engleski

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

A novel naphtalene diiimde analogue (NDI) equipped at imide positions with two guanidinio-carbonyl-pyrrole (GCP) pedant arms interacted significantly stronger with ds-DNA at pH 5 than at pH 7, due to reversible protonation of GCP arms. This was consequence of pH-switchable threading intercalation into ds-DNAs only at pH 5, while at neutral conditions (pH 7) NDI-GCP2 switched to the DNA minor groove binding. Intriguingly, NDI-GCP2 was at both pH bound to ds-RNA major groove, still showing higher affinity and thermal denaturation effect at pH 5 due to GCP protonation. At excess over DNA/RNA conjugate NDI-GCP2 showed also aggregation along ds-polynucleotide and AFM and DLS demonstrated that NDI-GCP2 has pronounced ds-DNA condensation ability.

DNA/RNA recognition ; Naphthalene diimide ; guanidinio-carbonyl-pyrrole ; fluorescence ; circular dichroism ; AFM

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