{"id":"3823e4a8-6507-57c2-ad5c-9fccdf3c1e63","stable_key":"be889add-cec8-500b-be89-676431432a70:mn-enz-sod2-redox-states","predicate":"cycles_between","statement":"Neutron structures of human SOD2 captured Mn(III) and Mn(II) states with coupled changes in active-site protonation.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"14e24e74-2558-5ce0-bebd-1e02548fc5e4","mechanism_event_label":"SOD2 changes manganese oxidation state as it transfers electrons and protons.","subject":{"id":"eda566c2-d338-54b2-a872-0dd39daffcdf","slug":"sod2","display_name":"Human mitochondrial manganese superoxide dismutase / SOD2","entity_type_key":"protein"},"object":{"id":"b252eb87-d778-59a0-a976-6db732773281","slug":"sod2-mn-iii-state","display_name":"Mn(III)-bound human SOD2","entity_type_key":"protein_state"},"evidence_count":1,"mechanism_event":{"id":"14e24e74-2558-5ce0-bebd-1e02548fc5e4","stable_key":"be889add-cec8-500b-be89-676431432a70:mn-enz-sod2-redox-states-event","event_type":"biochemical_relationship","label":"SOD2 changes manganese oxidation state as it transfers electrons and protons.","description":"Neutron structures of human SOD2 captured Mn(III) and Mn(II) states with coupled changes in active-site protonation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"eda566c2-d338-54b2-a872-0dd39daffcdf","slug":"sod2","display_name":"Human mitochondrial manganese superoxide dismutase / SOD2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"b252eb87-d778-59a0-a976-6db732773281","slug":"sod2-mn-iii-state","display_name":"Mn(III)-bound human SOD2","entity_type_key":"protein_state"},"role":"object","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"a8082b11-c484-5792-bb81-48e8e699cbe4","slug":"manganese-ion","display_name":"Mn2+","entity_type_key":"ion"},"role":"reduced cofactor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"cb5b9319-0f12-5260-974b-8f112d351451","slug":"manganese-iii-ion","display_name":"Manganese(III) ion","entity_type_key":"ion"},"role":"oxidized cofactor","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"e9e9bdb9-41ec-53dc-a632-d47f778c4fa1","slug":"sod2-mn-ii-state","display_name":"Mn(II)-bound human SOD2","entity_type_key":"protein_state"},"role":"reduced protein state","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Redox-controlled neutron structures of human SOD2","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Redox-controlled Mn(III) and Mn(II) crystals","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Primary experimental scope only; no human dietary threshold, clinical treatment rule, or universal metal substitution is established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Manganese research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"manganese","display_name":"Manganese","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"SOD2 changes manganese oxidation state as it transfers electrons and protons.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mn-enz-33824320] Direct detection of coupled proton and electron transfers in human manganese superoxide dismutase. (2021). https://pubmed.ncbi.nlm.nih.gov/33824320/ DOI: 10.1038/s41467-021-22290-1","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified enzyme; mitochondrial-matrix protein","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"7049568e-9cff-5fe5-b46d-cce3c21f89db","evidence_kind":"source_excerpt","locator":"Lines 422-432","start_line":422,"end_line":432,"excerpt":"### mn-enz-sod2-redox-states\nNeutron structures of human SOD2 captured Mn(III) and Mn(II) states with coupled changes in active-site protonation.\nCondition category: normal\nnutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: SOD2 changes manganese oxidation state as it transfers electrons and protons.\norganism: Homo sapiens\ntissue_or_cell_type: Purified enzyme; mitochondrial-matrix protein\nexperimental_model: Redox-controlled neutron structures of human SOD2\nlimitations: Primary experimental scope only; no human dietary threshold, clinical treatment rule, or universal metal substitution is established.\nexposure: Redox-controlled Mn(III) and Mn(II) crystals\n[mn-enz-33824320] Direct detection of coupled proton and electron transfers in human manganese superoxide dismutase. 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