Figure 2

¹²⁵I-α ₂ M and ¹²⁵I-apoE-VLDL handling by GM00701 cells. GM00701 cells were incubated with ¹²⁵I-α₂M (1 μg/ml) at 4°C for 3 h (A) or at 37°C for 1 h (B) in the absence or presence of recombinant human RAP-GST (50 μg/ml) or unlabeled α₂M (10 μg/ml). (C) GM00701 and 3T3-L1 cells were incubated with ¹²⁵I-apoE-VLDL (2 μg/ml) supplemented with 3 μg/ml apoE at 4°C for 3 h in the absence (solid bars) or presence (shaded bars) of unlabeled apoE-VLDL (100 μg/ml). After the indicated incubation time, ¹²⁵I-ligand bound to cells at 4°C was quantitated by scintillation counting following extraction of cells with 0.1 M NaOH. ¹²⁵I-α₂M degradation was quantitated following TCA precipitation as described in Methods. Error bars represent standard deviations of triplicate points. Inset, purified VLDL was separated by 7.5% SDS-PAGE and proteins were stained with Coomassie R. Molecular mass markers shown at left are in kD.