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A Twisting Electronic Nanoswitch Made of DNA
Author(s) -
Huang Yu Chuan,
Sen Dipankar
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201407729
Subject(s) - guanine , dna , nucleobase , chemistry , conformational isomerism , g quadruplex , electronic structure , chemical physics , stereochemistry , crystallography , biophysics , computational chemistry , molecule , nucleotide , biochemistry , biology , organic chemistry , gene
Single‐stranded DNAs and RNAs that are rich in the nucleobase guanine form four‐stranded G‐quadruplexes, which are held together by hydrogen‐bonded guanine quartets. In aqueous solution, both DNA duplexes and G‐quadruplexes are modest conductors of electrical charge. A tight, topologically constrained DNA construct called twDNA is now reported, in which a core of four guanine‐rich single strands structurally and electronically links together four DNA double helices. The addition and removal of K + or Sr 2+ cations promote alternative conformers of twDNA, which have strikingly distinct electronic properties. Unlike DNA mechano‐electronic switches that require large conformational changes, twDNA requires only modest twisting/untwisting structural attenuations to achieve electronic switching.