{"id":"68d8762e-8ef8-511f-b979-8bea3b1acb16","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-pnmt-methyl","predicate":"produces","statement":"Human PNMT transfers a methyl group from SAM to norepinephrine during epinephrine synthesis.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7c25ad0c-1a00-50e1-b965-699fa9307961","mechanism_event_label":"A downstream branch uses a methyl donor from methionine metabolism.","subject":{"id":"78a8cce1-9450-51b5-b5a4-abde6ba456ee","slug":"pnmt","display_name":"Human phenylethanolamine N-methyltransferase / PNMT","entity_type_key":"protein"},"object":{"id":"7f5bdfe9-54d7-5cfc-86d9-10c23bdfa290","slug":"epinephrine","display_name":"Epinephrine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"7c25ad0c-1a00-50e1-b965-699fa9307961","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-pnmt-methyl-event","event_type":"observed_relationship","label":"A downstream branch uses a methyl donor from methionine metabolism.","description":"Human PNMT transfers a methyl group from SAM to norepinephrine during epinephrine synthesis.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"78a8cce1-9450-51b5-b5a4-abde6ba456ee","slug":"pnmt","display_name":"Human phenylethanolamine N-methyltransferase / PNMT","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"7f5bdfe9-54d7-5cfc-86d9-10c23bdfa290","slug":"epinephrine","display_name":"Epinephrine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"34ab29ee-eb2b-5e51-9d25-0c1f8d5b97d9","slug":"norepinephrine","display_name":"Norepinephrine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human enzyme transition-state and inhibitor kinetics; structural analysis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Shared SAM use does not prove that tyrosine supplementation drains folate, B12 or methionine.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A downstream branch uses a methyl donor from methionine metabolism.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Transition-State Analogues of Phenylethanolamine N-Methyltransferase. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32702980/ · DOI 10.1021/jacs.0c05446","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"6448d29e-f9f3-5779-bfda-555d1760732b","evidence_kind":"source_excerpt","locator":"Lines 44-50","start_line":44,"end_line":50,"excerpt":"## l-tyrosine-pnmt-methyl\nA downstream branch uses a methyl donor from methionine metabolism.\nHuman PNMT transfers a methyl group from SAM to norepinephrine during epinephrine synthesis.\nModel: Human enzyme transition-state and inhibitor kinetics; structural analysis.\nLimitations: Shared SAM use does not prove that tyrosine supplementation drains folate, B12 or methionine.\nEvidence access: Primary abstract\nTransition-State Analogues of Phenylethanolamine N-Methyltransferase. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32702980/ · DOI 10.1021/jacs.0c05446","model_system":"Human enzyme transition-state and inhibitor kinetics; structural analysis.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"12917df2-c6e0-5b61-850f-dbff6d4b4d30","stable_key":"import-63ce713e-6aea-59f6-9896-ca30e010b2ce","title":"L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"7777f4440a8bfb14a04ff73e73392ccc45d8ee89f7853ecbcc0027d6f563b8a0","revision_id":"e1206111-3a75-5809-b8e9-231ff809ff1e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}