Orientation of ends of G-quadruplex structure investigated with end-extended oligonucleotides

Abstract

The human telomere terminus can adopt the structure of a G-quadruplex. This structure has become an attractive target for anticancer drugs, because it effectively inhibits telomerase activity. In this study, we investigated the orientation of both 5' and 3' ends of the stable G-quadruplex structure. To verify the orientation, we designed end-extended G-quadruplex forming oligonucleotides. We carried out gel electrophoresis and the NMR analysis and found that the ends of the stable G-quadruplex structure are located on opposite faces of each of the quadruplexes.