title: Shedding light on the interactions of guanine quadruplexes with tricationic metalloporphyrins.
abstract: G-quadruplex DNA presents a potential target for the design and development of novel anticancer drugs. The porphyrin TMPyP4 was early reported to be a suitable motif for G-quadruplex DNA interaction. We inserted various metal ions such as Zn(II), Cu(II), Co(III) in the center of the aromatic core of tricationic TMPyP4-like porphyrin and examined their interactions with an antiparallel G-quadruplex DNA by a combination of spectroscopy and Job plot methods. Porphyrin metallation allowed the conclusion that the presence of one axial ligand perpendicular to the aromatic plane did not hamper π-π stacking interactions between quadruplex and the aromatic parts of porphyrin on the other face while porphyrin with two axial ligands was unable to undergo such interaction due to geometrical factors. Free base porphyrin and porphyrin without axial ligands are able to stabilize the quadruplex structure to a greater extent than the other metal complexes and thus may be potential anti-cancer drugs.
authors: School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, No. 280, Waihuandong Road, Education Mega Centre, Guangzhou 510006, PR China. zhaoping666@163.com
authors: Ping
authors: P
authors: Zhao
authors: Jia-Zheng
authors: JZ
authors: Lu
authors: Feng-Ying
authors: FY
authors: Hong
authors: Bing-Hui
authors: BH
authors: Ou
authors: Feng-duan
authors: FD
authors: Zhang
authors: Li-na
authors: LN
authors: Ma
authors: Hai-min
authors: HM
authors: Guo
mesh_terms: D000042:Absorption; D002412:Cations / Q000737:chemistry; D002942:Circular Dichroism; D031541:Fluorescence Resonance Energy Transfer; D054856:G-Quadruplexes; D008665:Metalloporphyrins / Q000737:chemistry*; D009691:Nucleic Acid Denaturation; D013059:Spectrum Analysis, Raman; D013696:Temperature; D017186:Titrimetry
chemical_list: D002412:Cations; D008665:Metalloporphyrins