{"id":"25f47676-d302-5225-b3a7-32f479898f64","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:human-tyms-magnesium-not-stimulatory","predicate":"does-not-enhance","statement":"Added magnesium did not enhance human TYMS reaction rates under conditions where bacterial TYMS differed.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"9dd89d48-6c21-55c8-ab41-32b4ce9cfbb7","mechanism_event_label":"Magnesium effects on bacterial enzymes cannot be assumed for human TYMS.","subject":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"object":{"id":"4787b939-16f1-56d3-8a66-acc5745625dd","slug":"tyms","display_name":"Human thymidylate synthase / TYMS","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"9dd89d48-6c21-55c8-ab41-32b4ce9cfbb7","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:human-tyms-magnesium-not-stimulatory-event","event_type":"biochemical_relationship","label":"Magnesium effects on bacterial enzymes cannot be assumed for human TYMS.","description":"Added magnesium did not enhance human TYMS reaction rates under conditions where bacterial TYMS differed.","status":"provisional","compartment":{"slug":"nucleus","display_name":"Nucleus"},"participants":[{"entity":{"id":"40631c80-c592-5f1e-89b3-fe8910f95b2b","slug":"dump","display_name":"Deoxyuridine monophosphate","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"4787b939-16f1-56d3-8a66-acc5745625dd","slug":"tyms","display_name":"Human thymidylate synthase / TYMS","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Species-specific boundary on a proposed magnesium-folate interaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Comparative enzyme kinetics","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Assay conditions described in the linked primary study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Assay-specific negative result, not proof of magnesium-independent DNA synthesis.","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":"Magnesium effects on bacterial enzymes cannot be assumed for human TYMS.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[islam-2018] Bacterial versus human thymidylate synthase: Kinetics and functionality (2018). https://pubmed.ncbi.nlm.nih.gov/29715278/ DOI: 10.1371/journal.pone.0196506","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"87a0cb78-ed19-5969-b6da-bfdb1c694b92","evidence_kind":"source_excerpt","locator":"Lines 985-996","start_line":985,"end_line":996,"excerpt":"### human-tyms-magnesium-not-stimulatory\nAdded magnesium did not enhance human TYMS reaction rates under conditions where bacterial TYMS differed.\nCondition category: normal\nnutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Magnesium effects on bacterial enzymes cannot be assumed for human TYMS.\norganism: Homo sapiens\ntissue_or_cell_type: Cell-free\nexperimental_model: Comparative enzyme kinetics\nlimitations: Assay-specific negative result, not proof of magnesium-independent DNA synthesis.\nexposure: Assay conditions described in the linked primary study.\ncross_nutrient: Species-specific boundary on a proposed magnesium-folate interaction.\n[islam-2018] Bacterial versus human thymidylate synthase: Kinetics and functionality (2018). https://pubmed.ncbi.nlm.nih.gov/29715278/ DOI: 10.1371/journal.pone.0196506","model_system":"Comparative enzyme kinetics","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [islam-2018] Bacterial versus human thymidylate synthase: Kinetics and functionality (2018). https://pubmed.ncbi.nlm.nih.gov/29715278/ DOI: 10.1371/journal.pone.0196506","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}