Inhibition of PNA triplex formation by N4-benzoylated cytosine.
AUTOR(ES)
Christensen, L
RESUMO
The synthesis of N-((N4-(benzoyl)cytosine-1-yl)acetyl)- N -(2-Boc-aminoethyl)glycine (CBz) and the incorporation of this monomer into PNA oligomers are described. A single CBzresidue within a 10mer homopyrimidine PNA is capable of switching the preferred binding mode from a parallel to an antiparallel orientation when targeting a deoxyribonucleotide sequence at neutral pH. The resulting complex has a thermal stability equal to that of the corresponding PNA-DNA duplex, indicative of a strong destabilization of Hoogsteen strand PNA binding due to steric interference by the benzoyl moieties. Accordingly, incorporation of the CBz residue into linked PNAs (bis-PNAs) results in greatly reduced thermal stability of the formed PNA:DNA complexes. Thus, incorporation of the CBz monomer could eliminate the stability bias of triplex-forming sequences in PNA used in hybridization arrays and combinatorial library formats. Furthermore, it is shown that the benzoyl moiety does not severely interfere with Watson-Crick hydrogen bonding, thereby presenting an interesting route for novel cytosine modifications.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=147602Documentos Relacionados
- Guanine tetraplex formation by short DNA fragments containing runs of guanine and cytosine.
- Transfer RNA structure by carbon NMR: C2 of adenine, uracil and cytosine.
- Positively charged oligonucleotides overcome potassium-mediated inhibition of triplex DNA formation.
- A new approach to overcome potassium-mediated inhibition of triplex formation.
- Triplex formation at physiological pH by 5-Me-dC-N4-(spermine) [X] oligodeoxynucleotides: non protonation of N3 in X of X*G:C triad and effect of base mismatch/ionic strength on triplex stabilities.
