FIGURE 3.

Aptamers bind to cellular BACE1. (A) SPR profile of GST-BACE cytoplasmic tail binding to immobilized S10 aptamer (black curve) and nonbinding GST-control protein (light gray). (B) (Top panel) Pull-down of GST-B1-CT with biotinylated RNA aptamers (S10, K11, cy0: unselected pool, no RNA); (bottom panel) pull-down of cellular BACE1 from HEK269 lysate with biotinylated RNAs (S10, cy0: unselected pool, no RNA) coupled to streptavidine coated magnetic beads. Measurements were done in duplicates. (C) Binding of [³²P]-labeled RNA to cellular BACE. BACE1 from HEK269 cells is immunoprecipitated with an antibody against the N-terminal domain of BACE1 and coupled to Protein-A agarose. Bars indicate the relative amounts of aptamer (S10) or unselected pool RNA (cy0) bound to Protein A agarose derivatized with cellular full-length BACE (+), underivatized Protein A agarose (neg), or antibody-derivatized Protein A agarose (AK).