Effect of receptor-associated protein, heparin, and tissue factor pathway inhibitor/factor Xa on tissue factor–specific binding and internalization of coagulation factor VIIa
| . | Cell surface–associated VIIa, % of control . | Internalized VIIa, % of control . |
|---|---|---|
| RAP | 104 ± 5 | 102 ± 2 |
| Heparin | 96 ± 5 | 106 ± 12 |
| TFPI/Xa | 112 ± 8 | 105 ± 7 |
| . | Cell surface–associated VIIa, % of control . | Internalized VIIa, % of control . |
|---|---|---|
| RAP | 104 ± 5 | 102 ± 2 |
| Heparin | 96 ± 5 | 106 ± 12 |
| TFPI/Xa | 112 ± 8 | 105 ± 7 |
Confluent monolayers of BHK(TF) cells were incubated with 10 nM125I-VIIa for 1 hour in the absence or presence of 100 nM RAP, 1 U/mL heparin, or 10 nM TFPI/Xa. Complexes of TFPI/Xa were prepared by incubating equimolar amounts of recombinant full-length TFPI and Xa for 30 minutes at 37°C. Data obtained with the cells in the absence of TFPI/Xa, heparin, or RAP were set to 100%. Data are the mean ± SD of 3 independent experiments in triplicate.
VIIa indicates coagulation factor VIIa; RAP, receptor-associated protein; TFPI/Xa, tissue factor pathway inhibitor/factor Xa; BHK(TF), baby hamster kidney stably transfected with full-length tissue factor.