Encapsulating a single G-quadruplex aptamer in a protein nanocavity

Ji Wook Shim, Li Qun Gu

Research output: Contribution to journalArticlepeer-review

42 Scopus citations

Abstract

The α-hemolysin (αHL) protein pore has many applications in biotechnology. This article describes a single-molecule manipulation system that utilizes the nanocavity enclosed by this pore to noncovalently encapsulate a guest molecule. The guest is the thrombin-binding aptamer (TBA) that folds into the G-quadruplex in the presence of cations. Trapping the G-quadruplex in the nanocavity resulted in characteristic changes to the pore conductance that revealed important molecular processes, including spontaneous unfolding of the quartet structure and translocation of unfolded DNA in the pore. Through detection with Tag-TBA, we localized the G-quadruplex near the entry of the β-barrel inside the nanocavity, where the molecule vibrates and rotates to different orientations. This guest - nanocavity supramolecular system has potential for helping to understand single-molecule folding and unfolding kinetics.

Original languageEnglish (US)
Pages (from-to)8354-8360
Number of pages7
JournalJournal of Physical Chemistry B
Volume112
Issue number28
DOIs
StatePublished - Jul 17 2008

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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