TFPI – Tissue Factor Pathway Inhibitor Antibody

Affinity Biologicals, Inc. manufactures a TFPI – Tissue Factor Pathway Inhibitor Antibody which can be found in the listing below.  Further information about our TFPI – Tissue Factor Pathway Inhibitor Antibody is available by following the links below.  Our TFPI – Tissue Factor Pathway Inhibitor Antibody’s immunogen is prepared from synthetic peptide corresponding to NH-terminus of human TFPI conjugated to carrier and specific for TFPI as demonstrated by immunoelectrophoresis and ELISA.  Antibodies are manufactured for use in research applications.

Listing of TFPI – Tissue Factor Pathway Inhibitor Antibody

Description of TFPI – Tissue Factor Pathway Inhibitor

TFPI circulates in human plasma as complexes with LDL, HDL and VLDL¹ and can be found in several forms: a 36,000 D molecule, a 43,000 D molecule and as truncated moieties. This heterogeneity of size appears, in part, to be the result of the formation of mixed disulfide complexes between TFPI and apolipoprotein AII.² In humans, approximately 10% of total TFPI is carried by platelets which release TFPI once they are activated by thrombin.³ Thus, at the site of a wound, where platelets aggregate, elevated levels of TFPI are present. Based on the initial isolation of the inhibitor it was found that TFPI inhibits Tissue Factor (TF) procoagulant activity; i.e., the TF/FVIIa complex, and directly inhibits factor Xa by binding at or near its serine active site.5 The inhibitory mechanism of TFPI is a two step process. In the first step TFPI binds to factor Xa via its Kunitz-2 domain, followed by a second step in which the TFPI/FXa complex binds to the TF/FVIIa complex via its Kunitz-1 domain, forming an inactive quaternary TFPI/FXa/TF/FVIIa complex. The direct inhibition of factor Xa is based on a 1:1 stoichiometry and is not calcium dependent.4  Furthermore, factor Xa inhibition does not solely rely on TFPI binding through Kunitz-2 domain. The C-terminal region of TFPI is required for a high affinity binding between TFPI and factor Xa and the subsequent factor X a inhibition.6  It has been found that TFPI is released into blood following administration of heparin and that heparin enhances TFPI inhibition of factor Xa, and that the C-terminal region is the major heparin binding site.7

References and Reveiws

  1. Hubbard, A. R. and Jennings, C. A. Thrombosis Research 1987, 46: 527-537.
  2. Novotny, W. F., Girard, T. and Miletich, J. P. Journal of Biological Chemistry 1989, 264: 18832-18837.
  3. Novotny, W. F., Girard, T. J. and Miletich, J. P. Blood 1988, 72: 2020-2025.
  4. Broze, G. J. and Miletich, J.P. Proceedings of the National Academy of Science USA 1987, 84: 1886-1890.
  5. Broze, G. J., Warren, L. A., Novotny, W. F., Higuchi, D. A., Girard, J. J. and Miletich, J. P. Blood 1988, 71: 335-343.
  6. Wesselschmidt, R. L, Likert, K., Girard, T., Wun, T. and Broze, Jr, G. J. Blood 1992, 79: 2004-2010.
  7. Lindahl, A. K., Sandset, P. M. and Abilgaard, U. Blood Coagulation and Fibrinolysis 1992; 3: 439-449.