engleski

Small molecule probes finely differentiate between various ds- and ss-DNA and RNA by fluorescence, CD and NMR response

Two small molecules showed intriguing properties of analytical multipurpose probes, whereby one chromophore gives different signal for many different DNA/RNA by application of several highly sensitive spectroscopic methods. Dyes revealed pronounced fluorescence ratiomeric differentiation between ds-AU-RNA, AT-DNA and GC-DNA in approximate order 10:8:1. Moreover, the dyes showed specific fluorimetric response for poly rA among other ss-RNA. In parallel, the dyes showed specific chiral recognition of poly rU in respect to the other ss-RNA by induced CD (ICD) pattern, which was attributed to the dye-side-chain contribution to binding (confirmed by absence of any ICD band for reference compound lacking side-chain). Most intriguingly, minor difference in the side-chain attached to dye chromophore resulted in opposite sign of dye-ICD pattern, whereby differences in NMR NOESY contacts and proton chemical shifts between two dye/oligo rU complexes combined with MD simulations and CD calculations attributed observed bisignate ICD to the dimeric dye aggregate within oligo rU.

DNA/RNA recognition ; fluorescence ; induced circular dichroism ; chiral recognition ; molecular modelling

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