Enantioselective recognition mechanism of ofloxacin via Cu(II)-modulated DNA

J Phys Chem B. 2014 May 22;118(20):5300-9. doi: 10.1021/jp412460y. Epub 2014 May 13.

Abstract

The specific interactions of Cu(2+) with self-complementary DNA sequences involving d[G4C4(GC)2G4C4], d[(GC)10], and d[(AT)10], as well as the chiral recognition mechanism of ofloxacin enantiomers via the Cu(II)-modulated DNAs, were investigated using characterizations of circular dichroism, gel electrophoresis, FT-IR spectroscopy, UV melting measurement, electron paramagnetic resonance, and HPLC. The Cu(II)-coordinated GC-rich DNAs exhibit amplified enantioselectivity toward the S-enantiomer of ofloxacin. Especially in the case of d[G4C4(GC)2G4C4], ofloxacin enantiomers intercalate into the two adjacent guanine bases through the minor groove mediated by Cu(2+), which leads to a more favorable binding between S-ofloxacin and DNA. The highest ee value of ofloxacin enantiomers in the permeate after being adsorbed by the Cu(II)-DNA complex is obtained as 49.2% in the R-enantiomer at the [Cu(2+)]/[base] molar ratio of 0.25, while at the [Cu(2+)]/[base] molar ratio of 0.05 the highest ee value of ofloxacin enantiomers in the retentate reaches 26.3% in the S-enantiomer. This work illustrates a novel promising route to construct DNA-based chiral selectors toward certain drug enantiomers through the programmable enantioselective recognition on the basis of DNA chirality and the specific binding of transition metal ions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Base Sequence
  • Binding Sites
  • Circular Dichroism
  • Copper / chemistry*
  • DNA / chemistry*
  • DNA / metabolism
  • Electron Spin Resonance Spectroscopy
  • Molecular Dynamics Simulation
  • Nucleic Acid Conformation
  • Ofloxacin / chemistry*
  • Ofloxacin / metabolism
  • Oligonucleotides / chemistry
  • Oligonucleotides / metabolism
  • Spectroscopy, Fourier Transform Infrared
  • Stereoisomerism

Substances

  • Oligonucleotides
  • Copper
  • DNA
  • Ofloxacin