{"id":"bbe20cff-3876-5dac-9f2b-b07fbd01eb09","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:biotin-depletion-lowers-pcc","predicate":"depletion-reduces","statement":"In seven adults, 28-day egg-white-induced biotin depletion reduced mean lymphocyte PCC activity to 23% of baseline.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"7b8e7ecd-d556-5531-ae37-3da469335f1a","mechanism_event_label":"In this small depletion study, low biotin weakened a human enzyme upstream of B12-dependent metabolism.","subject":{"id":"37a8e96b-f95b-5ba7-a0bc-8ed3cfaf5fd8","slug":"biotin","display_name":"Biotin","entity_type_key":"small_molecule"},"object":{"id":"550bf033-5e88-53c0-b444-7cf27da452dc","slug":"human-lymphocyte-pcc-activity","display_name":"Human lymphocyte propionyl-CoA carboxylase activity","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7b8e7ecd-d556-5531-ae37-3da469335f1a","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:biotin-depletion-lowers-pcc-event","event_type":"biochemical_relationship","label":"In this small depletion study, low biotin weakened a human enzyme upstream of B12-dependent metabolism.","description":"In seven adults, 28-day egg-white-induced biotin depletion reduced mean lymphocyte PCC activity to 23% of baseline.","status":"provisional","compartment":{"slug":"mitochondrial-matrix","display_name":"Mitochondrial matrix"},"participants":[{"entity":{"id":"54eb0f2f-091c-54cd-b4a1-a528b994560a","slug":"human-propionyl-coa-carboxylase","display_name":"Human propionyl-CoA carboxylase / PCC","entity_type_key":"protein_complex"},"role":"affected-enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"37a8e96b-f95b-5ba7-a0bc-8ed3cfaf5fd8","slug":"biotin","display_name":"Biotin","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"550bf033-5e88-53c0-b444-7cf27da452dc","slug":"human-lymphocyte-pcc-activity","display_name":"Human lymphocyte propionyl-CoA carboxylase activity","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Primary abstract and indexed Results: PCC activity","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Seven healthy adults","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"28-day egg-white-rich biotin-depletion diet","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Lymphocyte enzyme activity; no concurrent B12 intervention or systemic pathway flux measurement.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"In this small depletion study, low biotin weakened a human enzyme upstream of B12-dependent metabolism.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[stratton-2006-biotin] Lymphocyte propionyl-CoA carboxylase and its activation by biotin are sensitive indicators of marginal biotin deficiency in humans. (2006). https://pubmed.ncbi.nlm.nih.gov/16895887/ DOI: 10.1093/ajcn/84.1.384","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Peripheral blood lymphocytes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"67182738-f05e-531c-a999-18c582a2fe57","evidence_kind":"source_excerpt","locator":"Lines 1202-1214","start_line":1202,"end_line":1214,"excerpt":"### biotin-depletion-lowers-pcc\nIn seven adults, 28-day egg-white-induced biotin depletion reduced mean lymphocyte PCC activity to 23% of baseline.\nCondition category: nutrient_deficiency\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: In this small depletion study, low biotin weakened a human enzyme upstream of B12-dependent metabolism.\norganism: Homo sapiens\ntissue_or_cell_type: Peripheral blood lymphocytes\nexperimental_model: Seven healthy adults\nlimitations: Lymphocyte enzyme activity; no concurrent B12 intervention or systemic pathway flux measurement.\nexposure: 28-day egg-white-rich biotin-depletion diet\ncross_nutrient: true\nevidence_location: Primary abstract and indexed Results: PCC activity\n[stratton-2006-biotin] Lymphocyte propionyl-CoA carboxylase and its activation by biotin are sensitive indicators of marginal biotin deficiency in humans. (2006). https://pubmed.ncbi.nlm.nih.gov/16895887/ DOI: 10.1093/ajcn/84.1.384","model_system":"Seven healthy adults","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [stratton-2006-biotin] Lymphocyte propionyl-CoA carboxylase and its activation by biotin are sensitive indicators of marginal biotin deficiency in humans. (2006). https://pubmed.ncbi.nlm.nih.gov/16895887/ DOI: 10.1093/ajcn/84.1.384","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"73145023-2982-5848-aff2-8d8875d6b9c5","stable_key":"import-7fc92b9e-9cbf-556e-8719-6b5244625250","title":"Vitamin B12: 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":"ad5b3a51d36e856aa7fdfd1cc23f690b094689bad87d28e1a621a54675a01c92","revision_id":"118bd616-0c13-549f-bfeb-bc439715b89c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}