{"id":"b794ed36-7b5f-543d-bffc-b1ef657ae12e","stable_key":"335be270-ea4a-5c8e-ad04-964fd22a439e:vanadium-tf-cycle","predicate":"alters","statement":"Vanadium binding did not increase transferrin affinity for TfR1 at pH 7.4, but disrupted conformational changes at pH 5.6 with citrate in the transferrin-cycle model.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"017d3cbd-a9fb-5b72-bed7-80da98168b50","mechanism_event_label":"Receptor recognition and release during endosomal processing are different steps.","subject":{"id":"bf79be92-557a-54b3-8f78-7174ed04675d","slug":"human-vanadium-bound-transferrin","display_name":"Human transferrin bound to vanadium(V/IV)","entity_type_key":"protein_state"},"object":{"id":"1b3dda4a-350c-5c33-a08b-9a3e39f2578f","slug":"human-vanadium-transferrin-endosomal-conformation","display_name":"Endosome-like conformational change of vanadium-bound human transferrin","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"017d3cbd-a9fb-5b72-bed7-80da98168b50","stable_key":"335be270-ea4a-5c8e-ad04-964fd22a439e:vanadium-tf-cycle-event","event_type":"observed_relationship","label":"Receptor recognition and release during endosomal processing are different steps.","description":"Vanadium binding did not increase transferrin affinity for TfR1 at pH 7.4, but disrupted conformational changes at pH 5.6 with citrate in the transferrin-cycle model.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"bf79be92-557a-54b3-8f78-7174ed04675d","slug":"human-vanadium-bound-transferrin","display_name":"Human transferrin bound to vanadium(V/IV)","entity_type_key":"protein_state"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"1b3dda4a-350c-5c33-a08b-9a3e39f2578f","slug":"human-vanadium-transferrin-endosomal-conformation","display_name":"Endosome-like conformational change of vanadium-bound human transferrin","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c5cbad45-22c6-594b-ab6b-71880dab1b24","slug":"vanadium","display_name":"Vanadium","entity_type_key":"nutrient_element"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"05415b89-a435-5940-a9ba-b587a0b6f04d","slug":"tfrc","display_name":"Human transferrin receptor 1 / TFRC","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"ac656bc2-967c-568b-b6d5-58c7ff433c94","slug":"tf","display_name":"Human serum transferrin / TF","entity_type_key":"protein"},"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":"Biolayer interferometry and electrophoretic model of the human transferrin cycle.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Return of undissociated V–transferrin to the surface is the authors’ proposed explanation, not directly imaged trafficking.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vanadium collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vanadium","display_name":"Vanadium","entity_type_key":"nutrient_element"}},{"dimension":"plain_language","value_text":"Receptor recognition and release during endosomal processing are different steps.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Vanadium(V/IV)-Transferrin Binding Disrupts the Transferrin Cycle and Reduces Vanadium Uptake and Antiproliferative Activity in Human Lung Cancer Cells. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32578416/ · DOI 10.1021/acs.inorgchem.0c00926","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"ed4b2c76-9e99-514d-9dd9-1b34ff698a52","evidence_kind":"source_excerpt","locator":"Lines 206-212","start_line":206,"end_line":212,"excerpt":"## vanadium-tf-cycle\nReceptor recognition and release during endosomal processing are different steps.\nVanadium binding did not increase transferrin affinity for TfR1 at pH 7.4, but disrupted conformational changes at pH 5.6 with citrate in the transferrin-cycle model.\nModel: Biolayer interferometry and electrophoretic model of the human transferrin cycle.\nLimitations: Return of undissociated V–transferrin to the surface is the authors’ proposed explanation, not directly imaged trafficking.\nEvidence access: Primary abstract\nVanadium(V/IV)-Transferrin Binding Disrupts the Transferrin Cycle and Reduces Vanadium Uptake and Antiproliferative Activity in Human Lung Cancer Cells. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32578416/ · DOI 10.1021/acs.inorgchem.0c00926","model_system":"Biolayer interferometry and electrophoretic model of the human transferrin cycle.","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":"e4d5d0ba-529b-540f-96ed-e719d116ccfd","stable_key":"import-335be270-ea4a-5c8e-ad04-964fd22a439e","title":"Vanadium: speciation, phosphate-sensitive enzymes 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":"d36b30d972e756ca4d19b66f976980e206c65025bd4bbf4c127c17320bd019c2","revision_id":"70d42967-8032-5627-8670-f59841735e89","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}