{"id":"6dae62e0-7485-5433-83a3-2a16738af193","stable_key":"ec987f3e-0b3c-55cc-b304-c703a738e35d:egcg-sult-cap","predicate":"inhibits","statement":"EGCG stabilized the closed SULT1A1 active-site cap, slowed nucleotide release and inhibited turnover; nucleotide-bound enzyme showed 17-fold tighter EGCG binding.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"f72aac52-98e5-5bc0-93f7-782d6273c76b","mechanism_event_label":"EGCG can trap this enzyme in a slower-cycling state.","subject":{"id":"22e1b8eb-f35f-5afa-be20-b0534df9f6be","slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"},"object":{"id":"77a2330c-c4ad-59f2-9c0e-67a508bfe20d","slug":"sult1a1","display_name":"Human sulfotransferase 1A1 / SULT1A1","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"f72aac52-98e5-5bc0-93f7-782d6273c76b","stable_key":"ec987f3e-0b3c-55cc-b304-c703a738e35d:egcg-sult-cap-event","event_type":"observed_relationship","label":"EGCG can trap this enzyme in a slower-cycling state.","description":"EGCG stabilized the closed SULT1A1 active-site cap, slowed nucleotide release and inhibited turnover; nucleotide-bound enzyme showed 17-fold tighter EGCG binding.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"22e1b8eb-f35f-5afa-be20-b0534df9f6be","slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"77a2330c-c4ad-59f2-9c0e-67a508bfe20d","slug":"sult1a1","display_name":"Human sulfotransferase 1A1 / SULT1A1","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Allosteric binding/kinetic model; weak active-site binding also observed.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Substrate status and inhibition are separate questions; not proof of altered melatonin or hormone levels in people.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"EGCG collection; comparator and shared-pathway records retain their actual intervention.","comparator":null,"unit":null,"notes":"","entity":{"slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"EGCG can trap this enzyme in a slower-cycling state.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Isozyme Specific Allosteric Regulation of Human Sulfotransferase 1A1. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27356022/ · DOI 10.1021/acs.biochem.6b00401","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"bc6c3f1d-a878-5f38-9cc2-a687ed9a7a7a","evidence_kind":"source_excerpt","locator":"Lines 308-314","start_line":308,"end_line":314,"excerpt":"## egcg-sult-cap\nEGCG can trap this enzyme in a slower-cycling state.\nEGCG stabilized the closed SULT1A1 active-site cap, slowed nucleotide release and inhibited turnover; nucleotide-bound enzyme showed 17-fold tighter EGCG binding.\nModel: Allosteric binding/kinetic model; weak active-site binding also observed.\nLimitations: Substrate status and inhibition are separate questions; not proof of altered melatonin or hormone levels in people.\nEvidence access: primary abstract.\nIsozyme Specific Allosteric Regulation of Human Sulfotransferase 1A1. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27356022/ · DOI 10.1021/acs.biochem.6b00401","model_system":"Allosteric binding/kinetic model; weak active-site binding also observed.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Primary-abstract paraphrase; no full-text methods verification claimed.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"1f6d09e8-3aae-5c41-9ea7-15d0d1cab72d","stable_key":"import-ec987f3e-0b3c-55cc-b304-c703a738e35d","title":"EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"b101c8d4d96ee03ff97eb1922c7bb0f96943295af473fdc3ef98b0dbd62fe8c7","revision_id":"e19bc5b2-ee3c-5f67-b5c5-9dc3b7d5f850","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}