Nanoscale Dynamics of Protein Assembly Networks in Supersaturated Solutions

Proteins in solution are conventionally considered macromolecules. Dynamic microscopic structures in supersaturated protein solutions have received increasing attention in the study of protein crystallisation and the formation of misfolded aggregates. Here, we present a method for observing rotational dynamic structures that can detect the interaction of nanoscale lysozyme protein networks via diffracted X-ray tracking (DXT). Our DXT analysis demonstrated that the rearrangement behaviours of lysozyme networks or clusters, which are driven by local density and concentration fluctuations, generate force fields on the femtonewton to attonewton (fN – aN) scale. This quantitative parameter was previously observed in our experiments on supersaturated inorganic solutions. This commonality provides a way to clarify the solution structures of a variety of supersaturated solutions as well as to control nucleation and crystallisation in supersaturated solutions.