Ultraviolet resonance Raman spectroscopy of the refolding and unfolding reactions of the protein Barstar

Data de Início: 
quinta-feira, 14 Março, 2019 - 16:00
Prof. Dr. Erix A. Milán-Garcés
Auditório Abrahão de Moraes do IFUSP


Ultraviolet resonance Raman spectroscopy of the refolding and unfolding reactions of the protein Barstar

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. 


Sobre o Palestrante: Erix A. Milán-Garcés received a B.Sc in Physics from Universidad de Oriente (Santiago de Cuba, Cuba) and a Ph.D from National Centre for Biological Sciences (NCBS), TIFR (Bangalore, India) with Prof. M. Puranik. During his Ph.D he worked on the application of Raman spectroscopy to study excited-state dynamics and protein folding and unfolding. Then, he worked as a Bridging Postdoctoral Fellow with Prof. S. Gosavi also at NCBS. From 2015 till January 2019 he was a postdoc at Universidade Federal de Juiz de Fora (UFJF) in the groups of Prof. G. F. S. Andrade (Department of Chemistry), Prof. R. C. N. Melo (Institute of Biological Sciences) and F. Sato (Department of Physics). He taught Advanced Calculus and General Physics at Universidad de Granma (Cuba) and Universidad de Oriente (Santiago de Cuba) respectively. He also taught the course “Optical spectroscopy methods in Biology” at (Institute of Biological Sciences, UFJF). His research interests include the application of Raman spectroscopy in combination with other optical spectroscopy methods to study the structure and dynamics of biomolecules in solution and in cells


Palavras-Chaves: UV Raman spectroscopy, protein folding, CH-π interactions