Eilatin Ru(II) complexes display anti-HIV activity and enantiomeric diversity in the binding of RNA

Eilatin-containing octahedral ruthenium complexes inhibit HIV-1 replication in CD4+ HeLa cells and in human peripheral blood monocytes with IC(50) values of approximately 1 microM. Similar metal complexes that lack eilatin display 15-100-fold lower anti-HIV activities. [Ru(bpy)(2)"pre-eilatin"](2+), a complex that contains a nonplanar analogue of eilatin, shows significantly lower nucleic acid binding and lower anti-HIV activity than eilatin complexes. This result indicates that the extended planar surface presented by eilatin is important for both activities. Rev peptide and ethidium bromide displacement assays are used to probe the nucleic acid affinity and specificity of Lambda- and Delta-[Ru(bpy)(2)eilatin](2+). Two HIV-1 RNA sites are compared and a significant binding preference for the Rev response element over the transactivation response region is found. Simple DNA duplexes show a consistent selectivity for Lambda-[Ru(bpy)(2)eilatin](2+) compared to Delta-[Ru(bpy)(2)eilatin](2+), while RNAs show more diverse enantiomeric selectivities.