Silver (I) as DNA glue: Ag(+)-mediated guanine pairing revealed by removing Watson-Crick constraints.

ABSTRACT: Metal ion interactions with DNA have far-reaching implications in biochemistry and DNA nanotechnology. Ag(+) is uniquely interesting because it binds exclusively to the bases rather than the backbone of DNA, without the toxicity of Hg(2+). In contrast to prior studies of Ag(+) incorporation into double-stranded DNA, we remove the constraints of Watson-Crick pairing by focusing on homo-base DNA oligomers of the canonical bases. High resolution electro-spray ionization mass spectrometry reveals an unanticipated Ag(+)-mediated pairing of guanine homo-base strands, with higher stability than canonical guanine-cytosine pairing. By exploring unrestricted binding geometries, quantum chemical calculations find that Ag(+) bridges between non-canonical sites on guanine bases. Circular dichroism spec

SUBMITTER: Swasey SM 

PROVIDER: S-EPMC4431418 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature