{"id":"d2e369da-b3ec-5345-aef4-14393b9202bf","stable_key":"46d15d9e-d3b5-544d-ba01-b785aa3e4f42:b1-ogdh-thdp-enamine-chemistry","predicate":"forms","statement":"Human recombinant OGDH reacted with 2-oxoglutarate to produce spectroscopic signals supporting a ThDP-bound post-decarboxylation enamine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"b09568a1-bef3-5d2f-86fe-f7badadaf399","mechanism_event_label":"At this TCA-cycle step, B1 holds the carbon fragment left after carbon dioxide loss. Bacterial stopped-flow numbers in the same paper are not human kinetic constants.","subject":{"id":"2fb34fcb-d648-52c6-ae1b-308d2b7acd05","slug":"ogdh","display_name":"Human 2-oxoglutarate dehydrogenase E1","entity_type_key":"protein"},"object":{"id":"c611dcc8-cb50-533d-a10b-90765e23ad65","slug":"ogdh-thdp-enamine","display_name":"OGDH-bound carboxypropylidene-ThDP enamine","entity_type_key":"chemical_species"},"evidence_count":1,"mechanism_event":{"id":"b09568a1-bef3-5d2f-86fe-f7badadaf399","stable_key":"46d15d9e-d3b5-544d-ba01-b785aa3e4f42:b1-ogdh-thdp-enamine-chemistry-event","event_type":"biochemical_relationship","label":"At this TCA-cycle step, B1 holds the carbon fragment left after carbon dioxide loss. Bacterial stopped-flow numbers in the same paper are not human kinetic constants.","description":"Human recombinant OGDH reacted with 2-oxoglutarate to produce spectroscopic signals supporting a ThDP-bound post-decarboxylation enamine.","status":"provisional","compartment":{"slug":"mitochondrial-matrix","display_name":"Mitochondrial matrix"},"participants":[{"entity":{"id":"628ddc2d-e4d9-59c7-ae76-0c0cab80a6b1","slug":"2-oxoglutarate","display_name":"2-Oxoglutarate","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"187db168-8028-5ce6-9f8b-4bc61ebad1a0","slug":"thiamine-diphosphate","display_name":"Thiamine diphosphate","entity_type_key":"small_molecule"},"role":"covalent catalyst","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"966f14e5-c82f-5535-ad89-bfcc0adb2232","slug":"carbon-dioxide","display_name":"Carbon dioxide","entity_type_key":"small_molecule"},"role":"decarboxylation product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2fb34fcb-d648-52c6-ae1b-308d2b7acd05","slug":"ogdh","display_name":"Human 2-oxoglutarate dehydrogenase E1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"c611dcc8-cb50-533d-a10b-90765e23ad65","slug":"ogdh-thdp-enamine","display_name":"OGDH-bound carboxypropylidene-ThDP enamine","entity_type_key":"chemical_species"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence","value_text":"[{\"paper_key\": \"nemeria-2014-ogdh\", \"source_bundle\": \"artifacts/thiamine_metabolism_sources.json\", \"passage_ids\": [\"p-48\"], \"locator\": \"CD titration of E1o-h\", \"preservation\": \"Exact text retained in the source bundle; full source document retained when openly retrievable.\"}]","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human OGDH circular dichroism and related spectroscopy.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Enamine assignment integrates spectroscopy and comparative experiments; fine kinetic rates were separately measured in E. coli.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient","value_text":"Thiamine (vitamin B1)","comparator":null,"unit":null,"notes":"","entity":{"slug":"thiamine","display_name":"Thiamine (vitamin B1)","entity_type_key":"small_molecule"}},{"dimension":"nutrient_topic","value_text":"Thiamine research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"thiamine","display_name":"Thiamine (vitamin B1)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"At this TCA-cycle step, B1 holds the carbon fragment left after carbon dioxide loss. Bacterial stopped-flow numbers in the same paper are not human kinetic constants.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[nemeria-2014-ogdh] Human 2-oxoglutarate dehydrogenase complex E1 component forms a thiamin-derived radical by aerobic oxidation of the enamine intermediate (2014). https://pubmed.ncbi.nlm.nih.gov/25210035/ DOI: 10.1074/jbc.m114.591073","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified E1","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"dd94ec99-2101-5074-b626-b1a3cddc3d3d","evidence_kind":"source_excerpt","locator":"Lines 842-853","start_line":842,"end_line":853,"excerpt":"### b1-ogdh-thdp-enamine-chemistry\nHuman recombinant OGDH reacted with 2-oxoglutarate to produce spectroscopic signals supporting a ThDP-bound post-decarboxylation enamine.\nCondition category: normal\nnutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: At this TCA-cycle step, B1 holds the carbon fragment left after carbon dioxide loss. Bacterial stopped-flow numbers in the same paper are not human kinetic constants.\norganism: Homo sapiens\ntissue_or_cell_type: Purified E1\nexperimental_model: Human OGDH circular dichroism and related spectroscopy.\nlimitations: Enamine assignment integrates spectroscopy and comparative experiments; fine kinetic rates were separately measured in E. coli.\nevidence: [{\"paper_key\": \"nemeria-2014-ogdh\", \"source_bundle\": \"artifacts/thiamine_metabolism_sources.json\", \"passage_ids\": [\"p-48\"], \"locator\": \"CD titration of E1o-h\", \"preservation\": \"Exact text retained in the source bundle; full source document retained when openly retrievable.\"}]\nnutrient: Thiamine (vitamin B1)\n[nemeria-2014-ogdh] Human 2-oxoglutarate dehydrogenase complex E1 component forms a thiamin-derived radical by aerobic oxidation of the enamine intermediate (2014). https://pubmed.ncbi.nlm.nih.gov/25210035/ DOI: 10.1074/jbc.m114.591073","model_system":"Human OGDH circular dichroism and related spectroscopy.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [nemeria-2014-ogdh] Human 2-oxoglutarate dehydrogenase complex E1 component forms a thiamin-derived radical by aerobic oxidation of the enamine intermediate (2014). https://pubmed.ncbi.nlm.nih.gov/25210035/ DOI: 10.1074/jbc.m114.591073","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"158d2c03-ac8c-589f-8270-c468165ae346","stable_key":"import-46d15d9e-d3b5-544d-ba01-b785aa3e4f42","title":"Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"f376512fb3310141315548015b387833e3af45146e73fb73cd02cee20e4ddb9c","revision_id":"53bc5eda-dec8-58cc-a56f-a9eb4ab036ef","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}