Figure 1.

The interactions of YOYO-1-labeled RNA aptamers 54 and 78 with DOPC or RAFT liposomes. (A) Emission spectra of aptamer bound YOYO-1 (excitation at 466 nm), titrated with DOPC liposomes (0 µM–1500 µM) (left) and RAFT liposomes (0 µM–1000 µM) (right). The fluorescence intensity of YOYO-1 decreases with the increase in liposome concentration, for both aptamers 54 (top chart) and aptamer 78 (bottom) indicating the energy transfer to the membrane-bound acceptor (Liss Rhod PE). RNA aptamer concentration 0.25 µM, YOYO concentration 2.5 µM. (B) Change of YOYO-1 fluorescence during titration of RNA aptamer 54 (top) and RNA aptamer 78 (bottom) with DOPC liposomes (left) or RAFT liposomes (right). F_max is the maximal YOYO-1 fluorescence obtained before acceptor-liposome titration. ΔF is the difference between measured fluorescence and F_max (C). Reciprocal of YOYO-1 fluorescence change during titration with DOPC (in left) or RAFT (right) liposomes. The calculated K_D values indicate stronger RNA aptamer interaction with RAFT liposomes. For RNA aptamer 54—membrane measurements (top), the K_D values are 168.4 µM and 66.2 µM with the interaction with DOPC and RAFT liposomes, respectively; for RNA aptamer 78, the K_D values are 530.0 µM and 188.5 µM for interaction with DOPC and RAFT liposomes, respectively. The regression line equation and the coefficient of determination (R²) are noted above the calculated K_D value in the top-right corner of the chart.