Small Angle Neutron Scattering from Proteins in Solution

The study of biomolecules in solution is quite important in order to reproduce environmental conditions quite resembling those existing in-vivo. Small Angle Neutron Scattering (SANS) from proteins in solution provides information concerning size and shape, over a large length scale. Performance of SANS experiments on samples at different deuteration grades enables a deeper knowledge both of protein structure and of protein solvation shell. The chance to perform numerical simulation before carrying on a SANS experiment can lead the user to a wiser choice of the experiment preparation and greatly improve the structural resolution. A brief discussion about the scattering theory, isotopic substitution and thermodynamic equilibria between water and cosolvent molecules in the protein solvation shell, will be presented. This chapter will discuss theory and practical aspects with protein conditions in order to guide potential users to successfully apply SANS experiments to answer peculiar biological questions involving proteins in solution.