Structural and Mechanical Characterization of Viruses with AFM

Area of Science:

• Biophysics
• Nanotechnology
• Microscopy

Background:

• Microscopy uses probes like photons or electrons to characterize small objects.
• Atomic force microscopy (AFM) employs a nanometric tip on a cantilever to 'feel' specimens, enabling nanoscale imaging.

Purpose of the Study:

• To review methods for adsorbing protein shells onto surfaces for AFM analysis.
• To describe various AFM approaches for studying individual protein cages.
• To detail AFM's capability in characterizing physicochemical and mechanical properties of protein shells.

Main Methods:

• Atomic force microscopy (AFM) for high-resolution imaging of protein shells in liquid.
• Spectroscopic methodologies using AFM to extract physical information (mechanical, electrostatic properties).
• Combined AFM and fluorescence techniques to monitor dynamic processes like genome release.

Main Results:

• AFM enables nanometric resolution imaging of individual protein shells, including viruses, in aqueous environments.
• AFM allows for the manipulation and detailed characterization of single protein cages.
• Integrated AFM and fluorescence methods can track genome release from viral shells under mechanical stress.

Conclusions:

• AFM is a versatile tool for nanoscale imaging, manipulation, and physical property characterization of protein shells.
• The combination of AFM with other techniques like fluorescence provides powerful insights into complex biological processes at the single-molecule level.
• This chapter provides a comprehensive overview of AFM applications in studying protein shell mechanics and dynamics.