Water-soluble clickable nucleic acid (CNA) polymer synthesis by functionalizing the pendant hydroxyl

Water-soluble single stranded DNA analogs are generated via thiol–ene photo-oligomerization.

Acyclic analogs of nucleosides based on tris(hydroxymethyl)phosphine oxide: synthesis and incorporation into short DNA oligomers

Tris-(hydroxymethyl)phosphine oxide (THPO) to a certain extent resembles a part of 2′-deoxyribofuranose, although it exists in an acyclic form only and the oxygen atom at the THPO phosphorus center provides additional hydration site or acceptor of hydrogen bonds. After proper protection of hydroxyl groups, THPO was functionalized with nucleobases and converted into phosphoramidite monomers suitable for incorporation into growing oligonucleotide chains within the solid phase synthesis protocol. The resultant THPO-DNA analogs show reduced affinity to complementary DNA strands, and are resistant towards snake venom and calf spleen exonucleases.

Intracellular Localization of PNA in Human Cells upon its Introduction by Electroporation

Peptide nucleic acid (PNA) is one of the most useful DNA analogs in a wide variety of gene analysis in human cells. In order to exhibit its maximal functions, PNA must be localized to a desired place (e.g., nucleus, cytoplasm and other organelles). Here, we introduced PNAs into HeLa cells by electroporation and examined their localization at various time points. The PNA which binds to the mitochondrial COII gene was initially accumulated in the nucleus, and thereafter mostly transferred to cytoplasm. This time-dependent intracellular localization of PNA is ascribed to the breakdown of the nuclear envelope in the cell division. On the other hand, another PNA that binds to telomere repeat sequence mostly remained in the nucleus, even after the cell division occurred. The retention of this PNA in the nucleus was further enhanced when it was conjugated with Cy3.