 |
[email protected] |
 |
3275638434 |
 |
 |
| Paper Publishing WeChat |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Synthesis, Crystal Structure and Interactions with Different G-quadruplex DNA and ctDNA of Zn-CAP
Caifeng Liu, Yunfeng An, Yan Peng, Qiping Qin, Hui Zhong, Chao Lu and Guohai Zhang
Full-Text PDF
XML 105 Views
DOI:10.17265/1934-7375/2014.05.002
State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
In this study, one mononuclear zinc(II) complex with 1,2-bis CAP ((5-chlorosalicylidene amino)-phenylene): C22Cl3N2O3.5Zn1.5 H0.125 (Zn-CAP) was synthesized. The binding properties of Zn-CAP with G-quadruplex DNA and ctDNA (calf thymus DNA) were examined by fluorescence, CD (circular dichroism) spectroscopic and FRET (fluorescence resonance energy transfer) assay. In the fluorescence emission spectral analysis, the addition of three series of G-quadruplex DNA (G4-HTG21, G4-Pu27 and G4-c-kit-1) into the Zn-CAP solution induced moderate or add hypochromicity with total quenching ratios of 10.73%, 15.07% and 8.59% in the presence of K+ were achieved, respectively. While the addition of ctDNA under same condition only caused 7.08% quenching on the fluorescence emission of Zn-CAP. In the CD spectral analysis, the interaction with Zn-CAP could induce significant spectral changes on the CD absorption of G4-HTG21, G4-Pu27 and G4-c-kit-1, with 106.00%, 93.06%, 113.47% increment at 232 nm absorption, along with a 81.11%, 92.80%, 83.72% decrement at 295 nm or 270 nm absorption, which demonstrated that the antiparallel structure of G-quadruplex DNA is more stable in the presence of Zn-CAP. Comparatively, the addition of Zn-CAP could induce significant spectral changes on the CD absorption of double helix ctDNA, with 64.17% decrement on the positive peak absorption, along with a 90.91% increment on the negative peak absorption. On the other hand, in the FRET-melting assay analysis, it was clear that Zn-CAP at 0.5 equivalences could raise the melting temperature of G-quadruplex (F21T or FPu18T) by 3.45 oC and 15.85 oC, indicating an obvious stabilization effect of Zn-CAP on G-quadruplex in Pu27. All the results indicated that Zn-CAP exhibited higher binding affinity and binding intensity to G-quadruplex DNA than ctDNA, especially G-quadruplex Pu27.
Zn-CAP, G-quadruplex DNA, ctDNA, spectroscopy, FRET assay.