Factor XI binds to high affinity sites on the surface of stimulated platelets where it is efficiently
activated by thrombin. Here, we provide evidence that the factor XI binding site on platelets …

Kallikrein (PKa), generated by activation of its precursor prekallikrein (PK), plays a role in the
contact activation phase of coagulation and functions in the kallikrein-kinin system to …

The presence of Factor XIII subunit a was demonstrated in human monocytes by
immunoperoxidase staining using specific antisera against Factor XIII and its subunits. This …

Human coagulation factor XI (FXI) is a plasma serine protease composed of 2 identical 80-
kd polypeptides connected by a disulfide bond. This dimeric structure is unique among …

Previous studies have suggested that human platelets can promote the activation of factor XI
by two different mechanisms, one requiring factor XII and ADP-treated platelets and the …

Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the
serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this …

The potentially active A subunit of factor XIII of blood coagulation has also been detected in
platelets and monocytes/macrophages though the exact function of this cellular …

Thrombin-catalyzed release of activation peptide (AP) from plasma factor XIII was studied to
characterize the regulation of this initial step in the activation of factor XIII zymogen (fibrin …

Abstract Factor XIII (a)[FXIII (a)] stabilizes clots and increases resistance to fibrinolysis and
mechanical disruption. FXIIIa also mediates red blood cell (RBC) retention in contracting …

The prothrombinase complex converts prothrombin to α-thrombin through the intermediate
meizothrombin (Mz-IIa). Both α-thrombin and Mz-IIa catalyze factor (F) XI activation to FXIa …