{"id":"488886a0-8b3c-562d-b4cc-db13733ed339","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:calcium-phospholipid-prothrombinase","predicate":"proteolytically_converted_to","statement":"Factor Xa activated bovine prothrombin efficiently when factor Va, Ca2+ and phosphatidylserine-containing phospholipids assembled the complete prothrombinase system.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"9b38c580-9968-5789-9143-3f7a33b7e60e","mechanism_event_label":"Calcium helps the membrane-associated clotting machinery generate thrombin.","subject":{"id":"7831d47f-191c-5515-8202-534bc962e1ad","slug":"f2","display_name":"Prothrombin / coagulation factor II / F2","entity_type_key":"protein"},"object":{"id":"42e4f9cc-6925-5c95-b4b4-4183ae58ba7a","slug":"f2-thrombin","display_name":"Thrombin (proteolytically activated F2)","entity_type_key":"protein_state"},"evidence_count":1,"mechanism_event":{"id":"9b38c580-9968-5789-9143-3f7a33b7e60e","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:calcium-phospholipid-prothrombinase-event","event_type":"biochemical_relationship","label":"Calcium helps the membrane-associated clotting machinery generate thrombin.","description":"Factor Xa activated bovine prothrombin efficiently when factor Va, Ca2+ and phosphatidylserine-containing phospholipids assembled the complete prothrombinase system.","status":"provisional","compartment":{"slug":"experimental-phospholipid-surface","display_name":"Experimental phospholipid surface"},"participants":[{"entity":{"id":"5f520bf3-606b-5c80-8a22-5069dd8d07e9","slug":"f10-activated","display_name":"Activated coagulation factor X (factor Xa)","entity_type_key":"protein_state"},"role":"protease","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"de471bf2-245d-5462-9844-14e715026c37","slug":"f5-activated","display_name":"Activated coagulation factor V (factor Va)","entity_type_key":"protein_state"},"role":"protein_cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"assembly_cofactor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"0e2dd859-6135-556e-938f-d177f1e8c1ad","slug":"phosphatidylserine","display_name":"Phosphatidylserine","entity_type_key":"lipid"},"role":"anionic_membrane_lipid","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"2f77ef6d-3ecd-5a80-9ca3-3cbea403d9fc","slug":"phosphatidylcholine","display_name":"Phosphatidylcholine","entity_type_key":"lipid"},"role":"assay_membrane_lipid","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"5d87fc7e-6f9e-5960-96c0-733eb3b522f7","slug":"prothrombinase-complex","display_name":"Membrane-associated prothrombinase complex","entity_type_key":"protein_complex"},"role":"catalytic_assembly","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""},{"entity":{"id":"7831d47f-191c-5515-8202-534bc962e1ad","slug":"f2","display_name":"Prothrombin / coagulation factor II / F2","entity_type_key":"protein"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":6,"notes":""},{"entity":{"id":"42e4f9cc-6925-5c95-b4b4-4183ae58ba7a","slug":"f2-thrombin","display_name":"Thrombin (proteolytically activated F2)","entity_type_key":"protein_state"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":7,"notes":""},{"entity":{"id":"db4e3191-7a11-56ed-bc34-3bbc17160c11","slug":"experimental-phospholipid-surface","display_name":"Experimental phospholipid surface","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":8,"notes":"Study location; presence here is not a separate transport or causal claim."}]},"contexts":[{"dimension":"compartment_description","value_text":"Phospholipid surface","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Kinetic reconstitution with defined phospholipids","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Low residual Xa activity exists without the complete complex; this establishes biochemical assistance, not that extra dietary calcium accelerates clotting.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Bos taurus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Calcium helps the membrane-associated clotting machinery generate thrombin.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[rosing1980] The role of phospholipids and factor Va in the prothrombinase complex (1980). https://pubmed.ncbi.nlm.nih.gov/7350159/ DOI: 10.1016/S0021-9258(19)86294-4","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified blood proteins","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"dca3b87d-8713-5516-ab94-0a51b4822b5b","evidence_kind":"source_excerpt","locator":"Lines 1116-1126","start_line":1116,"end_line":1126,"excerpt":"### calcium-phospholipid-prothrombinase\nFactor Xa activated bovine prothrombin efficiently when factor Va, Ca2+ and phosphatidylserine-containing phospholipids assembled the complete prothrombinase system.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Calcium helps the membrane-associated clotting machinery generate thrombin.\norganism: Bos taurus\ntissue_or_cell_type: Purified blood proteins\nexperimental_model: Kinetic reconstitution with defined phospholipids\nlimitations: Low residual Xa activity exists without the complete complex; this establishes biochemical assistance, not that extra dietary calcium accelerates clotting.\ncompartment_description: Phospholipid surface\n[rosing1980] The role of phospholipids and factor Va in the prothrombinase complex (1980). https://pubmed.ncbi.nlm.nih.gov/7350159/ DOI: 10.1016/S0021-9258(19)86294-4","model_system":"Kinetic reconstitution with defined phospholipids","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [rosing1980] The role of phospholipids and factor Va in the prothrombinase complex (1980). https://pubmed.ncbi.nlm.nih.gov/7350159/ DOI: 10.1016/S0021-9258(19)86294-4","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}