A novel intramolecular G-quartet-containing fold of single-stranded d(GT)(8) and d(GT)(16) oligonucleotides

Biophys Chem. 2009 Aug;143(3):161-5. doi: 10.1016/j.bpc.2009.05.006. Epub 2009 May 20.

Abstract

Human genome is shown to be enriched with (GT)(n) stretches of lengths from 8 to 20 dinucleotides. Low temperature (T< or =10 degrees C) conformations of d(GT)(n) oligonucleotides (n=7, 8, 12, 16, 20) were studied by means of circular dichroism (CD), thermal melting, ethidium bromide (EtBr) probing and single nucleotide substitutions. Rotational relaxation times for EtBr:d(GT)(n) complexes confirmed a monomolecular state of the oligonucleotides. CD spectra indicated involvement of all guanines of d(GT)(8) and d(GT)(16) in G-quartets, while dT(GT)(7), d(GT)(12) and d(GT)(20) were shown to be only partially ordered. The schemes of the d(GT)(8) and d(GT)(16) folds are suggested.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Circular Dichroism
  • DNA, Single-Stranded / chemistry*
  • Ethidium / chemistry
  • G-Quadruplexes*
  • Humans
  • Nucleic Acid Conformation
  • Polydeoxyribonucleotides / chemistry*
  • Thermodynamics
  • Transition Temperature

Substances

  • DNA, Single-Stranded
  • Polydeoxyribonucleotides
  • polydeoxy(guanine-thymine) nucleotide
  • Ethidium