Fluorescence, Circular Dichroism and Mass Spectrometry as Tools to Study Virus Structure

Fluorescence and circular dichroism, as analytical spectroscopic techniques, and mass spectrometry, as an analytical tool to determine molecular mass, are important biophysical methods in structural virology. Although they do not provide atomic or near-atomic details as cryogenic electron microscopy, X-ray crystallography or nuclear magnetic resonance spectroscopy can, they do deliver important insights into virus particle composition, structure, conformational stability and dynamics, assembly and maturation and interactions with other viral and cellular biomolecules. They can also be used to investigate the molecular determinants of virus particle structure and properties and the changes induced in them by external factors. In this chapter, the physical foundations of these three techniques will be described, alongside examples demonstrating their contribution in understanding the structure and physicochemical properties of virus particles.