Conformationally Gated Charge Transfer in DNA Three-Way Junctions.

Published

Journal Article (Letter)

Molecular structures that direct charge transport in two or three dimensions possess some of the essential functionality of electrical switches and gates. We use theory, modeling, and simulation to explore the conformational dynamics of DNA three-way junctions (TWJs) that may control the flow of charge through these structures. Molecular dynamics simulations and quantum calculations indicate that DNA TWJs undergo dynamic interconversion among "well stacked" conformations on the time scale of nanoseconds, a feature that makes the junctions very different from linear DNA duplexes. The studies further indicate that this conformational gating would control charge flow through these TWJs, distinguishing them from conventional (larger size scale) gated devices. Simulations also find that structures with polyethylene glycol linking groups ("extenders") lock conformations that favor CT for 25 ns or more. The simulations explain the kinetics observed experimentally in TWJs and rationalize their transport properties compared with double-stranded DNA.

Full Text

Duke Authors

Cited Authors

  • Zhang, Y; Young, RM; Thazhathveetil, AK; Singh, APN; Liu, C; Berlin, YA; Grozema, FC; Lewis, FD; Ratner, MA; Renaud, N; Siriwong, K; Voityuk, AA; Wasielewski, MR; Beratan, DN

Published Date

  • July 2015

Published In

Volume / Issue

  • 6 / 13

Start / End Page

  • 2434 - 2438

PubMed ID

  • 26266714

Pubmed Central ID

  • 26266714

Electronic International Standard Serial Number (EISSN)

  • 1948-7185

International Standard Serial Number (ISSN)

  • 1948-7185

Digital Object Identifier (DOI)

  • 10.1021/acs.jpclett.5b00863

Language

  • eng