||It is becoming increasingly evident that dynamics is a key feature of
the biological functions of macromolecules. Proteins are by no means
static objects and exhibit a variable degree of structural flexibility.
Recent developments of single-molecule detection techniques now make
possible modeling protein dynamics by resolving the relevant physical
interactions directly from experimental measurements. We recently
provided the first example of such innovative strategy by analyzing an
ensemble of three-dimensional cryo-electron tomography (cryo-ET)
individual reconstructions of Immunoglobulin G (IgG), and consequently
building up a mechanical model of the protein. This
experimentally-based model was then employed to inspect by means of
Brownian dynamics simulations the entire pathway of a typical
IgG-antigen reaction chain.