Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids.

Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the human beta-globin gene.

trans-5-aminopipecolyl-aegPNA chimera: design, synthesis, and study of binding preferences with DNA/RNA in duplex/triplex mode.

The design and synthesis of novel chiral PNA monomer based on trans-5-aminopipecolic acid is reported. The trans diequatorial disposition of the 1,4 ring substituents in six-membered 5-aminopipecolic acid derivative could be favorable over trans 1,3 axial-equatorial disposition in 4-aminopipecolic acid of PNA. Studies on the synthesis of trans-4/5-aminopipecolyl PNA-eagPNA chimeras and their binding preferences to DNA/RNA in duplex/triplex modes are described.

Chimeric (aeg-pyrrolidine)PNAs: synthesis and stereo-discriminative duplex binding with DNA/RNA.

The design and facile conversion of naturally occurring 4-hydroxyproline to all four diastereomers of thymine pyrrolidine PNA monomer, (2R,4S)-adenine, -guanine and -cytosine monomers and their incorporation into duplex forming PNA oligomers is reported. The interesting results of the hybridization studies with complementary DNA/RNA sequences in either parallel or antiparallel orientation reveal the stereochemistry-dependent DNA vs. RNA discriminations and parallel/antiparallel orientation selectivity.

Design and synthesis of conformationally frozen peptide nucleic acid backbone: chiral piperidine PNA as a hexitol nucleic acid surrogate.

The design and facile synthesis of novel chiral piperidine PNA from naturally occurring 4-hydroxy-L-proline is reported. The stereospecific ring-expansion reaction to get six-membered piperidine derivative from 5-membered pyrrolidine derivative is exploited for this synthesis. The resulting conformationally constrained PNA is utilized for the synthesis of PNA mixmers and the concept is substantiated by UV-Tm studies of the resulting PNA(2):DNA complexes.