Pathways of excess electron transfer in phenothiazine-tethered DNA containing single-base mismatches

Org Biomol Chem. 2009 May 21;7(10):2077-81. doi: 10.1039/b820311c. Epub 2009 Apr 8.


The effects of local structural disorder on excess electron transfer (EET) in DNA were investigated by evaluating photoinduced electron transfer in phenothiazine (PTZ)-modified oligodeoxynucleotides bearing single-base mismatches. Unexpectedly, more efficient electron transfer was observed for the mismatched duplexes than for the complementary DNA, suggesting that distraction of hydrogen bond interaction at the mismatch site enables electron injection or hopping beyond the mismatch sites. It was also anticipated that water accessibility of the mismatched nucleobases could affect EET because protonation of the electron-captured pyrimidine intermediates became competitive to EET, especially at the mismatch sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Pair Mismatch / genetics
  • Base Pair Mismatch / physiology*
  • Circular Dichroism
  • DNA / chemistry*
  • DNA / physiology
  • Electrochemistry
  • Electron Transport / physiology*
  • Electrons*
  • Kinetics
  • Nucleic Acid Conformation
  • Oligodeoxyribonucleotides / chemistry*
  • Oligodeoxyribonucleotides / metabolism
  • Phenothiazines / chemistry*
  • Pyrimidines / chemistry
  • Water / physiology


  • Oligodeoxyribonucleotides
  • Phenothiazines
  • Pyrimidines
  • Water
  • DNA
  • pyrimidine