Determination of the kinetic constants of tissue factor/factor VII/factor VIIA and antithrombin/heparin using surface plasmon resonance

Thromb Res. 1997 Feb 1;85(3):225-36. doi: 10.1016/s0049-3848(97)00007-8.

Abstract

Association of factor VIIa (FVIIa) with tissue factor (TF) is generally believed to be a critical step in the initiation of blood coagulation. In this study the rate constants for the complex formation and dissociation between FVII/FVIIa and TF were studied in real time using surface plasmon resonance, the BIAcore technique. Employing this technique ka and kd were determined and yielded a KD of 1 nM for FVII and 0.5 nM for FVII, respectively. The association and dissociation between antithrombin (AT) and the FVIIa/TF complex was also studied. In the presence of heparin, AT was bound to the FVIIa/TF complex in a dose-dependent manner with ka of 2 x 10(3) M-1 s-1. The binding of AT to FVIIa/TF increased the dissociation of FVIIa from TF about 20-fold.

MeSH terms

  • Antithrombin III / metabolism*
  • Binding Sites
  • Factor VII / metabolism*
  • Factor VIIa / metabolism*
  • Humans
  • Kinetics
  • Thrombin / metabolism*
  • Thromboplastin / metabolism*

Substances

  • Antithrombin III
  • Factor VII
  • Thromboplastin
  • Factor VIIa
  • Thrombin