The interaction of human blood coagulation factor VII and tissue factor: the effect of anti factor VII, anti tissue factor and diisopropylfluorophosphate.

The effect of Factor VII antibody and an antibody to the apoprotein of tissue factor has been tested on the product formed between Factor VII, tissue factor and calcium ions. The antibody to the apoprotein of tissue factor neutralized tissue factor but had no effect on the extrinsic Factor X activator activity when Factor VII had been allowed to react with tissue factor before the addition of the antibody. The Factor VII antibody neutralized Factor VII and it also blocked the Factor X activator activity when Factor VII had been incubated with tissue factor and calcium ions prior to the addition of Factor VII antibody.Diisopropylfluorophosphate (DFP) was found to neutralize native purified Factor VII and Factor VII in human plasma. This inhibition of Factor VII was very slow and required high concentrations of DFP. However, when the Factor VII had been preincubated with tissue factor and calcium ions, the neutralization of Factor VII by DFP occurred rapidly, and at much lower concentration of DFP.