Figure 5.

Pull-down of biotinylated targets from spiked HeLa cell lysate by affinity-matured monobodies. Four biotinylated targets were mixed (1 pmol each) with HeLa cell lysate (10 µg). FLAG-tagged FN3 monobodies were added to the mixture, and subsequent target/monobody complex was pulled down via anti-FLAG antibody-coated paramagnetic beads. After washing, the target/monobody complex was eluted off the beads and used in Western blot. Biotinylated targets were detected via a streptavidin-infrared dye conjugate. Red arrows indicate the positions of two pull-downed targets on the blot.