Verification of specific G-quadruplex structure by using a novel cyanine dye supramolecular assembly: II. The binding characterization with specific intramolecular G-quadruplex and the recognizing mechanism.
The supramolecular assembly of a novel cyanine dye, 3,3'-di(3-sulfopropyl)-4,5,4',5'-dibenzo-9-ethyl-thiacarbocyanine triethylammonium salt (ETC) was designed to verify specific intramolecular G-quadruplexes from duplex and single-strand DNAs. Spectral results have shown that ETC presented two major distinct signatures with specific intramolecular G-quadruplexes in vitro: (i) dramatic changes in the absorption spectra (including disappearance of absorption peak around 660 nm and appearance of independent new peak around 584 nm); (ii) approximately 70 times enhancement of fluorescence signal at 600 nm. Furthermore, based on (1)H-nuclear magnetic resonance and circular dichroism results, the preferring binding of ETC to specific intramolecular G-quadruplexes probably result from end-stacking, and the loop structure nearby also plays an important role.
Yang
Qianfan
Q
Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
Xiang
Junfeng
J
Yang
Shu
S
Li
Qian
Q
Zhou
Qiuju
Q
Guan
Aijiao
A
Zhang
Xiufeng
X
Zhang
Hong
H
Tang
Yalin
Y
Xu
Guangzhi
G
D002232:Carbocyanines / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
C548165:3,3'-di(3-sulfopropyl)-4,5,4',5'-dibenzo-9-ethyl-thiacarbocyanine; D002232:Carbocyanines; D004277:DNA, Single-Stranded; D005456:Fluorescent Dyes; D004247:DNA