Figure 4
αHGA targets gp160 for degradation more rapidly than GPG-NH 2 . (A) HeLa-tat III cells were transfected to express gp160 and treated with 20 μM (upper panel) or 100 μM GPG-NH2 (lower panel) for the indicated times pre- or post-transfection. The cells were harvested 24 h post transfection and immunoblotted with mAb towards gp41. (B) Densitometric measurements of gp160 and degradation products in samples treated with 20 μM (left panel) or 100 μM GPG-NH2 (right panel) as described in (A) and given as percentage of total gp160 in untreated cells in (A), lane 1. (C) As in (A), except the cells were treated with αHGA at 20 μM (upper panel) or 100 μM (lower panel). (D) Densitometric measurements as described in (B) of samples treated with αHGA at 20 μM (left panel) or 100 μM (right panel) described in (C). (E) Glycoprotein blot of HeLa-tat III cell lysates collected from cells treated with the indicated concentrations of αHGA for 24 h and stained for total protein and subsequently probed with the lectin Concanavalin A. The asterisks highlight the decreased molecular mass species.