Table of Contents
ISRN Biochemistry
Volume 2013, Article ID 631875, 7 pages
Research Article

Variable-Temperature Size Exclusion Chromatography for the Study of the Structural Changes in G-Quadruplex

1Solution Equilibria and Chemometrics Group (Associate Unit UB-CSIC), Department of Analytical Chemistry, University of Barcelona, Diagonal 647, 08028 Barcelona, Spain
2Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), CIBER-BBN Networking Research Centre on Bioengineering, Biomaterials and Nanomedicine, Jordi Girona 18-26, 08034 Barcelona, Spain

Received 22 July 2013; Accepted 26 September 2013

Academic Editors: E. Kandimalla and Y. Mely

Copyright © 2013 Sanae Benabou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The conformational equilibria of a guanine-rich sequence found at the promoter region of the human c-kit oncogene are studied by means of circular dichroism spectroscopy (CD) and variable-temperature size exclusion chromatography (SEC). It is shown that the wild sequence ckit21 exists as a mixture of monomeric and multimeric G-quadruplexes. Appropriate mutation of several bases in the wild sequence produces the shift from parallel to antiparallel G-quadruplex, as well as the disappearance of multimeric species. The shift from the antiparallel to the parallel conformation induced by temperature is reflected in both CD and SEC profiles.