title: Binding Behaviors for Different Types of DNA G-Quadruplexes: Enantiomers of [Ru(bpy)2(L)](2+) (L=dppz, dppz-idzo).
abstract: Polymorphic DNA G-quadruplex recognition has attracted great interest in recent years. The strong binding affinity and potential enantioselectivity of chiral [Ru(bpy)2 (L)](2+) (L=dipyrido[3,2-a:2',3'-c]phenazine, dppz-10,11-imidazolone; bpy=2,2'-bipyridine) prompted this investigation as to whether the two enantiomers, Δ and Λ, can show different effects on diverse structures with a range of parallel, antiparallel and mixed parallel/antiparallel G-quadruplexes. These studies provide a striking example of chiral-selective recognition of DNA G-quadruplexes. As for antiparallel (tel-Na(+)) basket G-quadruplex, the Λ enantiomers bind stronger than the Δ enantiomers. Moreover, the behavior reported here for both enantiomers stands in sharp contrast to B-DNA binding. The chiral selectivity toward mixed parallel/antiparallel (tel-K(+)) G-quadruplex of both compounds is weak. Different loop arrangements can change chiral complex selectivity for both antiparallel and mixed parallel/antiparallel G-quadruplex. Whereas both Δ and Λ isomers bind to parallel G-quadruplexes with comparable affinity, no appreciable stereoselective G-quadruplex binding of the isomers was observed. In addition, different binding stoichiometries and binding modes for Δ and Λ enantiomers were confirmed. The results presented here indicate that chiral selective G-quadruplex binding is not only related to G-quadruplex topology, but also to the sequence and the loop constitution.
authors.affiliation: Shanghai Key Laboratory of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092 (P.R. China). shishuo@tongji.edu.cn.
authors.forename: Shuo
authors.initials: S
authors.lastname: Shi
authors.affiliation: Shanghai Key Laboratory of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092 (P.R. China).
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Xu
authors.affiliation: Shanghai Key Laboratory of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092 (P.R. China).
authors.forename: Xing
authors.initials: X
authors.lastname: Gao
authors.affiliation: Shanghai Key Laboratory of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092 (P.R. China).
authors.forename: Hai-Liang
authors.initials: HL
authors.lastname: Huang
authors.affiliation: Shanghai Key Laboratory of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092 (P.R. China). tmyao@tongji.edu.cn.
authors.forename: Tian-Ming
authors.initials: TM
authors.lastname: Yao
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes / Q000187:drug effects*; D009690:Nucleic Acid Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010619:Phenazines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009942:Organometallic Compounds; D010619:Phenazines; C077849:bis(2,2'-bipyridyl)(dipyrido(3,2-alpha-2',3'-c)phenazine)ruthenium (II); D004247:DNA
keywords: G-quadruplexes; binding affinity; enantioselectivity; recognition; ruthenium complexes