Figure 2.

Aptamers Predicted Secondary Structures and Binding to α5-Expressing Cells

(A) Predicted secondary structure of aptamers H02, G11, B03, G10, and H03. Structures were predicted using the mfold web server.⁶⁷ Nucleotides 1−19 and 50−68 correspond to fixed flanks of the candidate sequences. They are shown in dark red. ΔG values are noted above the structures. (B and C) Monitoring of the binding of five Cy5-labeled aptamers (H02, G11, B03, G10, and H03) at 5 μM on CHO-B2 and U87MG cell lines at 4°C using confocal microscopy. Nuclei, counterstained with Hoechst, are shown in royal blue. Aptamers, coupled to Cy5, are shown in white. (B) Binding on CHO-B2 α5+. α5 integrin is visualized, using the GFP-fused protein, in green. (C) Binding on U87MG α5+. α5 integrin was labeled with the IIA1 antibody and is shown in green. Images were captured at the same setting to allow direct comparison of staining patterns.