Figure 7

Immunoblot assay and epitope verification. Immunoblot assay was performed to verify the predicted epitope between PCSK9 and VHH-B11-Fc. PCSK9 and its deletants were loaded in the following sequence in groups of five samples (lanes 1–5 and 11–15: supernatants; lanes 6–10 and 16–20: cell precipitation lysate): PCSK9-Δ1 (383–405), PCSK9-Δ2 (429–449), PCSK9-Δ3 (153–449), PCSK9-Δ4 (450–692), and wild-type PCSK9 (red arrow). (A) The anti-HA Ab was used as primary Ab to check whether PCSK9 was expressed intracellularly (lanes 1–5) and extracellularly (lanes 6–10). The HRP-tagged goat anti-mouse IgG was used as the secondary antibody. (B) The B11-Fc Ab was used as a primary Ab to check whether PCSK9 and the deletants could still interact specifically with B11-Fc (lanes11–20). The HRP-tagged goat anti-human IgG was used as the secondary antibody.