Component
Protoporphyrin IX
Iron-free porphyrin control in the TPO expression study.
2 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 acts on it
Human ferrochelatase inserts ferrous iron into protoporphyrin to form heme.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/iron-research/11175906.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ba1c88d4630f6f0ee7f70989705c81162a2f8651c066f46b3aac73988b8dfa11", "start_char": 0, "end_char": 770, "text_sha256": "ba1c88d4630f6f0ee7f70989705c81162a2f8651c066f46b3aac73988b8dfa11"}
- experimental_model
- Human ferrochelatase crystal structure
- exposure
- 2.0 angstrom structure and biochemical catalytic interpretation
- limitations
- Purified enzyme; cluster structure is not a human dietary-iron threshold.
- nutrient_topic
- Iron research collection; topical membership is not evidence of a direct dietary effect. · Iron
- organism
- Human enzyme
- plain_language
- The last step places an iron atom inside the finished heme ring.
- primary_references
- [iron-p11175906] The 2.0 A structure of human ferrochelatase, the terminal enzyme of heme biosynthesis. (2001). https://pubmed.ncbi.nlm.nih.gov/11175906/ DOI: 10.1038/84152
- tissue_or_cell_type
- Mitochondrial membrane-associated enzyme
Iron: absorption, trafficking, iron-dependent enzymes and nutrient interactions (2026-09-17) · lines 511–522
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human ferrochelatase crystal structure · source_derived_draft · unverified_draft
### iron-fech-heme Human ferrochelatase inserts ferrous iron into protoporphyrin to form heme. Condition category: normal nutrient_topic: Iron research collection; topical membership is not evidence of a direct dietary effect. plain_language: The last step places an iron atom inside the finished heme ring. organism: Human enzyme tissue_or_cell_type: Mitochondrial membrane-associated enzyme experimental_model: Human ferrochelatase crystal structure limitations: Purified enzyme; cluster structure is not a human dietary-iron threshold. exposure: 2.0 angstrom structure and biochemical catalytic interpretation evidence_span: {"source_cache": "artifacts/iron-research/11175906.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ba1c88d4630f6f0ee7f70989705c81162a2f8651c066f46b3aac73988b8dfa11", "start_char": 0, "end_char": 770, "text_sha256": "ba1c88d4630f6f0ee7f70989705c81162a2f8651c066f46b3aac73988b8dfa11"} [iron-p11175906] The 2.0 A structure of human ferrochelatase, the terminal enzyme of heme biosynthesis. (2001). https://pubmed.ncbi.nlm.nih.gov/11175906/ DOI: 10.1038/84152
Complete structured claim and evidence
Where it participates (unsigned role)
Adding hemin or hematin to CHO expression cultures increased heme incorporation and guaiacol activity of purified human TPO ectodomain relative to the iron-free porphyrin comparison.
Experimental context and source evidence
- cross_nutrient
- true
- evidence_span
- {"source_cache": "artifacts/iodine-synthesis-sources/9492031.json", "json_field": "abstractText", "text_sha256": "4a73f43b4e982a85a7e632cc57a8db51a590eb23fa1d578a448cab52b2d8405f", "text_characters": 2006, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}
- experimental_model
- Recombinant human TPO ectodomain residues 1–848 expressed in Chinese hamster ovary cells
- exposure
- 1 mg/L hemin, hematin or protoporphyrin IX in expression cultures; human ectodomain 1–848.
- limitations
- Guaiacol assay and recombinant construct; not a human dietary iron-repletion experiment.
- nutrient_topic
- Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
- organism
- Homo sapiens protein; Cricetulus griseus host cells
- plain_language
- Iron-containing heme helps TPO become an active enzyme.
- primary_references
- [iodine-syn-tpo1998] The greater glycan content of recombinant human thyroid peroxidase of mammalian than of insect cell origin facilitates purification to homogeneity of enzymatically protein remaining soluble at high concentration. (1998). https://pubmed.ncbi.nlm.nih.gov/9492031/ DOI: 10.1210/endo.139.3.5782
- tissue_or_cell_type
- CHO expression system; purified protein
Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 562–574
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human TPO ectodomain residues 1–848 expressed in Chinese hamster ovary cells · source_derived_draft · unverified_draft
### iodine-syn-heme-activity Adding hemin or hematin to CHO expression cultures increased heme incorporation and guaiacol activity of purified human TPO ectodomain relative to the iron-free porphyrin comparison. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Iron-containing heme helps TPO become an active enzyme. organism: Homo sapiens protein; Cricetulus griseus host cells tissue_or_cell_type: CHO expression system; purified protein experimental_model: Recombinant human TPO ectodomain residues 1–848 expressed in Chinese hamster ovary cells limitations: Guaiacol assay and recombinant construct; not a human dietary iron-repletion experiment. exposure: 1 mg/L hemin, hematin or protoporphyrin IX in expression cultures; human ectodomain 1–848. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/9492031.json", "json_field": "abstractText", "text_sha256": "4a73f43b4e982a85a7e632cc57a8db51a590eb23fa1d578a448cab52b2d8405f", "text_characters": 2006, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-tpo1998] The greater glycan content of recombinant human thyroid peroxidase of mammalian than of insect cell origin facilitates purification to homogeneity of enzymatically protein remaining soluble at high concentration. (1998). https://pubmed.ncbi.nlm.nih.gov/9492031/ DOI: 10.1210/endo.139.3.5782
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.