{"id":"b5600168-defd-5600-a242-da66564cdeee","stable_key":"aaa7baba-8689-56ab-ba1e-b71542bcb8e9:iodine-syn-iyd-redox-switch","predicate":"stabilizes","statement":"The substrate analog 3-fluoro-L-tyrosine stabilized a one-electron-reduced FMN semiquinone during reductive titration of soluble human IYD.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"ac5a8d70-3769-56cb-b8c2-254062f698ad","mechanism_event_label":"Substrate-like binding changes which FMN redox state the enzyme can stabilize.","subject":{"id":"731980af-f8cb-5a6c-8680-97b8759962e1","slug":"fluorotyrosine","display_name":"3-Fluoro-L-tyrosine","entity_type_key":"small_molecule"},"object":{"id":"b26e8003-8524-58b0-8330-f969532a672a","slug":"fmn-semiquinone","display_name":"FMN semiquinone","entity_type_key":"chemical_species"},"evidence_count":1,"mechanism_event":{"id":"ac5a8d70-3769-56cb-b8c2-254062f698ad","stable_key":"aaa7baba-8689-56ab-ba1e-b71542bcb8e9:iodine-syn-iyd-redox-switch-event","event_type":"biochemical_relationship","label":"Substrate-like binding changes which FMN redox state the enzyme can stabilize.","description":"The substrate analog 3-fluoro-L-tyrosine stabilized a one-electron-reduced FMN semiquinone during reductive titration of soluble human IYD.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"10765e77-4f0b-5789-81c0-3ce11c80d583","slug":"human-iyd-delta-anchor","display_name":"Human IYD lacking N-terminal membrane anchor","entity_type_key":"protein_state"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d3eacf85-1a35-546d-bd30-161474dd9691","slug":"fmn","display_name":"Flavin mononucleotide","entity_type_key":"small_molecule"},"role":"redox_cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"FMN_vitamin_precursor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"731980af-f8cb-5a6c-8680-97b8759962e1","slug":"fluorotyrosine","display_name":"3-Fluoro-L-tyrosine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"b26e8003-8524-58b0-8330-f969532a672a","slug":"fmn-semiquinone","display_name":"FMN semiquinone","entity_type_key":"chemical_species"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/iodine-synthesis-sources/25395621.txt\", \"start_char\": 4223, \"end_char\": 4943, \"text_sha256\": \"5567eccc06be2559ce51e8a2640697678a8fd3c1216896997568a9341da5a73b\", \"text_characters\": 720, \"note\": \"Exact publisher passage retained in the cited local source cache; locator and digest supplied here.\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Reductive titration with versus without active-site ligand.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"An inert fluorotyrosine probe demonstrates cofactor control, not physiological fluoride displacement.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Iodine research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"iodine","display_name":"Iodine","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens recombinant protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Substrate-like binding changes which FMN redox state the enzyme can stabilize.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[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","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified soluble IYD","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"c1007edc-b7d2-5be0-b2ec-d32d78645f27","evidence_kind":"source_excerpt","locator":"Lines 716-728","start_line":716,"end_line":728,"excerpt":"### iodine-syn-iyd-redox-switch\nThe substrate analog 3-fluoro-L-tyrosine stabilized a one-electron-reduced FMN semiquinone during reductive titration of soluble human IYD.\nCondition category: normal\nnutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Substrate-like binding changes which FMN redox state the enzyme can stabilize.\norganism: Homo sapiens recombinant protein\ntissue_or_cell_type: Purified soluble IYD\nexperimental_model: Recombinant human IYD lacking residues 1–31; crystallography, radiotracer kinetics and redox titration\nlimitations: An inert fluorotyrosine probe demonstrates cofactor control, not physiological fluoride displacement.\nexposure: Reductive titration with versus without active-site ligand.\ncross_nutrient: true\nevidence_span: {\"source_cache\": \"artifacts/iodine-synthesis-sources/25395621.txt\", \"start_char\": 4223, \"end_char\": 4943, \"text_sha256\": \"5567eccc06be2559ce51e8a2640697678a8fd3c1216896997568a9341da5a73b\", \"text_characters\": 720, \"note\": \"Exact publisher passage retained in the cited local source cache; locator and digest supplied here.\"}\n[iodine-syn-iyd2015] A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate. 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