Analytical ultracentrifugation combined with X-ray and neutron scattering: Experiment and modelling.

摘要: Analytical ultracentrifugation and solution scattering provide different multi-parameter structural compositional information on proteins. The joint application of the two methods supplements high resolution studies by crystallography NMR. We summarise procedures required to obtain equivalent X-ray neutron data. constrained modelling data is important confirm experimental analysis yields families best-fit molecular models for comparison with NMR structures. This described in terms starting models, their conformational randomisation trial-and-error fits, identification final models. Seven applications these are illustrate current state-of-the-art. These include determination antibody structures (the human IgG4 subclass, oligomeric forms IgA its secretory component), complement proteins innate immunity (Factor H C3/C3u) interactions macromolecular ligands (C-reactive protein), anionic polysaccharides (heparin). Complementary features experiments facilitate an improved understanding crystal (illustrated C3/C3u, C-reactive protein heparin). If a large or complex cannot be crystallised, ultracentrifugation-scattering approach provides means overall structure.