In-situ Configuration Study On Segmented DNA Origami Nanotubes

Biomacromolecule nanotubes play an important role in physiological processes such as transmembrane ion/molecular channels,intracellular transport and intercellular communication.Although genetically encoded protein nanotubes predominate in the body,with the development of DNA nanotechnology,the in vitro construction of biomimetic DNA nanotubes has gradually attracted people's interest.Researchers hope to construct DNA nanotubes with user-defined structural features that are biologically relevant,which facilitates the application of these nanotubes in different fields,such as drug delivery and controlled release,nanomaterial templates,and artificial membrane channels.DNA nanotechnology provides a powerful bottom-up approach to building nanoscale materials of any size and shape.Typical DNA nanotubes can be assembled with parallel arrays of DNA duplexes or lattice closure of DNA Tiles.These artificial DNA nanotubes are customizable and site-specifically modified to achieve biomimetic functions,including ion/molecular channels,bioreactors,drug delivery,and biomolecular sensing.However,little is known about the structural information of DNA nanotubes in solution.Herein,we report an in-situ characterization of DNA nanotubes using synchrotron small-angle X-ray scattering(SAXS),which consists of cells with a defined length distribution.By combining experimental and theoretical studies,we demonstrate that SAXS can help us to obtain the in-situ structural information of heterogeneous mixtures of DNA nanotubes.The structural data obtained by SAXS is consistent with the results of atomic force microscopy(AFM),transmission electron microscopy(TEM)and dynamic light scattering(DLS).In particular,SAXS data reveals true conformational information in the solution state of these DNA nanotubes,such as the length distribution(several bymicrons)and diameter(about 25 nm)in solution,which are unavailable by using other methods.Results show that SAXS is a reliable DNA nanotube structure analysis method that can help us rationally design other nanotube structures in future work.