Erix Alexander Milán Garcés

Título : 
Ultraviolet resonance Raman spectroscopy of the refolding and unfolding reactions of the protein Barstar
Resumo : 
Ultraviolet resonance Raman (UVRR) spectroscopy is a powerful technique to monitor the folding and unfolding equilibrium and kinetics reactions in of proteins. In this talk I will show some results of the application of UVRR to study the salt-induced refolding and denaturant-induced equilibrium reactions of a single tryptophan (Trp53) mutant of protein barstar. During the refolding of the protein it was found that even for lower salt concentrations the formation of the CH-π interactions as well as the increase on the packing of the core occurs. Based on the results a scheme with the steps of the equilibrium refolding reaction of barstar has been proposed. On the other hand, the changes in the UVRR spectral characteristics of Trp53 during the equilibrium unfolding of barstar suggest that the core change in a continuous manner. Due to the continuous expansion of the core, the CH-π and packing interactions also become weaker which allow increasing in the mobility of Trp53 side chain. An increase in the conformational heterogeneity of the protein during unfolding is also observed. I will also introduce some of the ideas I would like to work at the IFUSP. They are related to the application of resonance Raman spectroscopy and Surface-enhanced Raman scattering to study membrane protein folding, protein aggregation and DNA-protein interactions.