{"id":"abebffde-3301-5109-b991-f2afa294c00b","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zinc-trans-znt1-low-ph-conformations","predicate":"changes_conformational_distribution_of","statement":"Human ZnT1 purified with zinc at pH 6.0 yielded inward-facing, outward-facing and mixed dimers, whereas the pH 7.5 zinc-bound structure was outward-facing; the authors interpreted structures and simulations as supporting proton-dependent zinc release.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"b60e2b0e-2605-59c1-a563-a48583a4dee0","mechanism_event_label":"Acidity changed the shapes captured for human ZnT1, informing one proposed export mechanism.","subject":{"id":"1ed0233a-3d10-58b3-abda-8ad04545c495","slug":"proton","display_name":"Proton","entity_type_key":"ion"},"object":{"id":"351a7f2b-7ed1-58c1-8c17-e6d520999c05","slug":"slc30a1","display_name":"Human ZnT1 (SLC30A1)","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"b60e2b0e-2605-59c1-a563-a48583a4dee0","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zinc-trans-znt1-low-ph-conformations-event","event_type":"biochemical_relationship","label":"Acidity changed the shapes captured for human ZnT1, informing one proposed export mechanism.","description":"Human ZnT1 purified with zinc at pH 6.0 yielded inward-facing, outward-facing and mixed dimers, whereas the pH 7.5 zinc-bound structure was outward-facing; the authors interpreted structures and simulations as supporting proton-dependent zinc release.","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":"bound_substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"1ed0233a-3d10-58b3-abda-8ad04545c495","slug":"proton","display_name":"Proton","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"351a7f2b-7ed1-58c1-8c17-e6d520999c05","slug":"slc30a1","display_name":"Human ZnT1 (SLC30A1)","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Wild-type human ZnT1 cryo-EM, biochemical assays and molecular dynamics","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Cryo-EM preparations with 1 mM zinc at pH 6.0 or pH 7.5.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Conformational snapshots and simulations do not directly quantify coupled proton flux or establish that calcium cannot couple transport. This record preserves observations and labels the interpretation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Zinc research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"zinc","display_name":"Zinc","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Acidity changed the shapes captured for human ZnT1, informing one proposed export mechanism.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[zinc-trans-39390258] Structural insights into human zinc transporter ZnT1 mediated Zn2+ efflux. (2024). https://pubmed.ncbi.nlm.nih.gov/39390258/ DOI: 10.1038/s44319-024-00287-3","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Detergent-solubilized purified membrane protein","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"372357eb-d72f-5c1d-a0f1-f9125ce2d4fb","evidence_kind":"source_excerpt","locator":"Lines 297-308","start_line":297,"end_line":308,"excerpt":"### zinc-trans-znt1-low-ph-conformations\nHuman ZnT1 purified with zinc at pH 6.0 yielded inward-facing, outward-facing and mixed dimers, whereas the pH 7.5 zinc-bound structure was outward-facing; the authors interpreted structures and simulations as supporting proton-dependent zinc release.\nCondition category: normal\nnutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Acidity changed the shapes captured for human ZnT1, informing one proposed export mechanism.\norganism: Homo sapiens protein\ntissue_or_cell_type: Detergent-solubilized purified membrane protein\nexperimental_model: Wild-type human ZnT1 cryo-EM, biochemical assays and molecular dynamics\nlimitations: Conformational snapshots and simulations do not directly quantify coupled proton flux or establish that calcium cannot couple transport. This record preserves observations and labels the interpretation.\nexposure: Cryo-EM preparations with 1 mM zinc at pH 6.0 or pH 7.5.\ncross_nutrient: false\n[zinc-trans-39390258] Structural insights into human zinc transporter ZnT1 mediated Zn2+ efflux. (2024). https://pubmed.ncbi.nlm.nih.gov/39390258/ DOI: 10.1038/s44319-024-00287-3","model_system":"Wild-type human ZnT1 cryo-EM, biochemical assays and molecular dynamics","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [zinc-trans-39390258] Structural insights into human zinc transporter ZnT1 mediated Zn2+ efflux. (2024). https://pubmed.ncbi.nlm.nih.gov/39390258/ DOI: 10.1038/s44319-024-00287-3","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"c5ee0fee-ce5c-58de-905a-10fb0ea0723c","stable_key":"import-6d38d43e-01e4-5641-93be-65654271e242","title":"Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"2e731dd54477ec1254e97df3323e1208d38f1375effed19252e71ab4f600d13a","revision_id":"c72258b9-ac09-5408-9d44-a921ad1f96a3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}