{"id":"c3144be3-ef9f-5fb8-acda-feee6f82852c","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:mthfs-folinic-acid-conversion","predicate":"converts","statement":"Purified human liver MTHFS converts 5-formyl-THF into 5,10-methenyl-THF.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"956c2729-bce4-51be-94ca-8a1feccfe19c","mechanism_event_label":"This enzyme moves folinic acid into the methenyl-folate pool.","subject":{"id":"9a1f2454-da04-5158-914f-e3d4d26c61b6","slug":"mthfs","display_name":"Human methenyltetrahydrofolate synthetase / MTHFS","entity_type_key":"protein"},"object":{"id":"bab4af27-0401-545c-aa8f-e945920e614b","slug":"5-formyltetrahydrofolate","display_name":"5-Formyltetrahydrofolate","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"956c2729-bce4-51be-94ca-8a1feccfe19c","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:mthfs-folinic-acid-conversion-event","event_type":"biochemical_relationship","label":"This enzyme moves folinic acid into the methenyl-folate pool.","description":"Purified human liver MTHFS converts 5-formyl-THF into 5,10-methenyl-THF.","status":"provisional","compartment":{"slug":"cytosol","display_name":"Cytosol"},"participants":[{"entity":{"id":"7978c99f-fb17-5d91-a9e4-178558bfa69f","slug":"5-10-methenyltetrahydrofolate","display_name":"5,10-Methenyltetrahydrofolate","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"9a1f2454-da04-5158-914f-e3d4d26c61b6","slug":"mthfs","display_name":"Human methenyltetrahydrofolate synthetase / MTHFS","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bab4af27-0401-545c-aa8f-e945920e614b","slug":"5-formyltetrahydrofolate","display_name":"5-Formyltetrahydrofolate","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Purified liver enzyme","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Purified human liver enzyme and folate substrates; initial-velocity measurements.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"An enzyme assay does not establish clinical benefit from folinic acid.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"folate","display_name":"Folate (vitamin B9)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"This enzyme moves folinic acid into the methenyl-folate pool.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Liver-derived, cell-free","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"7f2165ff-363f-5cc0-9207-76743c9634fc","evidence_kind":"source_excerpt","locator":"Lines 1243-1253","start_line":1243,"end_line":1253,"excerpt":"### mthfs-folinic-acid-conversion\nPurified human liver MTHFS converts 5-formyl-THF into 5,10-methenyl-THF.\nCondition category: normal\nnutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: This enzyme moves folinic acid into the methenyl-folate pool.\norganism: Homo sapiens\ntissue_or_cell_type: Liver-derived, cell-free\nexperimental_model: Purified liver enzyme\nlimitations: An enzyme assay does not establish clinical benefit from folinic acid.\nexposure: Purified human liver enzyme and folate substrates; initial-velocity measurements.\n[bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5","model_system":"Purified liver enzyme","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"f4ce1a62-9582-5f7a-84f5-a23d0e1bfc68","stable_key":"import-ec174d5a-4903-5745-8646-df0e9d4265e8","title":"Folate and folic acid: 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":"e564d43989ece1006c95cd0748e9af6fe369074599a2eebba0a99ebff864b0dd","revision_id":"76674a33-b2a1-5e41-b71b-44399038ff7c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}