Ion-responsive hemin-G-quadruplexes for switchable DNAzyme and enzyme functions

Miguel Angel Aleman-Garcia, Ron Orbach, Itamar Willner

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

Programmed nucleic acid sequences undergo K+ ion-induced self-assembly into G-quadruplexes and separation of the supramolecular structures by the elimination of K+ ions by crown ether or cryptand ion-receptors. This process allows the switchable formation and dissociation of the respective G-quadruplexes. The different G-quadruplex structures bind hemin, and the resulting hemin-G-quadruplex structures reveal horseradish peroxidase DNAzyme catalytic activities. The following K+ ion/receptor switchable systems are described: 1)The K+-induced self-assembly of the Mg2+-dependent DNAzyme subunits into a catalytic nanostructure using the assembly of G-quadruplexes as bridging unit. 2)The K +-induced stabilization of the anti-thrombin G-quadruplex nanostructure that inhibits the hydrolytic functions of thrombin. 3)The K +-induced opening of DNA tweezers through the stabilization of G-quadruplexes on the "tweezers' arms" and the release of a strand bridging the tweezers into a closed structure. In all of the systems reversible, switchable, functions are demonstrated. For all systems two different signals are used to follow the switchable functions (fluorescence and the catalytic functions of the derived hemin-G-quadruplex DNAzyme). Bound to change: Switchable DNA devices were designed by sequence-programmed nucleic acids that undergo K+-ion-induced self-assembly into G-quadruplexes and the separation of the resulting nanostructures by K+ receptors, such as crown ether or cryptand (see scheme).

Original languageEnglish
Pages (from-to)5619-5624
Number of pages6
JournalChemistry - A European Journal
Volume20
Issue number19
DOIs
StatePublished - 5 May 2014
Externally publishedYes

Keywords

  • G-quadruplex
  • crown ether
  • cryptand
  • thrombin
  • tweezers

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