Component
Human tyrosinase / TYR
Context-specific entity; species, compartment and exposure are stated on each claim.
3 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What it acts on
Purified recombinant human tyrosinase showed monophenolase activity with L-tyrosine, the initial hydroxylation step toward pigment.
Experimental context and source evidence
- evidence_access
- Primary full text; Results and catalytic assays
- experimental_model
- Human intramelanosomal domain expressed in insect cells; activity assays.
- limitations
- Same metabolite identity as L-DOPA in catecholamine synthesis, but different enzyme and compartment.
- nutrient_topic
- L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
- plain_language
- A different enzyme uses the same amino acid for pigment chemistry.
- primary_references
- Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 148–154
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human intramelanosomal domain expressed in insect cells; activity assays. · source_derived_draft · unverified_draft
## l-tyrosine-tyr-dopa A different enzyme uses the same amino acid for pigment chemistry. Purified recombinant human tyrosinase showed monophenolase activity with L-tyrosine, the initial hydroxylation step toward pigment. Model: Human intramelanosomal domain expressed in insect cells; activity assays. Limitations: Same metabolite identity as L-DOPA in catecholamine synthesis, but different enzyme and compartment. Evidence access: Primary full text; Results and catalytic assays Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
Complete structured claim and evidenceRecombinant human tyrosinase also showed diphenol oxidase activity with L-DOPA, supporting the next oxidation toward dopaquinone.
Experimental context and source evidence
- evidence_access
- Primary full text; Results and catalytic assays
- experimental_model
- Purified human enzyme; L-DOPA colorimetric assays.
- limitations
- A colorimetric enzyme rate does not establish whole-body melanin output.
- nutrient_topic
- L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
- plain_language
- The pigment route includes a separate oxidation step.
- primary_references
- Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 156–162
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human enzyme; L-DOPA colorimetric assays. · source_derived_draft · unverified_draft
## l-tyrosine-tyr-quinone The pigment route includes a separate oxidation step. Recombinant human tyrosinase also showed diphenol oxidase activity with L-DOPA, supporting the next oxidation toward dopaquinone. Model: Purified human enzyme; L-DOPA colorimetric assays. Limitations: A colorimetric enzyme rate does not establish whole-body melanin output. Evidence access: Primary full text; Results and catalytic assays Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
Complete structured claim and evidenceHuman TYR R422Q and R422W variants had lower activity and temperature sensitivity compared with wild type.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_access
- Primary abstract
- experimental_model
- Purified human intramelanosomal domains expressed in insect cells.
- limitations
- These variants retain activity; they should not be conflated with all albinism variants.
- nutrient_topic
- L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
- plain_language
- Reduced pigment synthesis can reflect enzyme structure rather than low tyrosine.
- primary_references
- Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 164–170
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human intramelanosomal domains expressed in insect cells. · source_derived_draft · unverified_draft
## l-tyrosine-tyr-variants Reduced pigment synthesis can reflect enzyme structure rather than low tyrosine. Human TYR R422Q and R422W variants had lower activity and temperature sensitivity compared with wild type. Model: Purified human intramelanosomal domains expressed in insect cells. Limitations: These variants retain activity; they should not be conflated with all albinism variants. Evidence access: Primary abstract Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. · 2014 · https://pubmed.ncbi.nlm.nih.gov/24392141/ · DOI 10.1371/journal.pone.0084494
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.