Interaction of polycationic Ni(II)-salophen complexes with G-quadruplex DNA.
A series of nine Ni(II) salophen complexes involving one, two, or three alkyl-imidazolium side-chains was prepared. The lengths of the side-chains were varied from one to three carbons. The crystal structure of one complex revealed a square planar geometry of the nickel ion. Fluorescence resonance energy transfer melting of G-quadruplex structures in the presence of salophen complex were performed. The G-quadruplex DNA structures were stabilized in the presence of the complexes, but a duplex DNA was not. The binding constants of the complexes for parallel and antiparallel G-quadruplex DNA, as well as hairpin DNA, were measured by surface plasmon resonance. The compounds were selective for G-quadruplex DNA, as reflected by equilibrium dissociation constant KD values in the region 0.1-1 μM for G-quadruplexes and greater than 2 μM for duplex DNA. Complexes with more and shorter side-chains had the highest binding constants. The structural basis for the interaction of the complexes with the human telomeric G-quadruplex DNA was investigated by computational studies: the aromatic core of the complex stacked over the last tetrad of the G-quadruplex with peripherical cationic side chains inserted into opposite grooves. Biochemical studies (telomeric repeat amplification protocol assays) indicated that the complexes significantly inhibited telomerase activity with IC50 values as low as 700 nM; the complexes did not significantly inhibit polymerase activity.
Université Grenoble Alpes , Département de Chimie Moléculaire, UMR CNRS 5250, BP 53, 38041 Grenoble Cedex 9, France.
Laureline
L
Lecarme
Enora
E
Prado
Aurore
A
De Rache
Marie-Laure
ML
Nicolau-Travers
Romaric
R
Bonnet
Angeline
A
van Der Heyden
Christian
C
Philouze
Dennis
D
Gomez
Jean-Louis
JL
Mergny
Hélène
H
Jamet
Eric
E
Defrancq
Olivier
O
Jarjayes
Fabrice
F
Thomas
D054856:G-Quadruplexes; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*
D009942:Organometallic Compounds