Synthesis and Evaluation of New Spacers for Use as dsDNA End-Caps
journal contributionposted on 2010-08-18, 00:00 authored by Pei-Sze Ng, Brian M. Laing, Ganesan Balasundarum, Maneesh Pingle, Alan Friedman, Donald E. Bergstrom
A series of aliphatic and aromatic spacer molecules designed to cap the ends of DNA duplexes have been synthesized. The spacers were converted into dimethoxytrityl-protected phosphoramidites as synthons for oligonucleotides synthesis. The effect of the spacers on the stability of short DNA duplexes was assessed by melting temperature studies. End-caps containing amide groups were found to be less stabilizing than the hexaethylene glycol spacer. End-caps containing either a terthiophene or a naphthalene tetracarboxylic acid diimide were found to be significantly more stabilizing. The former showed a preference for stacking above an A•T base pair. Spacers containing only methylene (−CH2−) and amide (−CONH−) groups interact weakly with DNA and consequently may be optimal for applications that require minimal influence on DNA structure but require a way to hold the ends of double-stranded DNA together.