{"id":"cdad9dbb-24b4-54fb-8c10-95c781c8f73c","stable_key":"44737fa3-b335-53f4-a644-b9878d4416ac:creatine-methionine-sam-supply","predicate":"is_adenylated_to","statement":"Methionine adenosylation supplies SAM, the methyl donor consumed when guanidinoacetate is converted to creatine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"a7962a8e-07d7-549f-9122-2af59a74800b","mechanism_event_label":"Methionine must first be activated into SAM before its methyl group can finish creatine synthesis.","subject":{"id":"9d39f561-740b-5f67-bba7-8a72ef612a99","slug":"methionine","display_name":"L-Methionine","entity_type_key":"small_molecule"},"object":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"a7962a8e-07d7-549f-9122-2af59a74800b","stable_key":"44737fa3-b335-53f4-a644-b9878d4416ac:creatine-methionine-sam-supply-event","event_type":"biochemical_relationship","label":"Methionine must first be activated into SAM before its methyl group can finish creatine synthesis.","description":"Methionine adenosylation supplies SAM, the methyl donor consumed when guanidinoacetate is converted to creatine.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f0c9960d-9098-5384-9db9-b71e851b462d","slug":"rat-methionine-adenosyltransferases","display_name":"Rat methionine adenosyltransferases (SAM-synthesis enzymes)","entity_type_key":"protein_family"},"role":"enzyme_group","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"84053a83-8fcc-5068-8df9-58f7e97fad76","slug":"guanidinoacetate","display_name":"Guanidinoacetate","entity_type_key":"small_molecule"},"role":"downstream_methyl_acceptor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9f5df558-ed3d-5cda-b5ca-0f90f7aa6a8c","slug":"creatine","display_name":"Creatine","entity_type_key":"small_molecule"},"role":"downstream_product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"9d39f561-740b-5f67-bba7-8a72ef612a99","slug":"methionine","display_name":"L-Methionine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/creatine-research/11595668.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"b195a8b17815bf7d9223831374e2f85ae2f90d8d74117ad7aa8d94af7a9e94b0\", \"start_char\": 0, \"end_char\": 1687, \"text_sha256\": \"b195a8b17815bf7d9223831374e2f85ae2f90d8d74117ad7aa8d94af7a9e94b0\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Rat methyl-demand feeding and hepatocyte experiments; reaction context from the primary report","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Guanidinoacetate, creatine and methionine exposures","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The reaction record preserves the biochemical context of this primary experiment; it does not establish a universal fraction of human methylation demand.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Creatine research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"creatine","display_name":"Creatine","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Rats","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Methionine must first be activated into SAM before its methyl group can finish creatine synthesis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[creatine-p11595668] Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate. (2001). https://pubmed.ncbi.nlm.nih.gov/11595668/ DOI: 10.1152/ajpendo.2001.281.5.e1095","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Liver and isolated hepatocytes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"b77313d2-d3a2-55ff-850e-7ccb1f49cad2","evidence_kind":"source_excerpt","locator":"Lines 217-228","start_line":217,"end_line":228,"excerpt":"### creatine-methionine-sam-supply\nMethionine adenosylation supplies SAM, the methyl donor consumed when guanidinoacetate is converted to creatine.\nCondition category: normal\nnutrient_topic: Creatine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Methionine must first be activated into SAM before its methyl group can finish creatine synthesis.\norganism: Rats\ntissue_or_cell_type: Liver and isolated hepatocytes\nexperimental_model: Rat methyl-demand feeding and hepatocyte experiments; reaction context from the primary report\nlimitations: The reaction record preserves the biochemical context of this primary experiment; it does not establish a universal fraction of human methylation demand.\nexposure: Guanidinoacetate, creatine and methionine exposures\nevidence_span: {\"source_cache\": \"artifacts/creatine-research/11595668.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"b195a8b17815bf7d9223831374e2f85ae2f90d8d74117ad7aa8d94af7a9e94b0\", \"start_char\": 0, \"end_char\": 1687, \"text_sha256\": \"b195a8b17815bf7d9223831374e2f85ae2f90d8d74117ad7aa8d94af7a9e94b0\"}\n[creatine-p11595668] Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate. (2001). https://pubmed.ncbi.nlm.nih.gov/11595668/ DOI: 10.1152/ajpendo.2001.281.5.e1095","model_system":"Rat methyl-demand feeding and hepatocyte experiments; reaction context from the primary report","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [creatine-p11595668] Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate. 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