Sensor Design Based on Structure Adjustment in Loops of G-quadruplex
10.11895/j.issn.0253-3820.140338
- VernacularTitle:利用对G-四链体环部的构型调节进行传感器的设计
- Author:
Nana DUAN
;
Na WANG
;
Wei YANG
;
Deming KONG
- Publication Type:Journal Article
- Keywords:
G-quadruplex;
DNAzyme;
Sensor;
Mercurry(Ⅱ);
Cysteine
- From:
Chinese Journal of Analytical Chemistry
2014;(10):1414-1420
- CountryChina
- Language:Chinese
-
Abstract:
The effects of linking loop structure between guanine ( G) repeats on G-quadruplex formation were investigated. The results show that the unfavorable effects of long linking loops on G-quadruplex formation can be overcome by introducing double-stranded structures in linking loop regions. This finding provides a new way for sensor design. The activity of G-quadruplex DNAzyme can be tuned by utilizing target-mediated formation of double-stranded structures in loops. As an example, T-T mismatches are introduced in loops to destroy double-stranded structures. The stabilization of Hg2+ to T-T mismatches promotes the reformation of double-stranded structures. Correspondingly, the oligonucleotide folds into G-quadruplex, which binds with hemin to form peroxidase-like G-quadruplex DNAzyme. Hg2+ sensor is designed based on this principle. Using this method, Hg2+ quantitation is achieved in the concentration range of 10-700 nmol/L, with a detection limit of 8. 7 nmol/L. Cysteine will compete with T bases to bind with Hg2+, releasing Hg2+from T-Hg2+-T base pairs. Thus cysteine can also be quantified with this system in the concentration range of 20-700 nmol/L, with a detection limit of 14 nmol/L.
