DNA mechatronic devices switched by K+ and by Sr2+ are structurally, topologically, and electronically distinct. Issue 8 (August 2015)

• Record Type: Journal Article
• Authors: Huang, Yu Chuan; Yu, Hua‐Zhong; Sen, Dipankar; Chaires, Jonathan; Chaires, Jonathan B.; Levene, Stephen D.
• Is Part Of: Biopolymers. Volume 103:Issue 8(2015)
• Page Start: 460
• Page End: 468
• Publication Date: 2015-08
• Subjects: Biopolymers -- Periodicals; Peptides -- Periodicals; Spectrum analysis -- Periodicals; 572.33
• DOI: 10.1002/bip.22595
• Languages: English
• ISSNs: 0006-3525

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>DNAs and RNAs that fold via the formation of guanine quartets form G‐quadruplexes that are often highly diverse in terms of architecture and topology. G‐quadruplexes are specifically stabilized by metal cations such as K⁺ and Sr²⁺, but not Li⁺. DNA duplexes that incorporate two separated clusters of GG mismatches ("P‐duplexes") can function as electronic switches, capable of toggling reversibly from a poorly conductive conformer (E) with only Li⁺ in the solution to a G‐quadruplex incorporating conformer of higher conductivity (C) in the presence of K⁺. Herein, we report results from fluorescence energy transfer, circular dichroism, charge conduction, and chemical footprinting experiments, which cumulatively demonstrate that P‐duplex E↔C transitions are genuinely mechatronic, with causally coupled mechanical and electronic states. We show, further, that the K⁺‐ and the Sr²⁺‐fuelled E↔C switching of a given P‐duplex are structurally, topologically, and electronically distinct from each other. A single DNA P‐duplex can thus exist in at least three distinguishable mechatronic states in aqueous solution. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 460–468, 2015.</p> </abstract>