Researchers used C-Trap™ optical tweezers to study the energy landscapes associated with the formation of specific DNA origami structures, which is the folding of single-stranded DNA into pre-designed configurations.
In the study, Kosinski et al. analyzed topological and sequence-dependent folding features in DNA origami, and determined the energy landscape associated with different conformations. The findings highlight new ways to guide DNA origami folding in order to favor the formation of distinct isomers.
By trapping the DNA between two beads, the team could stretch the structure with about 5 pN pre-tension and quantify the energies required for isomer formation.
The researchers found two distinct interconverting isomer states as well as an intermediary open-state structure. According to the measurements with C-Trap™, assembly of one of the isomers was energetically more favorable but also more accessible to the open state, thus less stable. In contrast, to establish the second isomer, the DNA structure required higher energy to escape initial structural stresses but eventually reached a minimum of energy that trapped the structure in a more irreversible and stable isomeric state.
The C-Trap™ Optical Tweezers – Fluorescence & Label-free Microscopy used in this paper is made commercially available by LUMICKS. Are you interested in using the instrument for your research? Please feel free to contact us for a demo or quote.