FIG. 5.

Comparison of ³H-labeled Ad binding to MDA-MB-453, SCC-4, SKOV3.ip1, and A-431 cells. ³H-labeled Ad was preincubated for 30 min at room temperature with different amounts of sCAR-His₆ or sCAR-EGF. ³H-Ad/sCAR-ligand mixtures (10⁵ cpm per sample) were then added to cells aliquots (10⁶) and allowed to bind for 1 h at 4°C. Bound radioactivity was determined after pelleting the cells by centrifugation. Binding indices were calculated from the ratio of the mean bound radioactivity of ³H-Ad preincubated in presence of sCAR-ligand versus ³H-Ad preincubated in absence of sCAR-ligand protein. Each point represents the cumulative mean ± SD of triplicate determinations. Some error bars depicting SDs are smaller than the symbols.