Specific DNA G-quadruplexes bind to ethanolamines.

A significant number of G-quadruplex-forming sequences have been revealed in human genome by bioinformatic searches, implying that G-quadruplexes may be involved in important biological processes and may be new chemotherapeutic targets. Therefore, it is important to discover the potential interactions of G-quadruplexes with other molecules or groups. Here we describe a class of G-quadruplexes, which can bind to ethanolamine groups that widely exist in biomolecules and drug molecules. The specific interaction of these G-quadruplexes with ethanolamine groups was identified by high performance affinity chromatography (HPAC) using immobilized ethanolamine and diethanolamine as stationary phase reagents. The circular dichroism (CD) spectra and native polyacrylamide gel electrophoresis (PAGE) show that these ethanolamine binding quadruplexes adopt an intramolecularly parallel structure. The relationship of ethanolamine binding and G-quadruplexe structure provides new clues for the G-quadruplex-related studies as well as for the molecular designs of therapeutic reagents. (c) 2009 Wiley Periodicals, Inc. Biopolymers 91: 874-883, 2009.