SAXS: biological molecules
Small angle scattering (SAXS) and related diffraction techniques are used to study non-crystalline biological macromolecular systems, including proteins in solution and biological fibers. The information content in SAXS is of relatively low-resolution because these biological systems usually randomly oriented in solution or only partially ordered. SAXS techniques can often study specimens under conditions that are similar to the physiological environment. The ease of controlling sample conditions is also an advantage for physical and chemical characterization. Time-resolved studies, which follow the response of a biological system to a perturbation in the physical or chemical environment, are also possible with SAXS.SAXS also compliments other techniques in structural biology. For instance, a solution scattering curve can be readily calculated using a set of atomic coordinates derived from macromolecular crystallography, providing a means of comparing solution structures with crystal structures. Structural changes induced by ligand binding, or changes in other chemical or physical environment, can be monitored using solution scattering and interpreted based on high-resolution structures derived from other techniques. Solution scattering can help model a large molecular complex whose over-all structure is unknown but where the structures of individual components are available.
Rigaku offers a choice of SAXS solutions, from the dedicated 2D-SAXS capable S-MAX3000 to the powerful and flexible Ultima IV and the exceptionally easy-to-use SmartLab®.