FIGURE 4.
Analysis of selected hEGFR binders. Sequences obtained after hEGFR selection are shown for libraries rcSso7d-11 (top) and rcSso7d-18 (bottom). For each library, the nine randomized positions of sequence families are highlighted with one color. Framework mutations are shown in magenta. B, A431 cells were titrated with His6-SUMO-rcSso7d mutants, and binding was detected with anti-His-Alexa Fluor 647 (error bars represent S.D. of three independent experiments). The lines show the fits to a 1:1 binding model with Kd values shown in A. C, A431 cells were preincubated with 1.5 μm rcSso7d mutants without His tags or with 300 nm cetuximab (Cetux.) (blocking reagent) followed by addition of 20 nm His6-SUMO-rcSso7d mutants (detection reagent) and detection with an anti-His antibody. Average blocking levels of two independent experiments are shown. MFI, mean fluorescence intensity.