{"id":"b0fb6185-8406-5a48-bb4f-3b5ccffc3ee7","stable_key":"fd37d270-3395-56d6-9f1c-ddda56e606f6:arg-srm","predicate":"converted_to","statement":"Human SRM uses putrescine as the amine acceptor for aminopropyl transfer from decarboxylated SAM.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"50331a1a-fdac-5e74-ba48-8f324a4384bc","mechanism_event_label":"Polyamine synthesis combines an ornithine-derived branch with a SAM-derived branch.","subject":{"id":"c71bf622-f14b-5314-b1a5-dfa002d2d8ff","slug":"putrescine","display_name":"Putrescine","entity_type_key":"small_molecule"},"object":{"id":"7014993c-468f-5c6b-ab04-80c87f9dfd9f","slug":"spermidine","display_name":"Spermidine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"50331a1a-fdac-5e74-ba48-8f324a4384bc","stable_key":"fd37d270-3395-56d6-9f1c-ddda56e606f6:arg-srm-event","event_type":"observed_relationship","label":"Polyamine synthesis combines an ornithine-derived branch with a SAM-derived branch.","description":"Human SRM uses putrescine as the amine acceptor for aminopropyl transfer from decarboxylated SAM.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"c71bf622-f14b-5314-b1a5-dfa002d2d8ff","slug":"putrescine","display_name":"Putrescine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"7014993c-468f-5c6b-ab04-80c87f9dfd9f","slug":"spermidine","display_name":"Spermidine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"aeceef7c-e66e-5da6-8491-0dc68ce2263e","slug":"srm","display_name":"Human spermidine synthase / SRM","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ae5a8bbb-59e5-503a-94c9-51b512d7c7b3","slug":"decarboxylated-sam","display_name":"Decarboxylated S-adenosylmethionine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human enzyme structural, biochemical and mutagenesis experiments.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This consumes an aminopropyl donor, not a direct methyl transfer from ordinary SAM.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Arginine collection; tissue, species, dose and formulation distinctions retained.","comparator":null,"unit":null,"notes":"","entity":{"slug":"arginine","display_name":"L-Arginine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Polyamine synthesis combines an ornithine-derived branch with a SAM-derived branch.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structure and mechanism of spermidine synthases. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17585781/ · DOI 10.1021/bi602498k","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"edb537fe-51d3-5c3d-b105-ecfab675b5ce","evidence_kind":"source_excerpt","locator":"Lines 134-140","start_line":134,"end_line":140,"excerpt":"## arg-srm\nPolyamine synthesis combines an ornithine-derived branch with a SAM-derived branch.\nHuman SRM uses putrescine as the amine acceptor for aminopropyl transfer from decarboxylated SAM.\nModel: Human enzyme structural, biochemical and mutagenesis experiments.\nLimitations: This consumes an aminopropyl donor, not a direct methyl transfer from ordinary SAM.\nEvidence access: Primary abstract\nStructure and mechanism of spermidine synthases. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17585781/ · DOI 10.1021/bi602498k","model_system":"Human enzyme structural, biochemical and mutagenesis experiments.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; primary evidence access stated per claim.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"bb9a67ea-904f-5b8a-93a4-459081212bdd","stable_key":"import-fd37d270-3395-56d6-9f1c-ddda56e606f6","title":"L-Arginine: transport, metabolic branches, nutrient interactions, availability and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"ec0e9a3fb72b7485534e4372a074ac7624a399ff962e55690eb462217b5149ec","revision_id":"af027270-5535-51ae-85ff-9c76c518c962","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}