SMALL-ANGLE X-RAY SCATTERING APPLIED TO PROTEINS IN SOLUTION

This chapter discusses some of the most-used methods to analyze in-solution small-angle X-ray scattering (SAXS or SAS) data, with special attention on the protein SAS study. The initial data analysis by means of some independent-model procedures can be realized directly from a scattering curve, giving important information in respect to protein structural parameters as radius of gyration, its maximum dimension, and giving reasonable information on the protein folding conformation, molecular weight, and multimeric state. The methods discussed are Kratky's representation, Guinier's law, and Porod's invariant. The chapter presents an experimental SAXS data for protein old yellow enzyme (OYE), and replication factor C (RFC) protein complex. It also talks about an analysis of protein bovine serum albumin (BSA), under the influence of denaturing agents, protein interaction and aggregation.