3.4.21.27	activated factor IX	autoactivation, cleavage of FXI at the Arg369-Ile370 bond. activated factor IX is part of a feedback loop that sustains thrombin generation through FIX activation to consolidate coagulation	707856	
3.4.21.27	activated factor VII	-	707308	
3.4.21.27	activated factor XI	-	709721	
3.4.21.27	activated factor XII	activated factor XII-mediated activation of FXI appears to play a central role in formation of pathologic thrombi in murine thrombosis models	707856	
3.4.21.27	activated factor XII	activates its substrate FXI	709722	
3.4.21.27	activated factor XII	cleaves FXI at the Arg369-Ile370 bond	707856	
3.4.21.27	activated factor XII	FXI activation proceeds through an intermediate with only one activated submit	709721	
3.4.21.27	alpha-thrombin	cleaves FXI at the Arg369-Ile370 bond	707856	
3.4.21.27	desmopressin	-	707308	
3.4.21.27	desmopressin	increase of both FXI activity (up to 31%) and antigen levels 60 min after infusion. Also contradictory results with a lack of rise of FXI levels after infusion	707148	
3.4.21.27	Dextran sulfate	33nM	667620	
3.4.21.27	Factor XII	-	718045	
3.4.21.27	Factor XII	FXI is activated by factor XII during ischemia reperfusion injury and within the growing thrombus according to the classical intrinsic pathway cascade	709722	
3.4.21.27	factor XIIa	-	717420, 718042, 731773, 732936, 753068	
3.4.21.27	factor XIIa	using a 10:1 molar ratio of FXI to FXIIa at 37°C	717844	
3.4.21.27	FXIa	-	669420	
3.4.21.27	FXIIa	-	667620, 669420	
3.4.21.27	kininogen	-	36529	
3.4.21.27	meizothrombin	cleaves FXI at the Arg369-Ile370 bond	707856	
3.4.21.27	additional information	activation of factor XI by thrombin and autoactivation to factor XIa	36539	
3.4.21.27	additional information	antibody 14E11 exerts an inhibitory effect on fXI activation, but not fXIa activity	717420	
3.4.21.27	additional information	FXI monomers are activated poorly, dimeric form is needed for activation. As FXI lacks a Gla domain, the dimeric structure may represent an alternative solution to the problem of tethering a prothrombotic molecule to a cellular surface in flowing blood in the vicinity of a wound	709721	
3.4.21.27	additional information	in blood challenged with low concentrations of tissue factor, factor XI can be activated independently of factor XII	718045	
3.4.21.27	additional information	platelets may play a role in FXI activation. FXI binding to platelets is not enhanced by kininogen	707856	
3.4.21.27	additional information	thrombin-mediated feedback activation	683756	
3.4.21.27	Protein disulfide isomerase	reduction of the enzyme by protein disulfide isomerase enhances its cleavage activity	754516	
3.4.21.27	thrombin	-	669420, 709722, 753068, 753069	
3.4.21.27	thrombin	1nM, activating function only in presence of dextran sulfate	667620	
3.4.21.27	thrombin	activated factor V is a cofactor for the activation of factor XI by thrombin. Depletion of factor V, or the addition of activated protein C, decreases the activation of the intrinsic pathway by thrombin in plasma. Factor XI binds to factor V with multiple binding sites. Addition of FVIIIa, kininogen, or protein S does not influence the formation of activated factor XI	710438	
3.4.21.27	thrombin	activates fXI	691466	
3.4.21.27	thrombin	activates FXI. FXI activation by thrombin is enhanced by charged substances, such as dextran sulfate or heparin. Thrombin binds to the A1 domain of FXI, with residues Glu66, Lys83, and Gln84 forming part of the binding site. The dimer is required for optimal FXI activation by thrombin	707856	
3.4.21.27	thrombin	FXI activation proceeds through an intermediate with only one activated submit	709721	
3.4.21.27	thrombin	the enzyme can be activated, albeit slowly, by thrombin	731773	
3.4.21.27	thrombin	thrombin generated early in coagulation by the tissue factor pathway activates FXI creating a positive feedback loop that sustains coagulation following inactivation of the factor VIIa/tissue factor complex by tissue factor pathway inhibitor	709722