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Updated: Aug 19, 2026
Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope
Published on: February 28, 2019
[Dynamic atomic force microscopic observation of the three-dimensional conformation of protein A-gold single
Yi-Gang Yu1, Ru-Xiang Xu, Ying-Qian Cai
1Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. yu-yg@tom.com
Objective:
To determine the three-dimensional (3D) conformation of staphylococcal protein A-gold (SPA-G) single molecule using atomic force microscope (AFM) so as to evaluate the feasibility of using this molecule for in situ labeling of the neuronal membrane protein.
Methods:
AFM was used to acquire the images of SPA-G binding to the surface of mica under physiological condition for determining the 3D conformation of the molecule.
Results:
SPA-G single molecule was shown to contain a characteristic structure with a chain in the shape of mirror image of the letter C, which had the dimension of 48.80 nm x 42.13 nm x 20.53 nm.
Conclusion:
AFM provide a new means for morphological investigation of the biomacromolecule at the nanometer scale in physiological conditions, and SPA-G can be utilized for in situ labeling of the neuronal membrane receptors.
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