{"id":"9df9440e-e973-5cdc-aea8-ea4f58f28525","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-abs-food-haptocorrin-capture","predicate":"accepts","statement":"In egg-yolk transfer assays, human R binder accepted released cobalamin, whereas direct transfer to intrinsic factor was not detected and R-binder-deficient gastric juice failed to accept it.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"73ab07e5-ea0d-5cd5-bb37-be163f9f6ec8","mechanism_event_label":"The first observed carrier was haptocorrin.","subject":{"id":"21f01bdf-1da9-59c3-af35-c67281e89dd4","slug":"tcn1","display_name":"Human haptocorrin / TCN1","entity_type_key":"protein"},"object":{"id":"b6d9b937-895d-5e0a-8cc5-0454a0b7d373","slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"},"evidence_count":1,"mechanism_event":{"id":"73ab07e5-ea0d-5cd5-bb37-be163f9f6ec8","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-abs-food-haptocorrin-capture-event","event_type":"biochemical_relationship","label":"The first observed carrier was haptocorrin.","description":"In egg-yolk transfer assays, human R binder accepted released cobalamin, whereas direct transfer to intrinsic factor was not detected and R-binder-deficient gastric juice failed to accept it.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b6d9b937-895d-5e0a-8cc5-0454a0b7d373","slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"},"role":"nutrient","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"490161eb-b7f8-56b6-82bc-77c8c0bdc1ca","slug":"gif","display_name":"Human gastric intrinsic factor / GIF","entity_type_key":"protein"},"role":"tested-alternative-carrier","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"21f01bdf-1da9-59c3-af35-c67281e89dd4","slug":"tcn1","display_name":"Human haptocorrin / TCN1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"In vitro egg-yolk cobalamin-binding protein mixed with human saliva/gastric juice","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Acidified human saliva/gastric juice with egg-yolk-bound radiocobalamin","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Food-specific biochemical model; this pH threshold is not a clinical blood threshold or proof that all foods behave identically. Pepsin preparation species was not specified in the inspected abstract.","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":"The first observed carrier was haptocorrin.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[carmel-1990-food-transfer] Transfer of cobalamin from the cobalamin-binding protein of egg yolk to R binder of human saliva and gastric juice. (1990). https://pubmed.ncbi.nlm.nih.gov/2110915/ DOI: 10.1016/0016-5085(90)91076-i","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Gastric luminal digestion model","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cdc55b50-3c7a-5598-91e3-8e038c612f46","evidence_kind":"source_excerpt","locator":"Lines 114-125","start_line":114,"end_line":125,"excerpt":"### b12-abs-food-haptocorrin-capture\nIn egg-yolk transfer assays, human R binder accepted released cobalamin, whereas direct transfer to intrinsic factor was not detected and R-binder-deficient gastric juice failed to accept it.\nCondition category: normal\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The first observed carrier was haptocorrin.\norganism: Homo sapiens\ntissue_or_cell_type: Gastric luminal digestion model\nexperimental_model: In vitro egg-yolk cobalamin-binding protein mixed with human saliva/gastric juice\nlimitations: Food-specific biochemical model; this pH threshold is not a clinical blood threshold or proof that all foods behave identically. Pepsin preparation species was not specified in the inspected abstract.\nexposure: Acidified human saliva/gastric juice with egg-yolk-bound radiocobalamin\ncross_nutrient: false\n[carmel-1990-food-transfer] Transfer of cobalamin from the cobalamin-binding protein of egg yolk to R binder of human saliva and gastric juice. (1990). https://pubmed.ncbi.nlm.nih.gov/2110915/ DOI: 10.1016/0016-5085(90)91076-i","model_system":"In vitro egg-yolk cobalamin-binding protein mixed with human saliva/gastric juice","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [carmel-1990-food-transfer] Transfer of cobalamin from the cobalamin-binding protein of egg yolk to R binder of human saliva and gastric juice. (1990). https://pubmed.ncbi.nlm.nih.gov/2110915/ DOI: 10.1016/0016-5085(90)91076-i","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}