Oxidative folding: Coupling conformational folding and disulfide formation

Abstract

Determining how a string of amino acid residues folds into the -biologically active protein conformation remains as one of the most important and challenging tasks in biology. Protein folding is usually a fast reaction in which transient intermediates in the folding pathway are short lived, highly dynamic, and very difficult to be trapped, isolated, and characterized. The technique of oxidative folding applied to study disulfide proteins overcomes some of these problems. During protein oxidative folding, the coupling between conformational folding and disulfide formation together with the possibility to selectively quench the progress of the oxidative reaction permits the isolation and further structural characterization of transient folding intermediates in atomic detail. With its unique chemistry and relatively slow kinetics of disulfide formation, the technique of oxidative folding has facilitated the detailed characterization of the folding pathways of an important number of disulfide-rich proteins. The results reveal a high degree of diversity of folding mechanisms, which are mainly manifested by the extent of heterogeneity and native-like structures of their intermediate ensembles. Overall, as we will discuss in this chapter, the study of disulfide-containing polypeptides has contributed significantly to our current knowledge on the molecular basis of protein folding. © 2011 Springer Science+Business Media, LLC.