Figure 1.

A conformational and interactional overview of aptamers and their receptors. (A) The sequential conformation (left) and secondary structure (right) of the commercialized aptamer product Macugen. (B) Schematic illustrations (left) and molecular models (right) of the quadruplex DNA for the aptamer AS1411. (C) The overall structure of the RNA aptamer C13 and its receptor, G protein-coupled receptor kinase 2 (GRK2). C13 positions an adenine nucleotide in the ATP-binding pocket of GRK2 (shown as yellow and burgundy ribbons), which stabilizes GRK2 in a unique and remodeled conformation. The terminal stem of the aptamer indirectly contributes to its affinity. Adapted from ¹⁸, ²⁹.