Human BCO2 carotenoid cleavage activity: molecular mechanisms & dependencies

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.

Human evidence only

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.

Recorded relationships

What acts on it

The 2014 expression assay detected zeaxanthin cleavage by mouse BCO2 but not human BCO2.
Human beta-carotene oxygenase 2 / BCO2 → Human BCO2 carotenoid cleavage activity source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/lutein-research/24982131.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "975bef59c81c57ad6e18b45581b23174165732965e8d7e017275fe98ca3ab4a0", "start_char": 0, "end_char": 1743, "text_sha256": "975bef59c81c57ad6e18b45581b23174165732965e8d7e017275fe98ca3ab4a0"}
experimental_model
Recombinant enzyme expression and comparative binding
exposure
Zeaxanthin-producing bacteria; surface plasmon resonance
limitations
Historical assay result; later work demonstrates human catalytic competence with altered protein processing and expression conditions.
nutrient_topic
Lutein research collection; topical membership is not evidence of a direct dietary effect. · Lutein
organism
Human and mouse proteins; bacterial expression
plain_language
One early assay found no detectable human enzyme activity.
primary_references
[lutein-p24982131] Inactivity of human β,β-carotene-9',10'-dioxygenase (BCO2) underlies retinal accumulation of the human macular carotenoid pigment. (2014). https://pubmed.ncbi.nlm.nih.gov/24982131/ DOI: 10.1073/pnas.1402526111
tissue_or_cell_type
Recombinant BCO2 and retina
Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 255–266
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant enzyme expression and comparative binding · source_derived_draft · unverified_draft
### lutein-bco2-2014-inactive The 2014 expression assay detected zeaxanthin cleavage by mouse BCO2 but not human BCO2. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: One early assay found no detectable human enzyme activity. organism: Human and mouse proteins; bacterial expression tissue_or_cell_type: Recombinant BCO2 and retina experimental_model: Recombinant enzyme expression and comparative binding limitations: Historical assay result; later work demonstrates human catalytic competence with altered protein processing and expression conditions. exposure: Zeaxanthin-producing bacteria; surface plasmon resonance evidence_span: {"source_cache": "artifacts/lutein-research/24982131.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "975bef59c81c57ad6e18b45581b23174165732965e8d7e017275fe98ca3ab4a0", "start_char": 0, "end_char": 1743, "text_sha256": "975bef59c81c57ad6e18b45581b23174165732965e8d7e017275fe98ca3ab4a0"} [lutein-p24982131] Inactivity of human β,β-carotene-9',10'-dioxygenase (BCO2) underlies retinal accumulation of the human macular carotenoid pigment. (2014). https://pubmed.ncbi.nlm.nih.gov/24982131/ DOI: 10.1073/pnas.1402526111
Complete structured claim and evidence
Removing the mitochondrial targeting sequence improved human BCO2a solubility and enabled carotenoid-cleavage activity.
Human BCO2a with mitochondrial targeting sequence removed → Human BCO2 carotenoid cleavage activity source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/lutein-research/32873706.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1555914c4a5090c968595f2aba72ce276054594a66423916be600a600a28349f", "start_char": 0, "end_char": 1517, "text_sha256": "1555914c4a5090c968595f2aba72ce276054594a66423916be600a600a28349f"}
experimental_model
Isoform targeting, recombinant expression and enzyme assays
exposure
Removal of N-terminal mitochondrial targeting sequence; expression optimization
limitations
Activity of processed recombinant protein does not quantify retinal flux; mouse chimeric substrate results remain mouse-specific.
nutrient_topic
Lutein research collection; topical membership is not evidence of a direct dietary effect. · Lutein
organism
Human BCO2 isoforms and engineered mouse protein
plain_language
Processing and expression conditions revealed active human enzyme.
primary_references
[lutein-p32873706] The human mitochondrial enzyme BCO2 exhibits catalytic activity toward carotenoids and apocarotenoids. (2020). https://pubmed.ncbi.nlm.nih.gov/32873706/ DOI: 10.1074/jbc.ra120.015515
tissue_or_cell_type
ARPE-19 cells and bacterial expression
Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 281–292
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Isoform targeting, recombinant expression and enzyme assays · source_derived_draft · unverified_draft
### lutein-bco2-mature-active Removing the mitochondrial targeting sequence improved human BCO2a solubility and enabled carotenoid-cleavage activity. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: Processing and expression conditions revealed active human enzyme. organism: Human BCO2 isoforms and engineered mouse protein tissue_or_cell_type: ARPE-19 cells and bacterial expression experimental_model: Isoform targeting, recombinant expression and enzyme assays limitations: Activity of processed recombinant protein does not quantify retinal flux; mouse chimeric substrate results remain mouse-specific. exposure: Removal of N-terminal mitochondrial targeting sequence; expression optimization evidence_span: {"source_cache": "artifacts/lutein-research/32873706.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1555914c4a5090c968595f2aba72ce276054594a66423916be600a600a28349f", "start_char": 0, "end_char": 1517, "text_sha256": "1555914c4a5090c968595f2aba72ce276054594a66423916be600a600a28349f"} [lutein-p32873706] The human mitochondrial enzyme BCO2 exhibits catalytic activity toward carotenoids and apocarotenoids. (2020). https://pubmed.ncbi.nlm.nih.gov/32873706/ DOI: 10.1074/jbc.ra120.015515
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.

Human BCO2 carotenoid cleavage activity