Human iodotyrosine deiodinase

Where it participates (unsigned role)

1. Replacing FMN with 2-prime-deoxyFMN in human IYD lowered iodotyrosine dehalogenation efficiency by more than fivefold while increasing turnover number by more than sixfold.

   2-prime-Deoxy-FMN → Iyd catalytic efficiency source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   true

   evidence_span

   {"source_cache": "artifacts/iodine-synthesis-sources/37654510.txt", "start_char": 9069, "end_char": 10489, "text_sha256": "5e0dc84da55832b58d1a1ad6c3a327551b878ef108389abf34b7eda4dcc8b7a1", "text_characters": 1420, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}

   experimental_model

   Purified soluble human IYD reconstituted with FMN or synthetic 2-prime-deoxyFMN

   exposure

   Human IYD reconstituted with FMN or synthetic 2-prime-deoxyFMN; Table 1 kcat/Km 5.0 versus 0.97 x 10^3 M^-1 s^-1; kcat 0.052 versus 0.32 s^-1.

   limitations

   Synthetic cofactor substitution is not riboflavin deficiency; kcat/Km and kcat are different measurements. Table 1 native-FMN kinetic comparator is cited from previous work; reconstituted FMN was used for binding comparisons.

   nutrient_topic

   Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine

   organism

   Homo sapiens recombinant protein

   plain_language

   A small change to FMN weakened overall substrate processing even though the saturated enzyme turned over faster.

   primary_references

   [iodine-syn-iyd2023] The 2'-hydroxy group of flavin mononucleotide influences the catalytic function and promiscuity of the flavoprotein iodotyrosine dehalogenase. (2023). https://pubmed.ncbi.nlm.nih.gov/37654510/ DOI: 10.1039/d3cb00094j

   tissue_or_cell_type

   Purified enzyme

   Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 730–742

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified soluble human IYD reconstituted with FMN or synthetic 2-prime-deoxyFMN · source_derived_draft · unverified_draft

   ### iodine-syn-iyd-cofactor-substitution Replacing FMN with 2-prime-deoxyFMN in human IYD lowered iodotyrosine dehalogenation efficiency by more than fivefold while increasing turnover number by more than sixfold. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: A small change to FMN weakened overall substrate processing even though the saturated enzyme turned over faster. organism: Homo sapiens recombinant protein tissue_or_cell_type: Purified enzyme experimental_model: Purified soluble human IYD reconstituted with FMN or synthetic 2-prime-deoxyFMN limitations: Synthetic cofactor substitution is not riboflavin deficiency; kcat/Km and kcat are different measurements. Table 1 native-FMN kinetic comparator is cited from previous work; reconstituted FMN was used for binding comparisons. exposure: Human IYD reconstituted with FMN or synthetic 2-prime-deoxyFMN; Table 1 kcat/Km 5.0 versus 0.97 x 10^3 M^-1 s^-1; kcat 0.052 versus 0.32 s^-1. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/37654510.txt", "start_char": 9069, "end_char": 10489, "text_sha256": "5e0dc84da55832b58d1a1ad6c3a327551b878ef108389abf34b7eda4dcc8b7a1", "text_characters": 1420, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-iyd2023] The 2'-hydroxy group of flavin mononucleotide influences the catalytic function and promiscuity of the flavoprotein iodotyrosine dehalogenase. (2023). https://pubmed.ncbi.nlm.nih.gov/37654510/ DOI: 10.1039/d3cb00094j

   Complete structured claim and evidence

2. Purified soluble human IYD released radiolabeled iodide from diiodotyrosine during reductive enzyme assays.

   Human IYD lacking N-terminal membrane anchor → Iodide ion source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   true

   evidence_span

   {"source_cache": "artifacts/iodine-synthesis-sources/25395621.txt", "start_char": 11103, "end_char": 12723, "text_sha256": "726c34262182d49a45a4741a29a49ef70bf6d529c79d75cfbb0e9ea59ffd256b", "text_characters": 1620, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}

   experimental_model

   Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration

   exposure

   0–70 micromolar [125I]DIT; sodium dithionite supplies reducing equivalents.

   limitations

   Anchor-deleted enzyme and artificial reductant; does not identify the physiological electron donor.

   nutrient_topic

   Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine

   organism

   Homo sapiens recombinant protein

   plain_language

   IYD recovers iodine from leftover iodinated tyrosine.

   primary_references

   [iodine-syn-iyd2015] A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate. (2015). https://pubmed.ncbi.nlm.nih.gov/25395621/ DOI: 10.1074/jbc.m114.605964

   tissue_or_cell_type

   Purified soluble IYD

   Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 688–700

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration · source_derived_draft · unverified_draft

   ### iodine-syn-iyd-dit-salvage Purified soluble human IYD released radiolabeled iodide from diiodotyrosine during reductive enzyme assays. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: IYD recovers iodine from leftover iodinated tyrosine. organism: Homo sapiens recombinant protein tissue_or_cell_type: Purified soluble IYD experimental_model: Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration limitations: Anchor-deleted enzyme and artificial reductant; does not identify the physiological electron donor. exposure: 0–70 micromolar [125I]DIT; sodium dithionite supplies reducing equivalents. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/25395621.txt", "start_char": 11103, "end_char": 12723, "text_sha256": "726c34262182d49a45a4741a29a49ef70bf6d529c79d75cfbb0e9ea59ffd256b", "text_characters": 1620, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-iyd2015] A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate. (2015). https://pubmed.ncbi.nlm.nih.gov/25395621/ DOI: 10.1074/jbc.m114.605964

   Complete structured claim and evidence

3. Human IYD crystal structures show one bound FMN per polypeptide, with iodotyrosine contacting its isoalloxazine ring in the substrate complex.

   Human IYD lacking N-terminal membrane anchor → Flavin mononucleotide source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   true

   evidence_span

   {"source_cache": "artifacts/iodine-synthesis-sources/25395621.txt", "start_char": 14596, "end_char": 15366, "text_sha256": "5f3959109e358adaddae3ea78c716d16316c28f6fb4153ad5696bae7b1ed733e", "text_characters": 770, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}

   experimental_model

   Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration

   exposure

   Human soluble IYD crystallized alone or with 3-iodo-L-tyrosine.

   limitations

   Cofactor structure; no riboflavin restriction or supplementation study.

   nutrient_topic

   Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine

   organism

   Homo sapiens recombinant protein

   plain_language

   IYD uses the vitamin-B2-derived cofactor FMN to handle iodotyrosine.

   primary_references

   [iodine-syn-iyd2015] A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate. (2015). https://pubmed.ncbi.nlm.nih.gov/25395621/ DOI: 10.1074/jbc.m114.605964

   tissue_or_cell_type

   Purified soluble IYD

   Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 702–714

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration · source_derived_draft · unverified_draft

   ### iodine-syn-iyd-fmn-binding Human IYD crystal structures show one bound FMN per polypeptide, with iodotyrosine contacting its isoalloxazine ring in the substrate complex. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: IYD uses the vitamin-B2-derived cofactor FMN to handle iodotyrosine. organism: Homo sapiens recombinant protein tissue_or_cell_type: Purified soluble IYD experimental_model: Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration limitations: Cofactor structure; no riboflavin restriction or supplementation study. exposure: Human soluble IYD crystallized alone or with 3-iodo-L-tyrosine. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/25395621.txt", "start_char": 14596, "end_char": 15366, "text_sha256": "5f3959109e358adaddae3ea78c716d16316c28f6fb4153ad5696bae7b1ed733e", "text_characters": 770, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-iyd2015] A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate. (2015). https://pubmed.ncbi.nlm.nih.gov/25395621/ DOI: 10.1074/jbc.m114.605964

   Complete structured claim and evidence

4. The IYD variants identified in four affected patients showed markedly reduced iodotyrosine-deiodinase activity in vitro.

   Human IYD patient variant proteins studied in 2008 → Iodotyrosine deiodination source_derived_draftungraded
   Experimental context and source evidence

   availability_state

   machinery_impairment Imported condition classification; unverified.

   cross_nutrient

   true

   evidence_span

   {"source_cache": "artifacts/iodine-synthesis-sources/18434651.json", "json_field": "abstractText", "text_sha256": "f257956854445e268691cd3df1388ca16cea3f41320a48753df200a381c56431", "text_characters": 914, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}

   experimental_model

   Four selected patients from three unrelated families plus in-vitro mutant enzyme assays

   exposure

   Two missense variants and one three-base-pair deletion; no nutrient-restriction experiment.

   limitations

   Abstract does not provide exact variant residues or assay dose.

   nutrient_topic

   Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine

   organism

   Homo sapiens proteins

   plain_language

   Genetic defects can disable iodine recycling.

   primary_references

   [iodine-syn-iyd2008] Mutations in the iodotyrosine deiodinase gene and hypothyroidism. (2008). https://pubmed.ncbi.nlm.nih.gov/18434651/ DOI: 10.1056/nejmoa0706819

   tissue_or_cell_type

   In-vitro enzyme assays

   trigger_kind

   machinery_impairment Imported condition classification; unverified.

   Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 744–756

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Four selected patients from three unrelated families plus in-vitro mutant enzyme assays · source_derived_draft · unverified_draft

   ### iodine-syn-iyd-mutant-activity The IYD variants identified in four affected patients showed markedly reduced iodotyrosine-deiodinase activity in vitro. Condition category: machinery_impairment nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Genetic defects can disable iodine recycling. organism: Homo sapiens proteins tissue_or_cell_type: In-vitro enzyme assays experimental_model: Four selected patients from three unrelated families plus in-vitro mutant enzyme assays limitations: Abstract does not provide exact variant residues or assay dose. exposure: Two missense variants and one three-base-pair deletion; no nutrient-restriction experiment. cross_nutrient: true evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/18434651.json", "json_field": "abstractText", "text_sha256": "f257956854445e268691cd3df1388ca16cea3f41320a48753df200a381c56431", "text_characters": 914, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-iyd2008] Mutations in the iodotyrosine deiodinase gene and hypothyroidism. (2008). https://pubmed.ncbi.nlm.nih.gov/18434651/ DOI: 10.1056/nejmoa0706819

   Complete structured claim and evidence

5. The four patients with damaging IYD variants developed severe goitrous hypothyroidism evident in infancy or childhood.

   Human IYD patient variant proteins studied in 2008 → Goitrous hypothyroidism source_derived_draftungraded
   Experimental context and source evidence

   availability_state

   machinery_impairment Imported condition classification; unverified.

   cross_nutrient

   false

   evidence_span

   {"source_cache": "artifacts/iodine-synthesis-sources/18434651.json", "json_field": "abstractText", "text_sha256": "f257956854445e268691cd3df1388ca16cea3f41320a48753df200a381c56431", "text_characters": 914, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."}

   experimental_model

   Four selected patients from three unrelated families plus in-vitro mutant enzyme assays

   exposure

   Inherited enzyme variants in three unrelated families.

   limitations

   Selected cases; does not establish dietary deficiency or population prevalence.

   nutrient_topic

   Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine

   organism

   Homo sapiens

   plain_language

   Failure to recycle iodine can impair hormone production after birth.

   primary_references

   [iodine-syn-iyd2008] Mutations in the iodotyrosine deiodinase gene and hypothyroidism. (2008). https://pubmed.ncbi.nlm.nih.gov/18434651/ DOI: 10.1056/nejmoa0706819

   tissue_or_cell_type

   Thyroid and systemic thyroid function

   trigger_kind

   machinery_impairment Imported condition classification; unverified.

   Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 758–770

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Four selected patients from three unrelated families plus in-vitro mutant enzyme assays · source_derived_draft · unverified_draft

   ### iodine-syn-iyd-mutant-phenotype The four patients with damaging IYD variants developed severe goitrous hypothyroidism evident in infancy or childhood. Condition category: machinery_impairment nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Failure to recycle iodine can impair hormone production after birth. organism: Homo sapiens tissue_or_cell_type: Thyroid and systemic thyroid function experimental_model: Four selected patients from three unrelated families plus in-vitro mutant enzyme assays limitations: Selected cases; does not establish dietary deficiency or population prevalence. exposure: Inherited enzyme variants in three unrelated families. cross_nutrient: false evidence_span: {"source_cache": "artifacts/iodine-synthesis-sources/18434651.json", "json_field": "abstractText", "text_sha256": "f257956854445e268691cd3df1388ca16cea3f41320a48753df200a381c56431", "text_characters": 914, "note": "Exact publisher passage retained in the cited local source cache; locator and digest supplied here."} [iodine-syn-iyd2008] Mutations in the iodotyrosine deiodinase gene and hypothyroidism. (2008). https://pubmed.ncbi.nlm.nih.gov/18434651/ DOI: 10.1056/nejmoa0706819

   Complete structured claim and evidence