{"id":"ed3d9bb0-4115-5faf-aab1-94cfb8c710c8","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ver-peroxide-removal-iron-burst","predicate":"prevents","statement":"GSH/PHGPX pretreatment completely suppressed the subsequent radical-peroxidation burst when photooxidized erythrocyte ghosts were challenged with ascorbate/iron or xanthine/xanthine-oxidase/iron.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"00d123b2-8c62-55f1-b3d7-878e15f14694","mechanism_event_label":"Removing membrane hydroperoxides prevented an iron-driven burst of further oxidation.","subject":{"id":"e9bb13ee-f238-51e6-9101-78ddfd11465c","slug":"gpx4","display_name":"GPX4","entity_type_key":"protein"},"object":{"id":"f00627d2-4857-5c63-81af-71cde3768d38","slug":"lipid-peroxidation","display_name":"Lipid peroxidation","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"00d123b2-8c62-55f1-b3d7-878e15f14694","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ver-peroxide-removal-iron-burst-event","event_type":"biochemical_relationship","label":"Removing membrane hydroperoxides prevented an iron-driven burst of further oxidation.","description":"GSH/PHGPX pretreatment completely suppressed the subsequent radical-peroxidation burst when photooxidized erythrocyte ghosts were challenged with ascorbate/iron or xanthine/xanthine-oxidase/iron.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b44c9e27-4bbb-52d3-a022-14cddded5073","slug":"glutathione","display_name":"GSH","entity_type_key":"small_molecule"},"role":"reducing cosubstrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"38d0c4d9-53d1-5239-bfe3-c1b5e9b79085","slug":"ascorbate","display_name":"L-Ascorbate","entity_type_key":"small_molecule"},"role":"one experimental challenge component","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"experimental iron; oxidation state not assigned from abstract","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"5b200520-e015-50ee-8fbf-e0e0707296f1","slug":"phospholipid-hydroperoxides","display_name":"Phospholipid hydroperoxides","entity_type_key":"lipid"},"role":"removed substrates","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"e9bb13ee-f238-51e6-9101-78ddfd11465c","slug":"gpx4","display_name":"GPX4","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"f00627d2-4857-5c63-81af-71cde3768d38","slug":"lipid-peroxidation","display_name":"Lipid peroxidation","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Sequential peroxide reduction and iron challenge","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Photoperoxidation → GSH/PHGPX → iron-dependent challenge.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Ascorbate participates in this deliberately pro-oxidizing assay; this is not evidence that normal vitamin C intake damages membranes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin E research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-e","display_name":"Vitamin E","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Human-derived cell-free membranes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Removing membrane hydroperoxides prevented an iron-driven burst of further oxidation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ver-thomas1990] Protective action of phospholipid hydroperoxide glutathione peroxidase against membrane-damaging lipid peroxidation. In situ reduction of phospholipid and cholesterol hydroperoxides. (1990). https://pubmed.ncbi.nlm.nih.gov/2294113/ DOI: 10.1016/s0021-9258(19)40252-4","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Erythrocyte ghosts","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a5eaa75f-0d14-558c-bf47-47c9d7753699","evidence_kind":"source_excerpt","locator":"Lines 578-590","start_line":578,"end_line":590,"excerpt":"### ver-peroxide-removal-iron-burst\nGSH/PHGPX pretreatment completely suppressed the subsequent radical-peroxidation burst when photooxidized erythrocyte ghosts were challenged with ascorbate/iron or xanthine/xanthine-oxidase/iron.\nCondition category: normal\nnutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Removing membrane hydroperoxides prevented an iron-driven burst of further oxidation.\norganism: Human-derived cell-free membranes\ntissue_or_cell_type: Erythrocyte ghosts\nexperimental_model: Sequential peroxide reduction and iron challenge\nlimitations: Ascorbate participates in this deliberately pro-oxidizing assay; this is not evidence that normal vitamin C intake damages membranes.\nexposure: Photoperoxidation → GSH/PHGPX → iron-dependent challenge.\ncross_nutrient: true\nevidence_location: Primary abstract\n[ver-thomas1990] Protective action of phospholipid hydroperoxide glutathione peroxidase against membrane-damaging lipid peroxidation. 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