The A1 and A2 Subunits of Factor VIIIa Synergistically Stimulate Factor IXa Catalytic Activity [PDF]
Journal of Biological Chemistry, 1999 Factor VIIIa, the protein cofactor for factor IXa, is comprised of A1, A2, and A3-C1-C2 subunits. Recently, we showed that isolated A2 subunit enhanced the k cat for factor IXa-catalyzed activation of factor X by ∼100-fold (∼1 min−1), whereas isolated A1
Philip J. Fay +2 more
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The A2 Subunit of Factor VIIIa Modulates the Active Site of Factor IXa [PDF]
Journal of Biological Chemistry, 1998 Factor VIIIa, the protein cofactor for factor IXa, is comprised of A1, A2, and A3-C1-C2 subunits. Isolated subunits of factor VIIIa were examined for their ability to accelerate the factor IXa-catalyzed activation of factor X. The A2 subunit enhanced the
Philip J. Fay, Kyoko Koshibu
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Factor VIIIa-mimetic cofactor activity of a bispecific antibody to factors IX/IXa and X/Xa, emicizumab, depends on its ability to bridge the antigens. [PDF]
Thromb Haemost, 2017 Summary Emicizumab, a humanised bispecific antibody recognising factors (F) IX/IXa and X/Xa, can accelerate FIXa-catalysed FX activation by bridging FIXa and FX in a manner similar to FVIIIa.
Kitazawa T +11 more
europepmc +2 more sources
Mechanisms of Factor Xa-catalyzed Cleavage of the Factor VIIIa A1 Subunit Resulting in Cofactor Inactivation [PDF]
Journal of Biological Chemistry, 2003 Activation of factor VIII by factor Xa is followed by proteolytic inactivation resulting from cleavage within the A1 subunit (residues 1–372) of factor VIIIa.
Keiji Nogami +2 more
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Exosite-dependent regulation of factor VIIIa by activated protein C [PDF]
Blood, 2003 AbstractActivated protein C (APC) is a natural anticoagulant serine protease in plasma that down-regulates the coagulation cascade by degrading cofactors Va and VIIIa by limited proteolysis. Recent results have indicated that basic residues of 2 surface loops known as the 39-loop (Lys37-Lys39) and the Ca2+-binding 70-80–loop (Arg74 and Arg75) are ...
Chandrashekhara Manithody +2 more
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Combining mutations that modulate inter-subunit interactions and proteolytic inactivation enhance the stability of factor VIIIa. [PDF]
Thromb Haemost, 2014 Wakabayashi H, Wintermute JM, Fay PJ.
europepmc +6 more sources
Factor IXa:Factor VIIIa Interaction [PDF]
Journal of Biological Chemistry, 2001 The physiologic activator of factor X consists of a complex of factor IXa, factor VIIIa, Ca2+ and a suitable phospholipid surface. In one study, helix 330 (162 in chymotrypsin) of the protease domain of factor IXa was implicated in binding to factor ...
S. P. Bajaj +6 more
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The Connecting Segment between Both Epidermal Growth Factor-like Domains in Blood Coagulation Factor IX Contributes to Stimulation by Factor VIIIa and Its Isolated A2 Domain [PDF]
Journal of Biological Chemistry, 2002 The light chain of activated factor IX comprises multiple interactions between both epidermal growth factor-like domains that contribute to enzymatic activity and binding of factor IXa to its cofactor factor VIIIa.
Patrick H. N. Celie +5 more
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The Factor VIIIa C2 Domain (Residues 2228–2240) Interacts with the Factor IXa Gla Domain in the Factor Xase Complex [PDF]
Journal of Biological Chemistry, 2008 Factor VIIIa functions as a cofactor for factor IXa in the phospholipid surface-dependent activation of factor X. Both the C2 domain of factor VIIIa and the Gla domain of factor IXa are involved in phospholipid binding and are required for the activation
Tetsuhiro Soeda +7 more
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Platelets stabilize factor VIIIa against loss of activity through subunit dissociation [PDF]
BloodActivated platelets have binding sites for factor VIII (FVIII) that include soluble fibrin bound to the αIIbβ3 integrin (Phillips et al 2004. J Thromb Haemost; Gilbert et al 2015. Blood).
Valerie A. Novakovic +3 more
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