{"id":"92846a32-2f6e-5c32-8255-1a443de663cc","stable_key":"79018983-9179-5c1a-8e7a-d6f47a13582b:ki-lpo-substrate-block","predicate":"inhibits","statement":"Preincubating LPO with ammonium iodide decreased measured catalytic activity and stabilized a peroxide–iodide ternary complex.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"bad26c48-a2d2-58ae-ba1e-15ef67612a09","mechanism_event_label":"Iodide can inhibit the enzyme under a different order of exposure.","subject":{"id":"83b11ca6-52c7-5a1b-8c39-d9cdf89244e3","slug":"iodide","display_name":"Iodide ion","entity_type_key":"ion"},"object":{"id":"ae57b6a5-04e5-512c-bdad-87430178a058","slug":"lpo-catalytic-activity","display_name":"Lactoperoxidase catalytic activity","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"bad26c48-a2d2-58ae-ba1e-15ef67612a09","stable_key":"79018983-9179-5c1a-8e7a-d6f47a13582b:ki-lpo-substrate-block-event","event_type":"observed_relationship","label":"Iodide can inhibit the enzyme under a different order of exposure.","description":"Preincubating LPO with ammonium iodide decreased measured catalytic activity and stabilized a peroxide–iodide ternary complex.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"83b11ca6-52c7-5a1b-8c39-d9cdf89244e3","slug":"iodide","display_name":"Iodide ion","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"ae57b6a5-04e5-512c-bdad-87430178a058","slug":"lpo-catalytic-activity","display_name":"Lactoperoxidase catalytic activity","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"3d671567-4fb6-5b5f-a328-156987d5b396","slug":"lactoperoxidase-family","display_name":"Lactoperoxidase enzyme family","entity_type_key":"protein_family"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"da9d64bc-69d4-5d97-90a4-8f0ed03e0ac8","slug":"hydrogen-peroxide","display_name":"Hydrogen peroxide","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Purified LPO crystallography and activity assays; ammonium iodide supplied the anion, not KI.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure_category","value_text":"Study-specific exposure, including pharmacological and in-vitro conditions; normal is the schema fallback outside the three availability categories.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Structural/biochemical model; enzyme species not assigned from abstract. Cofactor chemistry does not establish dietary iron responsiveness.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Potassium iodide research collection; shared-anion and comparator studies are not all KI interventions.","comparator":null,"unit":null,"notes":"","entity":{"slug":"potassium-iodide","display_name":"Potassium iodide","entity_type_key":"chemical_species"}},{"dimension":"plain_language","value_text":"Iodide can inhibit the enzyme under a different order of exposure.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structure of a ternary complex of lactoperoxidase with iodide and hydrogen peroxide at 1.77 Å resolution. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33882424/ · DOI 10.1016/j.jinorgbio.2021.111461","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"fa56c4b6-fe9c-5e96-8953-501d1dd602f2","evidence_kind":"source_excerpt","locator":"Lines 224-230","start_line":224,"end_line":230,"excerpt":"## ki-lpo-substrate-block\nIodide can inhibit the enzyme under a different order of exposure.\nPreincubating LPO with ammonium iodide decreased measured catalytic activity and stabilized a peroxide–iodide ternary complex.\nModel: Purified LPO crystallography and activity assays; ammonium iodide supplied the anion, not KI.\nLimitations: Structural/biochemical model; enzyme species not assigned from abstract. Cofactor chemistry does not establish dietary iron responsiveness.\nEvidence location: Primary abstract\nStructure of a ternary complex of lactoperoxidase with iodide and hydrogen peroxide at 1.77 Å resolution. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33882424/ · DOI 10.1016/j.jinorgbio.2021.111461","model_system":"Purified LPO crystallography and activity assays; ammonium iodide supplied the anion, not KI.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Curation paraphrase; primary evidence location and source kind retained above.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dc3ce411-f68f-5eb8-87c1-1592665f9cb6","stable_key":"import-79018983-9179-5c1a-8e7a-d6f47a13582b","title":"Potassium iodide: thyroid and non-thyroid mechanisms, interactions and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-study references, chemical references and label statements individually identified. 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