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Resolving Spatial Conformations of Immuno-Proteins with Cryo-Atomic Force Microscopy (Cryo-Afm)

Published online by Cambridge University Press:  02 July 2020

Zhifeng Shaon  and
Sitong Sheng
Zhifeng Shaon
Affiliation:
Departments of Molecular Physiology & Biological Physics, Box 449, Charlottesville, VA22908 Physics, University of Virginia, Charlottesville, VA22908
Sitong Sheng
Affiliation:
Departments of Molecular Physiology & Biological Physics, Box 449, Charlottesville, VA22908
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Extract

A major advantage of atomic force microscopy (AFM) is its intrinsic high contrast, owing to its extremely high sensitivity to height variations. For clean, flat specimens, high-resolution images of a variety of bio-molecules have been obtained, demonstrating the usefulness of AFM in structural biology. However, for large molecular complexes, the effectiveness of AFM is seriously limited, partly owing to the excessive deformation induced by the probe force exerted on the specimen. To overcome this difficulty, we have developed a cryo-AFM, operated under liquid nitrogen vapor at a temperature only a few degrees above 77K. In this system, specimen or tip contamination is significantly reduced, and the resolution achieved with isolated macromolecules is generally higher than that obtainable at room temperature with AFM. Therefore, cryo-AFM has been proven to be a worthy alternative for conventional electron microscopy (EM) with the potential of higher resolution without image averaging.

A particularly fruitful application of cryo-AFM is the study of the spatial structure of several immuno-proteins, where the 3D surface topology of the molecule has been obtained.

Type
Biological Applications of Scanning Probe Microscopies
Information
Microscopy and Microanalysis , Volume 5 , Issue S2: Proceedings: Microscopy & Microanalysis '99, Microscopy Society of America 57th Annual Meeting, Microbeam Analysis Society 33rd Annual Meeting, Portland, Oregon August 1-5, 1999 , August 1999 , pp. 1008 - 1009
Copyright
Copyright © Microscopy Society of America

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