SAXS versus FRET: A Matter of Heterogeneity?

Determining how conformational properties of unfolded proteins vary as a function of denaturant concentration has important implications for understanding the early stages of protein folding, and for our understanding of protein-solvent interactions. Upon dilution from a high concentration of denaturant into native conditions, does an unfolded protein undergo collapse first followed by folding, or does the chain remain expanded before folding and collapse occur concomitantly? The global dimensions of a protein are captured by its radius of gyration (Rg), meaning that, in principle, this question should be simple to answer by measuring Rg as a function of denaturant concentration.

http://ift.tt/2uMyni0