Integral approach to biomacromolecular structure by analytical-ultracentrifugation and small-angle scattering.

Currently, a sample for small-angle scattering (SAS) is usually highly purified and looks monodispersed: The Guinier plot of its SAS intensity shows a fine straight line. However, it could include the slight aggregates which make the experimental SAS profile different from the monodispersed one. A concerted method with analytical-ultracentrifugation (AUC) and SAS, named as AUC-SAS, offers the precise scattering intensity of a concerned biomacromolecule in solution even with aggregates as well that of a complex under an association-dissociation equilibrium. AUC-SAS overcomes an aggregation problem which has been an obstacle for SAS analysis and, furthermore, has a potential to lead to a structural analysis for a general multi-component system. Ken Morishima et al. integrate small-angle scattering (SAS) with analytical-ultracentrifugation (AUC) to analyze the scattering intensity of biomacromolecules in solution. Their new approach allows to correct for the aggregation effect and can be applied to multi-component systems.