Duplex formation at the 5' end affects the quadruplex conformation of the human telomeric repeat overhang in sodium but not in potassium.

ABSTRACT: Human telomeres contain numerous copies of the (TTAGGG)(n).(AATCCC)(n) repeated sequence with multiple TTAGGG repeats in 3' single-stranded overhangs. Single-stranded oligonucleotides consisting of four TTAGGG repeats can fold into various intramolecular quadruplex structures stabilized by quartets of guanines. The quadruplex structures are believed to play a role in telomere functions and considered as targets for anticancer drug design. In an effort to create a more realistic model of telomeric DNA, we designed oligonucleotides containing a duplex region at the 5' end and four telomeric repeats in the 3' overhang. We applied CD spectroscopy and (125)I radioprobing to determine the conformation of the quadruplexes formed in the 3' overhangs. We found that in the presence of NaCl the confo

SUBMITTER: Gaynutdinov TI 

PROVIDER: S-EPMC2810119 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature