Fig 3. Effect of mutations in the lipid binding residues of TF on its decryption.

THP-1 cells transduced to express wild-type TF or TF mutants (1 x10⁶ cells/ml) were treated with a control vehicle, calcium ionomycin (10 μM for 10 min) or HgCl₂ (100 μM for 5 min). Then, FVIIa (10 nM) and FX (175 nM) were added to the cells, and the rate of FX activation was measured as described in the Methods. In a parallel experiment, THP-1 cells from the same batch that were used for FX activation studies were incubated with ¹²⁵I-labeled TF mAb 9C3 for 2 h at 4°C to measure TF protein expression levels on the cell surface. The data obtained in these two assays were used to calculate the specific activity of the wild-type and mutant TF. The data shown in the figure represents the mean ± SEM from 3 to 6 independent experiments performed in duplicate.