State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Department of Chemistry, New York University, New York, New York 10003, United States.
J Am Chem Soc. 2022 Apr 20;144(15):6759-6769. doi: 10.1021/jacs.1c13601. Epub 2022 Apr 6.
The overwinding and underwinding of DNA duplexes between junctions have been used in designing left- and right-handed DNA origami nanostructures, respectively. For DNA tubes obtained from self-assembled tiles, only a theoretical approach of the intrinsic curvature of the tiles has been previously used to explain their formation. Details regarding the quantitative and structural descriptions of the tile's intrinsic curvature in DNA nanostructures have so far never been addressed. In this work, we designed three types of tile cores built around a circular scaffold using three- and four-branched junctions. Joining the tile cores with arms having two kinds of inter-tile distances, an odd and an even number of DNA half-turns, tended to form planar 2D lattices and tubes, respectively. Streptavidin bound to biotin was used as a labeling technique to characterize the inside and outside surfaces of the tubes and thereby the tile conformation of dihedrals with addressable faces. DNA tubes with either right- or left-handed chirality were obtained by the coupling of the intrinsic curvature of the tiles with the arm twist. We were able to assign the chiral indices (,) to a tube with its structure resolved by AFM at the single-tile level and therefore to estimate the global curvature of the tube (or its component tile) using a regular polygon model that approximated its transverse section. A deeper understanding of the integrated actions of different types of twisting forces on DNA tubes will be extremely helpful in engineering more elaborate DNA nanostructures in the future.
DNA 双链在连接点处的过度缠绕和欠缠绕分别被用于设计左手和右手 DNA 折纸纳米结构。对于自组装瓦片形成的 DNA 管，之前仅使用瓦片的固有曲率的理论方法来解释其形成。关于 DNA 纳米结构中瓦片固有曲率的定量和结构描述的细节，迄今为止尚未涉及。在这项工作中，我们设计了三种类型的核心瓦片，它们围绕着一个圆形支架使用三分叉和四分叉连接点构建。通过使用具有两种不同瓦片间距离的臂将核心瓦片连接起来，奇数和偶数个 DNA 半圈，分别倾向于形成平面 2D 晶格和管。链霉亲和素与生物素的结合被用作标记技术，以表征管的内外表面，从而对可寻址面的二面角的瓦片构象进行了表征。通过瓦片固有曲率与臂扭转的耦合，可以获得具有右手或左手手性的 DNA 管。我们能够通过原子力显微镜在单瓦片水平上解析管的结构来为管分配手性指标（，），并使用正多边形模型来估计管的整体曲率（或其组成瓦片），该模型近似其横截面。深入了解不同类型扭曲力对 DNA 管的综合作用，将在未来工程更精细的 DNA 纳米结构方面提供极大的帮助。
