Protein engineering and single molecule fluorescence: combined to study new folding and binding mechanisms

The general use of the classical view in protein folding for an scenario with two species, folded and unfolded, separated by a high energy barrier (named two-state behavior) has been challenged in recent years. New folding and binding behaviors have been found, where different degrees of cooperativity separate intrinsically disorded proteins (around 30% of the total proteome shows large disordered sequences in eukaryotes), proteins without folding energy barrier (downhill behavior), metamorphic proteins from more rigid molecules with two-state behavior. The new protein behaviors represent an important part of the total proteome and their study will complete our understanding about how proteins adapt to different activities and conditions. In this talk I will show the application of protein engineering and single molecule fluorescence to study a downhill folding protein and a designed metamorphic protein, also illustrating the possibilities of these techniques to study similar systems. Moreover, I will explain future plans for the functionalization of designed systems using single molecule fluorescence to study folding, oligomerization and binding.