Найдено научных статей и публикаций: 1, для научной тематики: PNA
1.
4. Watson R.M., Skorik Y.A., Patra G.K., Achim C.
- Journal of American Chemical Society , 2005
Recent studies on metal incorporation in ligand-modified nucleic acids have focused on the effect
of metal coordination on the stability of metal-containing duplexes or triplexes and on the metal binding
selectivity but did not address the effect of the sequence of the nucleic acid in which the liga...
Recent studies on metal incorporation in ligand-modified nucleic acids have focused on the effect
of metal coordination on the stability of metal-containing duplexes or triplexes and on the metal binding
selectivity but did not address the effect of the sequence of the nucleic acid in which the ligands are
incorporated. We have introduced 8-hydroxyquinoline Q in 10-mer PNA strands with various sequences
and have investigated the properties of the duplexes formed from these strands upon binding of Cu2+.
Variable-temperature UV-vis spectroscopy shows that, in the presence of Cu2+, duplexes are formed even
from ligand-modified Q-PNA strands that have a large number of mismatches. Spectrophotometric titrations
demonstrate that at any temperature, one Cu2+ ion binds a pair of Q-PNA strands that each contain one
8-hydroxyquinoline, but below the melting temperature, the PNA duplex exerts a supramolecular chelate
effect, which prevents the transformation in the presence of excess Cu2+ of the 1:2 Cu2+:Q-PNA complexes
into 1:1 complexes. EPR spectroscopy gives further support for the existence in the duplexes of [CuQ2]
moieties that are similar to the corresponding square planar synthetic complex formed between Cu2+ and
8-hydroxyquinoline. As PNA duplexes show a preferred handedness due to the chiral induction effect of a
C-terminal L-lysine, which is transmitted through stacking interactions within the duplex, only if the metalcontaining
duplex has complementary strands, does it show a chiral excess measured by CD spectroscopy.
The strong effect of the metal-ligand moiety is suggestive of an increased correlation length in PNA duplexes
that contain such moieties. These results indicate that strong metal-ligand alternative base pairs significantly
diminish the importance of Watson-Crick base pairing for the formation of a stable PNA duplex and lead
to high mismatch tolerance, a principle that can be used in the construction of hybrid inorganic-nucleic
acid nanostructures.
Journal of American Chemical Society. 2005 127(42) 14628-14639