FIGURE 5.

EGFR-dependent anti-proliferative activity of IFNα-2a-EGF chimeric proteins. Daudi and Daudi-EGFR cells were grown for 60 h in the presence of various concentrations of IFNα-2a-EGF chimeric proteins or the corresponding IFNα-2a proteins purified from Pichia. The relative number of viable cells was determined by the production of formazan, which absorbs at A₄₆₀, from tetrazolium (see “Experimental Procedures”). Curves were fit to the data using a four-parameter fit (Microcal Origin 5.0).