Related Experiment Video
Updated: May 28, 2026

In Vitro Chemical Mapping of G-Quadruplex DNA Structures by Bis-3-Chloropiperidines
Published on: May 12, 2023
Effects of site-specific guanine C8-modifications on an intramolecular DNA G-quadruplex
Christopher Jacques Lech1, Joefina Kim Cheow Lim, Jocelyn Mei Wen Lim
1School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
Abstract:
Understanding the fundamentals of G-quadruplex formation is important both for targeting G-quadruplexes formed by natural sequences and for engineering new G-quadruplexes with desired properties. Using a combination of experimental and computational techniques, we have investigated the effects of site-specific substitution of a guanine with C8-modified guanine derivatives, including 8-bromo-guanine, 8-O-methyl-guanine, 8-amino-guanine, and 8-oxo-guanine, within a well-defined (3 + 1) human telomeric G-quadruplex platform. The effects of substitutions on the stability of the G-quadruplex were found to depend on the type and position of the modification among different guanines in the structure. An interesting modification-dependent NMR chemical-shift effect was observed across basepairing within a guanine tetrad. This effect was reproduced by ab initio quantum mechanical computations, which showed that the observed variation in imino proton chemical shift is largely influenced by changes in hydrogen-bond geometry within the guanine tetrad.
Related Concept Videos
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
DNA Base Pairing
Inhibitors of Bacterial DNA Synthesis
Nucleotide Excision Repair
Proofreading
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...

