disease0.38
Dystonia0.37
oculogyric crisis0.37

Open Targets ranks 1,155 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 4 total

CARBIDOPAApproval

Parkinson disease · Parkinson disease · injury

ELADOCAGENE EXUPARVOVECApproval

inborn disorder of amino acid metabolism · aromatic L-amino acid decarboxylase deficiency · Parkinson disease

FOSCARBIDOPAPhase 3

Parkinson disease · Parkinson disease

BENSERAZIDEPhase 3

restless legs syndrome · Parkinson disease · Parkinson disease

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality PocketSM · Druggable Family

Safety liabilities

addiction

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.

Show remaining trials (24)

RECRUITING · via Carbidopa · NCT05285683

COMPLETED · via Carbidopa · NCT03929068

COMPLETED · via Carbidopa · NCT06587217

COMPLETED · via Carbidopa · NCT06219915

ClinicalTrials.gov via the drug-target graph.

Related literature

1

Papers indexed under “Dopa Decarboxylase” — a subject heading that covers this protein without being specific to it. Shown as context; not counted as this protein's own research activity.

Europe PMC literature, reached through a MeSH descriptor linked to this protein.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

aromatic L-amino acid decarboxylase deficiencyWell supported
0.94
agreement 0.841.00
Genetic79%Animal model10%Clinical10%Literature1%Genetic literaturedup

Open Targets aggregate 0.84 · 4 independent evidence families · 1 not counted as duplicate

hereditary diseaseWell supported
0.83
agreement 0.690.97
Genetic98%Literature2%

Open Targets aggregate 0.51 · 2 independent evidence families

Abnormality of the skeletal systemWell supported
0.83
agreement 0.710.95
Genetic100%

Open Targets aggregate 0.50 · 1 independent evidence family

Parkinson diseaseWell supported
0.79
agreement 0.680.91
Clinical80%Animal model12%Literature7%RNA expression1%

Open Targets aggregate 0.62 · 4 independent evidence families

injuryModerately supported
0.62
agreement 0.460.79
Clinical100%

Open Targets aggregate 0.50 · 1 independent evidence family

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the underlying per-type scores are shown above so the calculation can be checked.

What's happening now

4

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. Label change2026-05-15

    Label change: CARBIDOPA AND LEVODOPA (NDA217186)

    fda · regulatory · fda · via Carbidopa

  2. Label change2026-03-19

    Label change: CARBIDOPA AND LEVODOPA (NDA217186)

    fda · regulatory · fda · via Carbidopa

  3. Regulatory approval2024-08-07

    Approval: CARBIDOPA AND LEVODOPA (NDA217186)

    fda · regulatory · fda · via Carbidopa

  4. New publication2004-12-01
    Levodopa and the progression of Parkinson's disease.

    The New England journal of medicine · 2004 · 1,175 citations · Europe PMC · via Carbidopa

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.