Dinuclear nickel(II) triple-stranded supramolecular cylinders: syntheses, characterization and G-quadruplexes binding properties.
Three dinuclear nickel triple-stranded supramolecular cylinders [Ni2(L1)3][ClO4]4 (1), [Ni2(L2)3][ClO4]4 (2) and [Ni2(L3)3][ClO4]4 (3) with bis(pyridylimine) Schiff base containing triphenyl groups in the spacers as ligands were synthesized and characterized. The human telomeric G-quadruplexes binding properties of cylinders 1-3 were evaluated by means of UV-Vis spectroscopy, circular dichroism (CD) spectroscopy and fluorescence resonance energy transfer (FRET) melting assay. UV-Vis studies revealed that the supramolecular cylinders 1-3 could bind to G-quadruplex DNA with high binding constants (Kb values ranging from 0.11-2.2×10(6) M(-1)). FRET melting studies indicated that the cylinders 1-3 had much stronger stabilizing effect on G-quadruplex DNA (ΔTm up to 24.5°C) than the traditional cylinder Ni2L3(4+) just containing diphenylmethane spacers (ΔTm=10.6 °C). Meanwhile, cylinders 1-3 were found to have a modest degree of selectivity for the quadruplex DNA versus duplex DNA in competition FRET assays. Moreover, CD spectroscopy revealed that complex 1 could induce G-quadruplex formation in the absence of metal ions solution and convert antiparallel G-quadruplex into hybrid structure in Na(+) solution. These results provided a new insight into the development of supramolecular cylinders as potential anticancer drugs targeting G-quadruplex DNA.
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Xin-Xin
XX
Xu
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Jing-Jing
JJ
Na
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Fei-Fei
FF
Bao
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Wen
W
Zhou
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Chun-Yan
CY
Pang
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Zaijun
Z
Li
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China; The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China. Electronic address: zhiguogu@jiangnan.edu.cn.
Zhi-Guo
ZG
Gu
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D003198:Computer Simulation; D004247:DNA / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D054856:G-Quadruplexes; D006801:Humans; D008958:Models, Molecular; D009532:Nickel / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D016615:Telomere / Q000378:metabolism; D013816:Thermodynamics
D009532:Nickel; D004247:DNA; C427203:calf thymus DNA
DNA binding; Dinuclear; G-quadruplex; Schiff base; Stabilizers; Supramolecular cylinders