Nuclear Science and Techniques ›› 2019, Vol. 42 ›› Issue (4): 40501-040501.doi: 10.11889/j.0253-3219.2019.hjs.42.040501

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High-resolution imaging of single-molecule streptavidin using atomic force microscopy based on DNA origami

Tong SUN1,2,Wenjing LIU1,2,Ping ZHANG1,2,Lin LI3,Bin LI1()   

  1. 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. College of Sciences, Ningbo University, Ningbo 315211, China
  • Received:2019-01-28 Revised:2019-02-21 Online:2019-04-10 Published:2019-04-18
  • Contact: Bin LI E-mail:libin@sinap.ac.cn
  • About author:<named-content content-type="corresp-name">SUN Tong</named-content>, female, born in 1993, graduated from Liaoning University in 2016, master student, focusing on single molecule operating|<named-content content-type="corresp-name">SUN Tong</named-content>, female, born in 1993, graduated from Liaoning University in 2016, master student, focusing on single molecule operating|LI Bin, E-mail: <email>libin@sinap.ac.cn</email>
  • Supported by:
    Supported by National Natural Science Foundation of China (No.31670871, No.11674344, No.U1632125, No.21675167), the National Key Research and Development Program (No.2016YFA0201200), the Key Research Program of Frontier Sciences, Chinese Academy of Sciences(No.QYZDJ-SSW-SLH019, No.QYZDJ-SSW-SLH031)

Abstract: Background

The strong non-covalent interaction between streptavidin (STV) and biotin has been applied to various fields including molecular biology, immunology and biotechnology. The unique binding ability of STV to biotin is closely related to its structure. The crystal analysis results show that STV is a tetramer protein. Atomic force microscopy (AFM) plays an important role in studying the structure and function of proteins because it can provide morphological information of individual biomolecules in liquid environment. However, resolving STV with high-resolution AFM imaging remains challenge due to the small size and soft property.

Purpose

This study aims to obtain high resolution single molecule STV images by AFM.

Methods

With modified biotin location on DNA origami, the addressable DNA origami was employed to selectively fix STVs. Then, AFM was used for image processing of STVs.

Results

The single-molecule STV image at high-resolution was obtained. The observed STV showed an "hourglass-shaped" structure which consisted well with its crystal structure. At the same time, we noted that the STV morphology was susceptible to the effect of the loading force, indicating that it may be related to the flexibility of STVs.

Conclusion

The simple and convenient method will provide a new way for studying the morphology and function of biomolecules.

Key words: Atomic force microscopy, Single-molecule, High-resolution imaging, Streptavidin, DNA origami

CLC Number: 

  • Q71