FIGURE 2.

Expression and quantification of IL-31 mutants. Cos-7 cells were transfected with the empty pcDNA3.1 plasmid (control plasmid) or with the pcDNA3.1 plasmid encoding the V5 His-tagged wt (W.T.) or mutant IL-31. A, Western blot (WB) was performed on Cos-7 cells supernatants. An anti-V5 antibody was used for the revelation. B, concentrations of wt and mutant IL-31 were determined by ELISA as described under “Experimental Procedures.” C, purified proteins were analyzed by SDS-PAGE and silver staining revelation.