{"id":"c627c7a7-327a-5a15-860c-26910b9e0620","stable_key":"18100170-a014-51c3-adeb-9dab4162b8cc:zinc-activation","predicate":"increases_in_recorded_experiment","statement":"Zinc addition restored classical thymulin rosette-bioassay activity after Chelex metal removal, with best activation at a 1:1 metal-to-peptide ratio.","claim_class":"mechanistic","status":"source_recorded","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"a604432c-9660-52d0-8d9d-3c758991f1a6","mechanism_event_label":"Zinc addition restored classical thymulin rosette-bioassay activity after Chelex metal removal, with best activation at a 1:1 metal-to-peptide ratio.","subject":{"id":"49c806c2-7041-5020-8b3b-fa04ffa122ac","slug":"zinc-ion","display_name":"Zinc(II) ion","entity_type_key":"ion"},"object":{"id":"23819462-9bdf-5856-beac-68b3dca9cf85","slug":"thymulin","display_name":"Thymulin","entity_type_key":"peptide"},"evidence_count":1,"mechanism_event":{"id":"a604432c-9660-52d0-8d9d-3c758991f1a6","stable_key":"18100170-a014-51c3-adeb-9dab4162b8cc:zinc-activation-event","event_type":"biochemical_relationship","label":"Zinc addition restored classical thymulin rosette-bioassay activity after Chelex metal removal, with best activation at a 1:1 metal-to-peptide ratio.","description":"In the foundational experiments, Chelex-mediated metal removal abolished rosette-bioassay activity, and zinc addition restored it. The best activation occurred at a 1:1 metal-to-peptide molar ratio; some other metals produced smaller recoveries. This establishes zinc-dependent activation under those conditions, not a claim that zinc is consumed with every signaling event or that all alternative complexes are inactive. [Dardenne et al., 1982](https://doi.org/10.1073/pnas.79.17.5370)","status":"provisional","compartment":null,"participants":[{"entity":{"id":"49c806c2-7041-5020-8b3b-fa04ffa122ac","slug":"zinc-ion","display_name":"Zinc(II) ion","entity_type_key":"ion"},"role":"tested factor","stoichiometry":null,"state_label":"Zinc addition to metal-depleted FTS","sequence_order":0,"notes":""},{"entity":{"id":"23819462-9bdf-5856-beac-68b3dca9cf85","slug":"thymulin","display_name":"Thymulin","entity_type_key":"peptide"},"role":"measured outcome","stoichiometry":null,"state_label":"increase","sequence_order":1,"notes":""},{"entity":{"id":"9bac7a31-4b5b-59f2-8dad-39269ddbb8b1","slug":"fts-peptide","display_name":"Zinc-free FTS nonapeptide component","entity_type_key":"peptide"},"role":"peptide substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary bibliographic record and abstract checked; full methods/figures not comprehensively reviewed.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_contrast","value_text":"{\"intervention\": \"Zinc addition to metal-depleted FTS\", \"comparator\": \"Metal-depleted FTS\", \"endpoint\": \"Zinc addition restored classical thymulin rosette-bioassay activity after Chelex metal removal, with best activation at a 1:1 metal-to-peptide ratio.\", \"effect_direction\": \"increase\", \"combination\": \"single\", \"conditions\": []}","comparator":null,"unit":null,"notes":"Explicit extracted experimental comparison; source-derived draft.","entity":null},{"dimension":"experimental_model","value_text":"Purified peptide and classical rosette bioassay; Chelex metal removal followed by metal reconstitution.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Interpret only within the recorded preparation, exposure and comparator. The complete source passage retains qualifications; unspecified doses/timing have not been extracted here. No clinical efficacy, nutrient deficiency or unique molecular mediation is inferred.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The peptide needs appropriate zinc association to be active in this assay; zinc is not shown to be consumed by signaling.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Contribution of zinc and other metals to the biological activity of the serum thymic factor. | 1982 | DOI 10.1073/pnas.79.17.5370 | PMID 6957870 | https://doi.org/10.1073/pnas.79.17.5370","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 23-23; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"15d458e5-2834-57d2-86b5-b3766c00a07a","evidence_kind":"source_excerpt","locator":"Lines 23-23","start_line":23,"end_line":23,"excerpt":"In the foundational experiments, Chelex-mediated metal removal abolished rosette-bioassay activity, and zinc addition restored it. The best activation occurred at a 1:1 metal-to-peptide molar ratio; some other metals produced smaller recoveries. This establishes zinc-dependent activation under those conditions, not a claim that zinc is consumed with every signaling event or that all alternative complexes are inactive. [Dardenne et al., 1982](https://doi.org/10.1073/pnas.79.17.5370)","model_system":"Purified peptide and classical rosette bioassay; Chelex metal removal followed by metal reconstitution.","directness":"reported_statement","verification_status":"source_recorded","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. Not a verbatim quotation from a primary paper.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"e1871d49-9c6b-547b-a1bb-6e2b9270ca89","stable_key":"import-18100170-a014-51c3-adeb-9dab4162b8cc","title":"Thymulin: detailed mechanisms of action (reviewed 3 October 2026)","document_type":"imported_text","citation_label":"Original AI-assisted review of primary studies and, where relevant, official regulatory records. Access level is retained per claim. Corrections, null results and unresolved questions remain explicit. Not publisher full text or independent replication.","file_path":"","sha256":"6e8ed0d7a5e23fc822f2ab418e0c4fb2411c01fcaa330039e8d7d93218cacc88","revision_id":"8c0e3449-9bbd-57c0-bb5e-de83f044f2ac","review_status":"source_recorded","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}