{"id":"f4d78653-ac32-5fab-90a0-c11d1b07de69","stable_key":"88eb7407-f147-558b-889b-0c89c4e0aa4a:spermidine-dhps-reversal","predicate":"regenerates","statement":"Purified human DHPS transferred radiolabeled aminobutyl from deoxyhypusine-eIF5A to 1,3-diaminopropane, regenerating spermidine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"80fd89ef-a5ca-5496-be61-e09f01e587e5","mechanism_event_label":"An unfinished protein modification can be reversed in vitro.","subject":{"id":"33684e20-5166-55d6-9196-0793156787f1","slug":"dhps","display_name":"DHPS","entity_type_key":"protein"},"object":{"id":"7014993c-468f-5c6b-ab04-80c87f9dfd9f","slug":"spermidine","display_name":"Spermidine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"80fd89ef-a5ca-5496-be61-e09f01e587e5","stable_key":"88eb7407-f147-558b-889b-0c89c4e0aa4a:spermidine-dhps-reversal-event","event_type":"observed_relationship","label":"An unfinished protein modification can be reversed in vitro.","description":"Purified human DHPS transferred radiolabeled aminobutyl from deoxyhypusine-eIF5A to 1,3-diaminopropane, regenerating spermidine.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"33684e20-5166-55d6-9196-0793156787f1","slug":"dhps","display_name":"DHPS","entity_type_key":"protein"},"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":"5120052e-17b6-5962-83aa-a365e4ae8a0c","slug":"1-3-diaminopropane","display_name":"1,3-Diaminopropane","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"283ed24b-06a1-50aa-9281-df3bac6ce37e","slug":"nad-plus","display_name":"NAD+","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"a4d54591-b5a7-5e54-a52c-7011ace70819","slug":"eif5a1-deoxyhypusine","display_name":"eIF5A1 with deoxyhypusine at residue 50","entity_type_key":"protein_state"},"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, NAD, labeled protein and diamine substrate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No in-vivo flux or dominant recycling contribution established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Spermidine collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"spermidine","display_name":"Spermidine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"An unfinished protein modification can be reversed in vitro.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Reversal of the deoxyhypusine synthesis reaction. Generation of spermidine or homospermidine from deoxyhypusine by deoxyhypusine synthase. · 2003 · https://pubmed.ncbi.nlm.nih.gov/12788913/ · DOI 10.1074/jbc.M304247200","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a2afdd8e-69ae-5aab-9ccb-25afda971500","evidence_kind":"source_excerpt","locator":"Lines 38-44","start_line":38,"end_line":44,"excerpt":"## spermidine-dhps-reversal\nAn unfinished protein modification can be reversed in vitro.\nPurified human DHPS transferred radiolabeled aminobutyl from deoxyhypusine-eIF5A to 1,3-diaminopropane, regenerating spermidine.\nModel: Human enzyme, NAD, labeled protein and diamine substrate.\nLimitations: No in-vivo flux or dominant recycling contribution established.\nEvidence access: Primary abstract\nReversal of the deoxyhypusine synthesis reaction. Generation of spermidine or homospermidine from deoxyhypusine by deoxyhypusine synthase. · 2003 · https://pubmed.ncbi.nlm.nih.gov/12788913/ · DOI 10.1074/jbc.M304247200","model_system":"Human enzyme, NAD, labeled protein and diamine substrate.","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":"4348f3f8-0180-58a3-b61c-55d03bb322d2","stable_key":"import-88eb7407-f147-558b-889b-0c89c4e0aa4a","title":"Spermidine: biosynthesis, hypusination, transport 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. 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