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full source document retained when openly retrievable.\"}]","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human recombinant TKT; chemical quench and NMR.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Acid quench protonates the intermediate; native enamine occupancy is inferred from trapped species.","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":"B1 temporarily carries the two-carbon sugar fragment before its transfer to an acceptor; the detected acid-trapped form is distinguished from the reactive enamine.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mitschke-2010-tkt] The crystal structure of human transketolase and new insights into its mode of action (2010). https://pubmed.ncbi.nlm.nih.gov/20667822/ DOI: 10.1074/jbc.m110.149955","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"326b10a1-88e9-51b5-87cb-c479c71cf924","evidence_kind":"source_excerpt","locator":"Lines 963-974","start_line":963,"end_line":974,"excerpt":"### b1-tkt-dhe-thdp-intermediate\nAcid-quench NMR of human TKT identified the protonated form of the DHE-ThDP intermediate generated during the donor half-reaction.\nCondition category: normal\nnutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: B1 temporarily carries the two-carbon sugar fragment before its transfer to an acceptor; the detected acid-trapped form is distinguished from the reactive enamine.\norganism: Homo sapiens\ntissue_or_cell_type: Purified enzyme\nexperimental_model: Human recombinant TKT; chemical quench and NMR.\nlimitations: Acid quench protonates the intermediate; native enamine occupancy is inferred from trapped species.\nevidence: [{\"paper_key\": \"mitschke-2010-tkt\", \"source_bundle\": \"artifacts/thiamine_metabolism_sources.json\", \"passage_ids\": [\"p-31\", \"p-44\", \"p-46\", \"p-47\"], \"locator\": \"acid quench\", \"preservation\": \"Exact text retained in the source bundle; full source document retained when openly retrievable.\"}]\nnutrient: Thiamine (vitamin B1)\n[mitschke-2010-tkt] The crystal structure of human transketolase and new insights into its mode of action (2010). https://pubmed.ncbi.nlm.nih.gov/20667822/ DOI: 10.1074/jbc.m110.149955","model_system":"Human recombinant TKT; chemical quench and NMR.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mitschke-2010-tkt] The crystal structure of human transketolase and new insights into its mode of action (2010). https://pubmed.ncbi.nlm.nih.gov/20667822/ DOI: 10.1074/jbc.m110.149955","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}