Selection of Single-Stranded DNA Molecular Recognition Elements against Exotoxin A Using a Novel Decoy-SELEX Method and Sensitive Detection of Exotoxin A in Human Serum

Figure 2

Structures of targets used in the Decoy-SELEX and SPR cross-binding assays. (a) Ribbon structure of the target of interest, Exotoxin A (PDB 1IKQ, 66 kDa) [8]. (b) Ribbon structure of streptavidin (PDB 4GJS, 60 kDa) used in cross bind assays [23]. ((c), (d)) Ribbon structures of bovine serum albumin (PDB 4F5S, 66.5 kDa) and Cholera toxin (PDB 2A5D, 84 kDa) used in negative rounds of selection and crossing binding assays [24, 25]. (e) Chemical structure of biotin used in negative rounds of selection and cross-binding assays.

(a) Exotoxin A

(b) Streptavidin

(c) Bovine serum albumin

(d) Cholera toxin

(e) Biotin