Charge Neutralization Drives the Shape Reconfiguration of DNA Nanotubes |
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| Authors: | Pi Liu Yan Zhao Xiaoguo Liu Jixue Sun Dede Xu Yang Li Qian Li Lihua Wang Sichun Yang Prof. Chunhai Fan Prof. Jianping Lin |
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| Affiliation: | 1. State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China;2. Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China;3. Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China;4. Center for Proteomics and Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA |
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| Abstract: | Reconfiguration of membrane protein channels for gated transport is highly regulated under physiological conditions. However, a mechanistic understanding of such channels remains challenging owing to the difficulty in probing subtle gating‐associated structural changes. Herein, we show that charge neutralization can drive the shape reconfiguration of a biomimetic 6‐helix bundle DNA nanotube (6HB). Specifically, 6HB adopts a compact state when its charge is neutralized by Mg2+; whereas Na+ switches it to the expanded state, as revealed by MD simulations, small‐angle X‐ray scattering (SAXS), and FRET characterization. Furthermore, partial neutralization of the DNA backbone charges by chemical modification renders 6HB compact and insensitive to ions, suggesting an interplay between electrostatic and hydrophobic forces in the channels. This system provides a platform for understanding the structure–function relationship of biological channels and designing rules for the shape control of DNA nanostructures in biomedical applications. |
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| Keywords: | DNA nanotechnology molecular channels molecular dynamics SAXS shape reconfiguration |
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