Figure 2: Electrophoretograms of the synthesis and assembly processes of interlocked DNA nanostructures.

(a) Electrophoretogram of 1 pmol interlocked architecture and each components in 6% native polyacrylamide gel electrophoresis at pH 8. (1) M circle; (2) L and R circles; (3) raw product; (4) pure product. The new band in lane 3 with the slowest mobility corresponds to the formed [3]pseudocatenane. (b) Electrophoretogram of 1 pmol assembled [3]catenane in 2.5% agarose gel at pH 8. (1) [3]pseudocatenane; (2) [3]pseudocatenane plus 10 equivalent of ROs. The shift in the mobility of bands originates from the freely moving circles of the [3]catenane (lane 2 versus lane 1). (c–e) Electrophoretograms of 1 pmol interlocked DNA nanostructures (50 nM, 6% native polyacrylamide gels). (c) (1) [3]pseudocatenane at pH 8; (2) 1 plus 10 equivalent of ROs; (3) 2 plus 20 equivalent of cROs. An opposite shift in the mobility of bands is observed. (d) (1) [3]pseudocatenane plus H⁺; (2) [3]pseudocatenane plus ROs and H⁺; (3) 2 plus cROs. The two close bands in lane 2 correspond to [3]catenane before and after the cyclization of heads. (e) (1) Lane 2 in panel d plus OH⁻ (2) lane 2 in panel d plus cROs and OH⁻. The addition of OH^- results in a disappearance of the slowest band (lane 1), indicating the disruption of i-motif structure at pH 8.