Title
Effect of Ionic Strength on the Thermal Stability of DNA Origami Nanostructures
Author
Hanke, Marcel, Emilia Tomm, Guido Grundmeier, and Adrian Keller
Year
2023
Journal
ChemBioChem
Abstract
The stability of DNA origami nanostructures in aqueous media is closely tied to the presence of cations that screen electrostatic inter-helix repulsion. Here, the thermal melting behavior of different DNA origami nanostructures is investigated in dependence of Mg2+ concentration and compared to calculated ensemble melting temperatures of the staple strands used in DNA origami folding. Strong deviations of the measured DNA origami melting temperatures from the calculated ones are observed, in particular at high ionic strength where the melting temperature saturates and becomes independent of ionic strength. The degree of deviation between the measured and calculated melting temperatures further depends on the superstructure and in particular the mechanical properties of the DNA origami nanostructures. This indicates that thermal stability of a given DNA origami design at high ionic strength is governed predominantly not by electrostatic inter-helix repulsion but mostly by mechanical strain.
Instrument
FP-8200
Keywords
mechanical strain