Component

Thyroglobulin-bound diiodotyrosyl residues

Di-iodinated tyrosyl side chains covalently incorporated into TG; distinct from free 3,5-diiodo-L-tyrosine released by proteolysis.

5 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

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.

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

Where it participates (unsigned role)

  1. Human thyroglobulin cryo-EM and site-directed mutagenesis identified tyrosine donor-acceptor pairs supporting hormone formation in vitro.

    Human thyroglobulin → Human thyroglobulin hormonogenic tyrosine pairs source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human TG expressed in HEK293T cells; cryo-EM and in vitro hormone assays.
    limitations
    This does not mean free tyrosine is directly iodinated into circulating thyroid hormone.
    nutrient_topic
    L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
    plain_language
    The thyroid uses selected tyrosines already built into a protein.
    primary_references
    The structure of human thyroglobulin. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32025030/ · DOI 10.1038/s41586-020-1995-4

    L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 132–138

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human TG expressed in HEK293T cells; cryo-EM and in vitro hormone assays. · source_derived_draft · unverified_draft

    ## l-tyrosine-tg-iodinated-pairs The thyroid uses selected tyrosines already built into a protein. Human thyroglobulin cryo-EM and site-directed mutagenesis identified tyrosine donor-acceptor pairs supporting hormone formation in vitro. Model: Human TG expressed in HEK293T cells; cryo-EM and in vitro hormone assays. Limitations: This does not mean free tyrosine is directly iodinated into circulating thyroid hormone. Evidence access: Primary abstract The structure of human thyroglobulin. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32025030/ · DOI 10.1038/s41586-020-1995-4
    Complete structured claim and evidence

  2. During TPO-catalyzed hormone formation in TG, approximately one protein-bound dehydroalanine residue was formed per hormone residue.

    Porcine thyroid peroxidase → Thyroglobulin-bound dehydroalanyl residues source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_span
    {"source_cache": "artifacts/iodine-synthesis-sources/7372636.txt", "start_char": 1081, "end_char": 2101, "text_sha256": "5ea5287db6f28391150ad5b783a0be5e450fd71f22b92028fefb7900c686c636", "text_characters": 1020, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}
    experimental_model
    Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses
    exposure
    Hog TPO with human goiter TG and radiolabeled hog TG; dehydroalanine quantified after benzyl-mercaptan addition or borohydride reduction and hydrolysis.
    limitations
    Chemical trapping identifies the retained donor remnant; it does not prove every proposed radical intermediate or identify individual T3 donor sites.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Sus scrofa enzyme; Homo sapiens and Sus scrofa TG in separate experiments
    plain_language
    Coupling leaves a dehydroalanine remnant on the donor side of TG while creating a hormone residue.
    primary_references
    [iodine-syn-tpo-coupling1980] Formation of dehydroalanine residues during thyroid hormone synthesis in thyroglobulin. (1980). https://pubmed.ncbi.nlm.nih.gov/7372636/ DOI: 10.1016/S0021-9258(19)70782-0
    tissue_or_cell_type
    Purified-protein reactions

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 870–882

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses · source_derived_draft · unverified_draft

    ### iodine-syn-coupling-dehydroalanine During TPO-catalyzed hormone formation in TG, approximately one protein-bound dehydroalanine residue was formed per hormone residue. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Coupling leaves a dehydroalanine remnant on the donor side of TG while creating a hormone residue. organism: Sus scrofa enzyme; Homo sapiens and Sus scrofa TG in separate experiments tissue_or_cell_type: Purified-protein reactions experimental_model: Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses limitations: Chemical trapping identifies the retained donor remnant; it does not prove every proposed radical intermediate or identify individual T3 donor sites. exposure: Hog TPO with human goiter TG and radiolabeled hog TG; dehydroalanine quantified after benzyl-mercaptan addition or borohydride reduction and hydrolysis. cross_nutrient: false evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/7372636.txt", "start_char": 1081, "end_char": 2101, "text_sha256": "5ea5287db6f28391150ad5b783a0be5e450fd71f22b92028fefb7900c686c636", "text_characters": 1020, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-tpo-coupling1980] Formation of dehydroalanine residues during thyroid hormone synthesis in thyroglobulin. (1980). https://pubmed.ncbi.nlm.nih.gov/7372636/ DOI: 10.1016/S0021-9258(19)70782-0
    Complete structured claim and evidence

  3. Recombinant human TPO catalyzed T4 formation from recombinant human TG in the direct TPO-versus-lactoperoxidase comparison.

    Human TPO ectodomain residues 1–838 → Human thyroglobulin containing covalent T4 residues source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    evidence_span
    {"source_cache": "artifacts/iodine-synthesis-sources/32025030.txt", "start_char": 37661, "end_char": 38631, "text_sha256": "edbab2cbd62ebd263ef59f543f10aad3692d3a3983ef5abad904e697ea34ca04", "text_characters": 970, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}
    experimental_model
    Human TG cryo-EM, recombinant HEK293T-expressed TG and site-directed mutants
    exposure
    Extended Data Fig.6c: 0.1 micromolar TG, 1 mM KI, glucose/glucose oxidase peroxide supply, 10 minutes at 37 C; TPO added at fivefold the LPO concentration to compensate for approximately 20% heme occupancy; T4 measured after Pronase digestion.
    limitations
    This identifies the TPO-containing assay arm; most TG mutagenesis experiments used LPO. The measured T4 was liberated by assay proteolysis after formation on TG.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Homo sapiens TG and TPO; HEK293T TG expression and insect-cell TPO expression
    plain_language
    Human TPO can drive hormone formation on human thyroglobulin.
    primary_references
    [iodine-syn-tg2020] The structure of human thyroglobulin. (2020). https://pubmed.ncbi.nlm.nih.gov/32025030/ DOI: 10.1038/s41586-020-1995-4
    tissue_or_cell_type
    Purified-protein reconstitution

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 842–854

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human TG cryo-EM, recombinant HEK293T-expressed TG and site-directed mutants · source_derived_draft · unverified_draft

    ### iodine-syn-human-tpo-t4-synthesis Recombinant human TPO catalyzed T4 formation from recombinant human TG in the direct TPO-versus-lactoperoxidase comparison. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Human TPO can drive hormone formation on human thyroglobulin. organism: Homo sapiens TG and TPO; HEK293T TG expression and insect-cell TPO expression tissue_or_cell_type: Purified-protein reconstitution experimental_model: Human TG cryo-EM, recombinant HEK293T-expressed TG and site-directed mutants limitations: This identifies the TPO-containing assay arm; most TG mutagenesis experiments used LPO. The measured T4 was liberated by assay proteolysis after formation on TG. exposure: Extended Data Fig.6c: 0.1 micromolar TG, 1 mM KI, glucose/glucose oxidase peroxide supply, 10 minutes at 37 C; TPO added at fivefold the LPO concentration to compensate for approximately 20% heme occupancy; T4 measured after Pronase digestion. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/32025030.txt", "start_char": 37661, "end_char": 38631, "text_sha256": "edbab2cbd62ebd263ef59f543f10aad3692d3a3983ef5abad904e697ea34ca04", "text_characters": 970, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-tg2020] The structure of human thyroglobulin. (2020). https://pubmed.ncbi.nlm.nih.gov/32025030/ DOI: 10.1038/s41586-020-1995-4
    Complete structured claim and evidence

  4. Purified hog TPO catalyzed iodine incorporation into hog thyroglobulin in kinetic assays of protein iodination.

    Porcine thyroid peroxidase → Porcine thyroglobulin iodination source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_span
    {"source_cache": "artifacts/iodine-synthesis-sources/6706940.json", "json_field": "abstractText", "text_sha256": "e7d184d64b66b0dc89f61c511688c79ffc9785b20233e7746ef4c97de351c78c", "text_characters": 1442, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}
    experimental_model
    Purified hog thyroid peroxidase with hog thyroglobulin; steady-state and stopped-flow kinetics
    exposure
    Purified hog TPO; native TG with 1.0% iodine and further-iodinated TG with 1.2% iodine; reagent concentrations not stated in abstract.
    limitations
    Reaction measures TG iodination, not free iodotyrosine recycling. The proposed iodinium intermediate is a model, not imported as an established mechanism.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Sus scrofa
    plain_language
    TPO attaches iodine to tyrosine residues within the TG protein.
    primary_references
    [iodine-syn-tpo-iodination1984] Iodination and oxidation of thyroglobulin catalyzed by thyroid peroxidase. (1984). https://pubmed.ncbi.nlm.nih.gov/6706940/ DOI: 10.1016/s0021-9258(17)43667-2
    tissue_or_cell_type
    Purified thyroid enzyme and protein substrate

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 828–840

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified hog thyroid peroxidase with hog thyroglobulin; steady-state and stopped-flow kinetics · source_derived_draft · unverified_draft

    ### iodine-syn-tpo-protein-iodination Purified hog TPO catalyzed iodine incorporation into hog thyroglobulin in kinetic assays of protein iodination. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: TPO attaches iodine to tyrosine residues within the TG protein. organism: Sus scrofa tissue_or_cell_type: Purified thyroid enzyme and protein substrate experimental_model: Purified hog thyroid peroxidase with hog thyroglobulin; steady-state and stopped-flow kinetics limitations: Reaction measures TG iodination, not free iodotyrosine recycling. The proposed iodinium intermediate is a model, not imported as an established mechanism. exposure: Purified hog TPO; native TG with 1.0% iodine and further-iodinated TG with 1.2% iodine; reagent concentrations not stated in abstract. cross_nutrient: false evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/6706940.json", "json_field": "abstractText", "text_sha256": "e7d184d64b66b0dc89f61c511688c79ffc9785b20233e7746ef4c97de351c78c", "text_characters": 1442, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-tpo-iodination1984] Iodination and oxidation of thyroglobulin catalyzed by thyroid peroxidase. (1984). https://pubmed.ncbi.nlm.nih.gov/6706940/ DOI: 10.1016/s0021-9258(17)43667-2
    Complete structured claim and evidence

  5. Iodinating human goiter TG with hog TPO for 90 minutes produced 0.3 T3 residues per TG molecule, measured after enzymatic hydrolysis.

    Porcine thyroid peroxidase → Human thyroglobulin containing covalent T3 residues source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_span
    {"source_cache": "artifacts/iodine-synthesis-sources/7372636.txt", "start_char": 6216, "end_char": 8536, "text_sha256": "753e684061b9063528196c840b23404015abc2b7b836a3887497aea0f8fe20a6", "text_characters": 2320, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}
    experimental_model
    Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses
    exposure
    Human goiter TG initially 0.04% iodine, iodinated for 90 minutes to approximately 60 iodine atoms per TG; the same preparation contained 2.6 T4 residues per molecule.
    limitations
    Reconstituted mixed-species experiment. Hormone residues are protein-bound before hydrolysis; the assay is not evidence that free MIT and DIT are routinely coupled in blood.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Sus scrofa enzyme; Homo sapiens substrate
    plain_language
    TPO-driven chemistry can make T3 directly within TG, before the hormone is released.
    primary_references
    [iodine-syn-tpo-coupling1980] Formation of dehydroalanine residues during thyroid hormone synthesis in thyroglobulin. (1980). https://pubmed.ncbi.nlm.nih.gov/7372636/ DOI: 10.1016/S0021-9258(19)70782-0
    tissue_or_cell_type
    Purified TPO and human goiter TG

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 856–868

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses · source_derived_draft · unverified_draft

    ### iodine-syn-tpo-t3-formation Iodinating human goiter TG with hog TPO for 90 minutes produced 0.3 T3 residues per TG molecule, measured after enzymatic hydrolysis. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: TPO-driven chemistry can make T3 directly within TG, before the hormone is released. organism: Sus scrofa enzyme; Homo sapiens substrate tissue_or_cell_type: Purified TPO and human goiter TG experimental_model: Purified hog TPO with human goiter TG or tyrosine-radiolabeled hog TG; chromatographic hormone and dehydroalanine analyses limitations: Reconstituted mixed-species experiment. Hormone residues are protein-bound before hydrolysis; the assay is not evidence that free MIT and DIT are routinely coupled in blood. exposure: Human goiter TG initially 0.04% iodine, iodinated for 90 minutes to approximately 60 iodine atoms per TG; the same preparation contained 2.6 T4 residues per molecule. cross_nutrient: false evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/7372636.txt", "start_char": 6216, "end_char": 8536, "text_sha256": "753e684061b9063528196c840b23404015abc2b7b836a3887497aea0f8fe20a6", "text_characters": 2320, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-tpo-coupling1980] Formation of dehydroalanine residues during thyroid hormone synthesis in thyroglobulin. (1980). https://pubmed.ncbi.nlm.nih.gov/7372636/ DOI: 10.1016/S0021-9258(19)70782-0
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

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