Structural hierarchy of several proteins observed by wide-angle solution scattering

In the present study using a high-intensity X-ray beam from a third-generation synchrotron radiation source, it is demonstrated that a wide-angle X-ray scattering (WAXS) profile from several globular proteins in solution can reflect not only the overall structures (∼300 Å distance resolution) but also intramolecular structures ranging to secondary structures (∼2.5 Å distance resolution). The proteins treated in the present experiments are classified as different types of structure categories, namely, as all-α, all-β and α + β proteins. Here the full-range experimental scattering curves are compared with the theoretical curves, suggesting a further availability of the SR-WAXS method for studies of structure hierarchy and the function of proteins in solutions.