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This is the first reaction, before acetyl-CoA is made.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[seifert-2006-pdh-catalysis] Direct kinetic evidence for half-of-the-sites reactivity in the E1 component of the human pyruvate dehydrogenase multienzyme complex through alternating sites cofactor activation (2006). https://pubmed.ncbi.nlm.nih.gov/17042496/ DOI: 10.1021/bi061582l","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified mitochondrial enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"8fede7f3-7304-5d23-b82d-a5faf8e79f16","evidence_kind":"source_excerpt","locator":"Lines 663-674","start_line":663,"end_line":674,"excerpt":"### b1-pdh-pyruvate-covalent-decarboxylation\nHuman PDH E1 forms a covalent lactyl-ThDP intermediate from pyruvate and decarboxylates it, retaining the two-carbon fragment on ThDP.\nCondition category: normal\nnutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Activated vitamin B1 temporarily holds pyruvate while one carbon leaves as carbon dioxide. This is the first reaction, before acetyl-CoA is made.\norganism: Homo sapiens\ntissue_or_cell_type: Purified mitochondrial enzyme\nexperimental_model: Recombinant human E1; transient kinetics.\nlimitations: Purified-system evidence; nutritional response was not tested.\nevidence: [{\"paper_key\": \"seifert-2006-pdh-catalysis\", \"source_bundle\": \"artifacts/thiamine_metabolism_sources.json\", \"passage_ids\": [\"abstract\"], \"locator\": \"Primary publication abstract\", \"preservation\": \"Exact text retained in the source bundle; full source document retained when openly retrievable.\"}]\nnutrient: Thiamine (vitamin B1)\n[seifert-2006-pdh-catalysis] Direct kinetic evidence for half-of-the-sites reactivity in the E1 component of the human pyruvate dehydrogenase multienzyme complex through alternating sites cofactor activation (2006). https://pubmed.ncbi.nlm.nih.gov/17042496/ DOI: 10.1021/bi061582l","model_system":"Recombinant human E1; transient kinetics.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [seifert-2006-pdh-catalysis] Direct kinetic evidence for half-of-the-sites reactivity in the E1 component of the human pyruvate dehydrogenase multienzyme complex through alternating sites cofactor activation (2006). https://pubmed.ncbi.nlm.nih.gov/17042496/ DOI: 10.1021/bi061582l","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}