Internalization and recycling of TF.

Monolayers of BHK(TF) cells were allowed to internalize VIIa (▪) or FFR-VIIa (▴) for various times, from 15 minutes to 4 hours. The cell surface–associated VIIa or FFR-VIIa was subsequently removed by low-pH buffer wash, and the exposure of TF on the cell surface was measured by either ¹²⁵I-VIIa binding (A) or the cell surface–associated TF/VIIa functional activity (B) as described in “Materials and methods.” Data are the mean ± SD of 3 independent experiments in triplicate.