A Carbazole-Derived Nitroxide That Is an Analogue of Cytidine: A Rigid Spin Label for DNA and RNA.

Anna-Lena Johanna Segler, Snorri Th Sigurdsson

The Journal of organic chemistry 2021 Sep 03

filter terms:

A variety of semirigid and rigid spin labels comprise a valuable arsenal for measurements of biomolecular structures and dynamics by electron paramagnetic resonance (EPR) spectroscopy. Here, we report the synthesis and characterization of rigid spin labels Ċ and Ċm for DNA and RNA, respectively, that are carbazole-derived nitroxides and analogues of cytidine. Ċ and Ċm were converted to their phosphoramidites and used for their incorporation into oligonucleotides by solid-phase synthesis. Analysis of Ċ and Ċm by single-crystal X-ray crystallography verified their identity and showed little deviation from planarity of the nucleobase. Analysis of the continuous-wave (CW) EPR spectra of the spin-labeled DNA and RNA duplexes confirmed their incorporation into the nucleic acids and the line-shape was characteristic of rigid spin labels. Circular dichroism (CD) and thermal denaturation studies of the Ċ-labeled DNAs and Ċm-labeled RNAs indicated that the labels are nonperturbing of duplex structure.

Citation

Anna-Lena Johanna Segler, Snorri Th Sigurdsson. A Carbazole-Derived Nitroxide That Is an Analogue of Cytidine: A Rigid Spin Label for DNA and RNA. The Journal of organic chemistry. 2021 Sep 03;86(17):11647-11659