Molecules (Nov 2017)

DNA G-Wire Formation Using an Artificial Peptide is Controlled by Protease Activity

  • Kenji Usui,
  • Arisa Okada,
  • Shungo Sakashita,
  • Masayuki Shimooka,
  • Takaaki Tsuruoka,
  • Shu-ichi Nakano,
  • Daisuke Miyoshi,
  • Tsukasa Mashima,
  • Masato Katahira,
  • Yoshio Hamada

DOI
https://doi.org/10.3390/molecules22111991
Journal volume & issue
Vol. 22, no. 11
p. 1991

Abstract

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The development of a switching system for guanine nanowire (G-wire) formation by external signals is important for nanobiotechnological applications. Here, we demonstrate a DNA nanostructural switch (G-wire <--> particles) using a designed peptide and a protease. The peptide consists of a PNA sequence for inducing DNA to form DNA–PNA hybrid G-quadruplex structures, and a protease substrate sequence acting as a switching module that is dependent on the activity of a particular protease. Micro-scale analyses via TEM and AFM showed that G-rich DNA alone forms G-wires in the presence of Ca2+, and that the peptide disrupted this formation, resulting in the formation of particles. The addition of the protease and digestion of the peptide regenerated the G-wires. Macro-scale analyses by DLS, zeta potential, CD, and gel filtration were in agreement with the microscopic observations. These results imply that the secondary structure change (DNA G-quadruplex <--> DNA/PNA hybrid structure) induces a change in the well-formed nanostructure (G-wire <--> particles). Our findings demonstrate a control system for forming DNA G-wire structures dependent on protease activity using designed peptides. Such systems hold promise for regulating the formation of nanowire for various applications, including electronic circuits for use in nanobiotechnologies.

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