Analysis of flexible systems

Pau Bernadó

Small-angle X-ray Scattering (SAXS) is nowadays a well established method to structurally characterize biomolecules and macromolecular complexes in solution. Most common modelling strategies of SAXS data relay on the presence of a single family of particles in solution with an identical 3D structure. However, there are very relevant biological systems where this approximation is not valid. Intrinsically Disordered Proteins (IDPs) are an example of this situation. In IDPs, an astronomical number of conformations in fast exchange coexists is solution. For these cases traditional approaches are not longer valid and new modelling methodologies are required. Two different methods, the Ensemble Optimization Method (EOM) and the Minimal Ensemble Search (MES), have been recently developed for the quantitative interpretation of SAXS data of flexible biomolecules in terms of structure and dynamics.

In this talk the relevance of protein dynamics and how SAXS can help in its characterization will be presented. The importance of the detection of protein dynamics in order to avoid structural aliasing will be stressed. Additionally, the EOM will be presented with especial emphasis on the advantages, requirements and limitations for its usage. Several examples will be given to exemplify the concepts provided along the presentation.

Date/time: Friday, 29 October, 14:30