{"id":"fa350778-d209-5eb8-9a2e-e5ce51a00864","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-th-iron","predicate":"is_active_site_metal_of","statement":"Reconstituted human TH1 contained high-spin Fe(II); dehydration changed iron coordination and rehydration reversed the spectroscopic change.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"40c34c1a-a95f-553d-b31e-53dc557a6790","mechanism_event_label":"Iron participates in the enzyme itself, and its local environment matters.","subject":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"object":{"id":"e4e0f24b-1e70-573d-b719-039a90191b90","slug":"human-tyrosine-hydroxylase","display_name":"Human tyrosine hydroxylase","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"40c34c1a-a95f-553d-b31e-53dc557a6790","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-th-iron-event","event_type":"observed_relationship","label":"Iron participates in the enzyme itself, and its local environment matters.","description":"Reconstituted human TH1 contained high-spin Fe(II); dehydration changed iron coordination and rehydration reversed the spectroscopic change.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e4e0f24b-1e70-573d-b719-039a90191b90","slug":"human-tyrosine-hydroxylase","display_name":"Human tyrosine hydroxylase","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified full-length and truncated human TH1; Mossbauer and X-ray absorption spectroscopy.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"A hydration-dependent structural change is not evidence that ordinary dehydration causes dopamine deficiency.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Iron participates in the enzyme itself, and its local environment matters.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Iron coordination geometry in full-length, truncated, and dehydrated forms of human tyrosine hydroxylase studied by Mössbauer and X-ray absorption spectroscopy. · 1999 · https://pubmed.ncbi.nlm.nih.gov/10499095/ · DOI 10.1007/s007750050308","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"673dc73a-1d61-52a1-86f8-5eb6e0d111a4","evidence_kind":"source_excerpt","locator":"Lines 36-42","start_line":36,"end_line":42,"excerpt":"## l-tyrosine-th-iron\nIron participates in the enzyme itself, and its local environment matters.\nReconstituted human TH1 contained high-spin Fe(II); dehydration changed iron coordination and rehydration reversed the spectroscopic change.\nModel: Purified full-length and truncated human TH1; Mossbauer and X-ray absorption spectroscopy.\nLimitations: A hydration-dependent structural change is not evidence that ordinary dehydration causes dopamine deficiency.\nEvidence access: Primary abstract\nIron coordination geometry in full-length, truncated, and dehydrated forms of human tyrosine hydroxylase studied by Mössbauer and X-ray absorption spectroscopy. · 1999 · https://pubmed.ncbi.nlm.nih.gov/10499095/ · DOI 10.1007/s007750050308","model_system":"Purified full-length and truncated human TH1; Mossbauer and X-ray absorption spectroscopy.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"12917df2-c6e0-5b61-850f-dbff6d4b4d30","stable_key":"import-63ce713e-6aea-59f6-9896-ca30e010b2ce","title":"L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"7777f4440a8bfb14a04ff73e73392ccc45d8ee89f7853ecbcc0027d6f563b8a0","revision_id":"e1206111-3a75-5809-b8e9-231ff809ff1e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}