| 초록 |
Emissive isomorphic nucleoside analogues are versatile tools for the investigation of DNA conformations due to their stable orientations within the structures. Furthermore, in contrast to conventional dyes, nucleoside analogues cause minimal disturbance to native DNA folding and interactions, allowing for a more accurate picture of their structures. Herein, we report the synthesis of a 19F-labeled fluorescent cytosine analogue, FPdC, and its incorporation into i-motif-forming DNA sequences. Compared to previously reported tricyclic cytosine derivatives, FPdC presented a four-fold improvement in brightness due to its high molar absorptivity and quantum yield. When incorporated into DNA and upon formation of i-motif structures, significant changes in fluorescence intensity and lifetime, as well as 19F NMR chemical shifts were observed. The changes in fluorescence intensity were highly reversible when the folding and unfolding of an i-motif structure was induced with Ag(I) and cysteine. |
