Kinetics of i-motif folding within the duplex context.

Non-canonical nucleic acid structures possess an ability to interact selectively with proteins, thereby exerting influence over various intracellular processes. Numerous studies indicate that genomic G-quadruplexes and i-motifs are involved in the regulation of transcription. These structures are formed temporarily during the unwinding of the DNA double helix; and their direct determination is a rather difficult task.

8-Oxoadenine: A «New» Player of the Oxidative Stress in Mammals?

Numerous studies have shown that oxidative modifications of guanine (7,8-dihydro-8-oxoguanine, 8-oxoG) can affect cellular functions. 7,8-Dihydro-8-oxoadenine (8-oxoA) is another abundant paradigmatic ambiguous nucleobase but findings reported on the mutagenicity of 8-oxoA in bacterial and eukaryotic cells are incomplete and contradictory. Although several genotoxic studies have demonstrated the mutagenic potential of 8-oxoA in eukaryotic cells, very little biochemical and bioinformatics data about the mechanism of 8-oxoA-induced mutagenesis are available.

Synthesis and Biological Evaluation of Benzo [4,5]- and Naphtho[2',1':4,5]imidazo[1,2-c]pyrimidinone Derivatives.

Azacarbazoles have attracted significant interest due to their valuable properties, such as anti-pathogenic and antitumor activity. In this study, a series of structurally related tricyclic benzo[4,5]- and tertacyclic naphtho[2',1':4,5]imidazo[1,2-c]pyrimidinone derivatives with one or two positively charged tethers were synthesized and evaluated for anti-proliferative activity. Lead tetracyclic derivative with two amino-bearing arms inhibited the metabolic activity of A549 lung adenocarcinoma cells with a CC value of 3.

Unwinding the SARS-CoV-2 Ribosomal Frameshifting Pseudoknot with LNA and G-Clamp-Modified Phosphorothioate Oligonucleotides Inhibits Viral Replication.

Ribosomal frameshifting (RFS) at the slippery site of SARS-CoV-2 RNA is essential for the biosynthesis of the viral replication machinery. It requires the formation of a pseudoknot (PK) structure near the slippery site and can be inhibited by PK-disrupting oligonucleotide-based antivirals. We obtained and compared three types of such antiviral candidates, namely locked nucleic acids (LNA), LNA-DNA gapmers, and G-clamp-containing phosphorothioates (CPSs) complementary to PK stems.