Contrasting enantioselective DNA preference: chiral helical macrocyclic lanthanide complex binding to DNA

Area of Science:

• Coordination Chemistry
• Supramolecular Chemistry
• Biophysical Chemistry

Background:

• Chiral recognition is crucial in biological systems, with DNA conformation and chirality influencing life events.
• Small molecules targeting specific DNA structures can modulate gene function.
• Lanthanide complexes offer unique properties for molecular recognition.

Purpose of the Study:

• To synthesize and characterize chiral helical macrocyclic lanthanide(III) complexes.
• To investigate the enantioselective binding of these complexes to B-form DNA.
• To explore their differential effects on GC-rich and AT-rich DNA sequences.

Main Methods:

• Synthesis of chiral helical macrocyclic ytterbium(III) complexes.
• Enantioselective binding studies with B-form DNA.
• Analysis of DNA stabilization/destabilization using techniques like circular dichroism spectroscopy.

Main Results:

• The (M)- and (P)-enantiomers of Yb[L(SSSSSS/RRRRRR)](3+) selectively bind to B-DNA.
• The P-enantiomer stabilizes both poly(dG-dC)2 and poly(dA-dT)2.
• The M-enantiomer stabilizes poly(dA-dT)2 but destabilizes poly(dG-dC)2.
• Neither complex affects non-B-form or quadruplex DNA.

Conclusions:

• This study presents a novel example of chiral metal compounds with contrasting preferences for GC- and AT-DNA.
• These chiral complexes can selectively modulate DNA stability, potentially interfering with protein-DNA interactions.
• The findings provide insights for designing enantiomers that target specific DNA sequences and conformations for therapeutic applications.