{"id":"9aca603b-44af-5edc-9ff6-15895a56361a","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:vc-enzyme-dbh-coordination-scott-interpretation","predicate":"associated-with-reported-coordination-change","statement":"Scott et al. interpreted the ascorbate-reduced bovine DBH spectrum as a decrease from roughly four to two N/O ligands plus a sulfur-containing ligand at 2.30 angstrom, compared with the oxidized enzyme.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"3701c653-d31f-58af-ab09-da2d0630799c","mechanism_event_label":"This study proposed that reducing the copper also changed which nearby atoms coordinated it.","subject":{"id":"38d0c4d9-53d1-5239-bfe3-c1b5e9b79085","slug":"ascorbate","display_name":"L-Ascorbate","entity_type_key":"small_molecule"},"object":{"id":"07dd98e9-f18a-5187-83bb-d2f1f10605f4","slug":"bovine-dbh-cu-i-state","display_name":"Ascorbate-reduced bovine dopamine beta-hydroxylase","entity_type_key":"protein_state"},"evidence_count":1,"mechanism_event":{"id":"3701c653-d31f-58af-ab09-da2d0630799c","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:vc-enzyme-dbh-coordination-scott-interpretation-event","event_type":"observed_intervention","label":"This study proposed that reducing the copper also changed which nearby atoms coordinated it.","description":"Scott et al. interpreted the ascorbate-reduced bovine DBH spectrum as a decrease from roughly four to two N/O ligands plus a sulfur-containing ligand at 2.30 angstrom, compared with the oxidized enzyme.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"38d0c4d9-53d1-5239-bfe3-c1b5e9b79085","slug":"ascorbate","display_name":"L-Ascorbate","entity_type_key":"small_molecule"},"role":"supporting-reductant","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"78df2518-5479-5765-98cd-56c63f91d2a4","slug":"bovine-dbh","display_name":"Bovine dopamine beta-hydroxylase","entity_type_key":"protein"},"role":"assayed-protein","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"07dd98e9-f18a-5187-83bb-d2f1f10605f4","slug":"bovine-dbh-cu-i-state","display_name":"Ascorbate-reduced bovine dopamine beta-hydroxylase","entity_type_key":"protein_state"},"role":"interpreted-product-state","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Vitamin C chemistry in collagen, modified-lysine/carnitine metabolism or copper-dependent peptide/catecholamine processing.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Bovine dopamine beta-hydroxylase X-ray absorption and EXAFS","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Purified oxidized versus ascorbate-reduced bovine DBH; bulk X-ray absorption/EXAFS interpretation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Historical average EXAFS interpretation explicitly challenged by Blumberg1989; not an endorsed ligand assignment or a claim about human dietary copper.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin C research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-c","display_name":"Vitamin C","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Bos taurus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"This study proposed that reducing the copper also changed which nearby atoms coordinated it.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[scott1988] The copper sites of dopamine beta-hydroxylase: an X-ray absorption spectroscopic study. (1988). https://pubmed.ncbi.nlm.nih.gov/3179263/ DOI: 10.1021/bi00415a005","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Adrenal-medullary enzyme preparation","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"1decf2ea-8d10-5082-a755-41e836bb4528","evidence_kind":"source_excerpt","locator":"Lines 937-948","start_line":937,"end_line":948,"excerpt":"### vc-enzyme-dbh-coordination-scott-interpretation\nScott et al. interpreted the ascorbate-reduced bovine DBH spectrum as a decrease from roughly four to two N/O ligands plus a sulfur-containing ligand at 2.30 angstrom, compared with the oxidized enzyme.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: This study proposed that reducing the copper also changed which nearby atoms coordinated it.\norganism: Bos taurus\ntissue_or_cell_type: Adrenal-medullary enzyme preparation\nexperimental_model: Bovine dopamine beta-hydroxylase X-ray absorption and EXAFS\nlimitations: Historical average EXAFS interpretation explicitly challenged by Blumberg1989; not an endorsed ligand assignment or a claim about human dietary copper.\ncross_nutrient: Vitamin C chemistry in collagen, modified-lysine/carnitine metabolism or copper-dependent peptide/catecholamine processing.\nexposure: Purified oxidized versus ascorbate-reduced bovine DBH; bulk X-ray absorption/EXAFS interpretation.\n[scott1988] The copper sites of dopamine beta-hydroxylase: an X-ray absorption spectroscopic study. (1988). https://pubmed.ncbi.nlm.nih.gov/3179263/ DOI: 10.1021/bi00415a005","model_system":"Bovine dopamine beta-hydroxylase X-ray absorption and EXAFS","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [scott1988] The copper sites of dopamine beta-hydroxylase: an X-ray absorption spectroscopic study. (1988). https://pubmed.ncbi.nlm.nih.gov/3179263/ DOI: 10.1021/bi00415a005","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"fa811221-13bd-5c10-adc1-eaf097c7703c","stable_key":"import-cb568d28-484a-5c2e-9fcc-2d780358e514","title":"Vitamin C: mechanisms, 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":"b7fd83f956abb81855f2ea23199ba14e465cd91f4a2ac560277ec21ddafd7bfc","revision_id":"6cde9bbb-d712-5746-82a6-85b144253efa","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"53f19e17-8482-5f36-bf79-19fef7345710","title":"Historical DBH spectroscopy: does ascorbate reduction change copper ligation?","kind":"contradiction","status":"open","why":"The 1988 and 1989 bovine-enzyme studies agree on Cu(II)-to-Cu(I) reduction but explicitly disagree about average ligand number and sulfur/heavy-atom ligation in the reduced state. This is a published structural interpretation disagreement, not an error correction in this ledger.","resolution":"Preserve the agreed redox reaction separately. Compare sample preparation, heterogeneous copper sites and spectral fitting when evaluating the historical models; those are questions to investigate, not demonstrated explanations here. Later structural literature has not been comprehensively reviewed in this entry, so it does not assert that the historical dispute remains the current scientific consensus.","created_at":"2026-09-17 12:19:14","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/53f19e17-8482-5f36-bf79-19fef7345710","sides":[{"conflict_id":"53f19e17-8482-5f36-bf79-19fef7345710","ordinal":0,"label":"1988: changed N/O coordination and an added sulfur ligand","revision_id":"6cde9bbb-d712-5746-82a6-85b144253efa","start_line":937,"end_line":948,"quote":"### vc-enzyme-dbh-coordination-scott-interpretation\nScott et al. interpreted the ascorbate-reduced bovine DBH spectrum as a decrease from roughly four to two N/O ligands plus a sulfur-containing ligand at 2.30 angstrom, compared with the oxidized enzyme.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: This study proposed that reducing the copper also changed which nearby atoms coordinated it.\norganism: Bos taurus\ntissue_or_cell_type: Adrenal-medullary enzyme preparation\nexperimental_model: Bovine dopamine beta-hydroxylase X-ray absorption and EXAFS\nlimitations: Historical average EXAFS interpretation explicitly challenged by Blumberg1989; not an endorsed ligand assignment or a claim about human dietary copper.\ncross_nutrient: Vitamin C chemistry in collagen, modified-lysine/carnitine metabolism or copper-dependent peptide/catecholamine processing.\nexposure: Purified oxidized versus ascorbate-reduced bovine DBH; bulk X-ray absorption/EXAFS interpretation.\n[scott1988] The copper sites of dopamine beta-hydroxylase: an X-ray absorption spectroscopic study. (1988). https://pubmed.ncbi.nlm.nih.gov/3179263/ DOI: 10.1021/bi00415a005","source_key":"import-cb568d28-484a-5c2e-9fcc-2d780358e514","source_title":"Vitamin C: mechanisms, deficiency and nutrient interactions (2026-09-17)","claim_ids":["9aca603b-44af-5edc-9ff6-15895a56361a"]},{"conflict_id":"53f19e17-8482-5f36-bf79-19fef7345710","ordinal":1,"label":"1989: little average coordination change and no heavy-atom ligand","revision_id":"6cde9bbb-d712-5746-82a6-85b144253efa","start_line":950,"end_line":961,"quote":"### vc-enzyme-dbh-coordination-blumberg-interpretation\nBlumberg et al. found little average coordination change after ascorbate reduction: four nitrogen ligands best fit both forms, at 1.97 angstrom oxidized and 2.05 angstrom reduced; they found no sulfur or chlorine ligation and explicitly opposed the earlier interpretation.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The later study agreed that copper was reduced but interpreted the surrounding atoms differently.\norganism: Bos taurus\ntissue_or_cell_type: Adrenal-medullary enzyme preparation\nexperimental_model: Bovine dopamine beta-hydroxylase X-ray absorption and EXAFS\nlimitations: The abstract permits N/O ligation generally; four nitrogens was its best fit. Historical bulk spectroscopy, not a review of all later structural evidence or current consensus.\ncross_nutrient: Vitamin C chemistry in collagen, modified-lysine/carnitine metabolism or copper-dependent peptide/catecholamine processing.\nexposure: Purified oxidized versus ascorbate-reduced bovine DBH; bulk X-ray absorption/EXAFS interpretation.\n[blumberg1989] X-ray absorption spectroscopic study of the active copper sites in dopamine beta-hydroxylase. (1989). https://pubmed.ncbi.nlm.nih.gov/2703478/ DOI: 10.1016/s0021-9258(18)83307-5","source_key":"import-cb568d28-484a-5c2e-9fcc-2d780358e514","source_title":"Vitamin C: mechanisms, deficiency and nutrient interactions (2026-09-17)","claim_ids":["535e7a14-668d-5a41-b386-51d5d7f9faec"]}]}],"corrections":[],"research":null}