Binding properties of chiral ruthenium(II) complexes Λ- and Δ-[Ru(bpy)2dppz-11-CO2Me]2+ toward the triplex RNA poly(U)•poly(A)*poly(U).

Binding properties of chiral ruthenium(II) complexes Λ- and Δ-[Ru(bpy)2dppz-11-CO2Me]2+ toward the triplex RNA poly(U)•poly(A)*poly(U).
J Inorg Biochem. 2018 May 24;186:51-59
Authors: Ni W, Liu X, Tan L
Abstract
Two chiral ruthenium(II) complexes containing ligand dppz-CO2Me (dppz-11-CO2Me = dipyrido[3,2-a,2',3'-c]phenazine-11-carboxylic acid methyl ester), Δ-[Ru(bpy)2dppz-11-CO2Me]2+ (bpy = 2,2'-bipyridine; Δ-1) and Λ-[Ru(bpy)2dppz-11-CO2Me]2+ (Λ-1), were synthesized and characterized. The binding of the two enantiomers with the triplex RNA poly(U)•poly(A)*poly(U) was carried out by various biophysical techniques. Analysis of the absorption and fluorescence features indicates that the binding strengths of the two enantiomers toward the triplex RNA differ only slightly from each other. The total increase in viscosity and shape of the curves for the triplex RNA with Λ-1 is similar to that with Δ-1, suggesting the binding modes of two enantiomers with the triplex RNA are intercalation. Thermal melting measurements indicate that the stabilization effects clearly depended on the concentrations of Λ-1 and Δ-1. However, the third-strand stabilizing effect of Δ-1 dramatically differs from that of Λ-1 when they interact with the chiral environment of the RNA triple at pH = 7.0 and [Na+] = 35 mM. Combined with the CD (CD = circular dichroism) variations of the triplex RNA with either Λ-1 or Δ-1, the rea...

Source: Journal of Inorganic Biochemistry - May 24, 2018 Category: Biochemistry Authors: Ni W, Liu X, Tan L Tags: J Inorg Biochem Source Type: research