Understanding the structure and stability of quadruplex nucleic acids formed from human telomeric sequences

The human telomere is a sequence of DNA found at the ends of chromosomes consisting of the repeat d(TT AGGG) and serves to protect genetic information against chromosomal degradation. The human telomere is unique in its ability to fold into a Gquadruplex secondary structure with the ability to inhibit telomerase, increasing the interest of G-quadruplex structures over the years. Our work with the human telomere is based upon three main questions: How is the structure and stability of quadruplexes affected by 1) altering the sequence of the loops?; 2) modifying the length of the repeat?; and 3) changing the nature of the counter ion present in solution? In order to answer these questions we have studied all permutations of (XXXGGG)4 where X= Tor A, (TTAGGG)x where x= 1, 2, or 4, as well as investigate the effects of sodium and/or potassium upon all sequences in our library.