Transcript AVVISO DI SEMINARIO Prof. Frans Mulder Protein dynamics and

 AVVISO DI SEMINARIO
Giovedì 4 febbraio ore 15,00
nell'Aula Seminari del Dipartimento di
Scienze e Tecnologie Chimiche, la
Prof. Frans Mulder
Interdisciplinary Nanoscience Center (iNANO),
Department of Chemistry,
Aarhus University
Terrà un seminario dal titolo:
Protein dynamics and the protein glass
transition
Proponente: Dott. Marco Sette
web: http://www.stc.uniroma2.it/
e.mail: [email protected] Abstract
Mössbauer and neutron scattering studies of proteins invariably show a strong increase in protein
dynamics above temperatures of around 220 K. It has long been believed that this onset of
anharmonic protein dynamics is due to a phase transition in the surrounding water molecules, such
as that observed in glasses. It has consequently been concluded that 'the protein is slaved to the
solvent'.
I will challenge this notion, using temperature-dependent NMR spectroscopy. NMR spectroscopy is
uniquely capable of measuring a protein's motions at atomic resolution, and on time scales from
picoseconds to hours. I will show that we are able to measure the extent of flexibility and dynamics
in individual amino acid side chains, and demonstrate that changes in nanosecond timescale
dynamics in the protein are directly responsible for the 'protein glass transition', irrespective of a
phase transition in the surrounding water. The coincidence observed for dynamic transitions in the
protein and water constituent parts of other systems supports a view where protein and water
dynamics are strongly coupled. Our study suggests that neither can be assigned as master or slave.
web: http://www.stc.uniroma2.it/
e.mail: [email protected]