Download republique française - Laboratoire Léon Brillouin (LLB)

RÉPUBLIQUE FRANÇAISE
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE - COMMISSARIAT A L'ÉNERGIE ATOMIQUE
LABORATOIRE LÉON BRILLOUIN
 33 (0) 1.69.08.52.41
Séminaire Physico-chimie & Biologie
Vendredi, 24 Juin 2005
11 :00
Bât. 563 - salle 15
A Molecular View of Hydration Dynamics Near a Model Peptide
Daniela Russo
OGG INFM/CRS SOFT Grenoble (Fr)
New experimental techniques such as wide-angle neutron and quasi-elastic neutron
scattering, third generation x-ray synchrotrons, accompanied by interpretation and analysis using
molecular dynamics, have emerged for characterizing the structure and dynamics of complicated
solvent environments near biological macromolecules and interfaces. How these solvents and cosolvents influence protein function or mediate protein-protein interactions have numerous
connections to our understanding of the fundamental aspects of cellular function, self-assembly in
bio-inspired nanomaterials and in high-throughput protein technologies and bioprocessing.
Unfortunately, experimental studies of solvent influences on self-assembly and organization have
been relatively rare and not systematic. One of the principal limitations is that techniques able to
investigate solution organization or solvation dynamics give highly averaged information over all
different kinds of molecular interactions, with a variety of time scales and length scales. To address
these limitations, we have developed a well-defined model system based on amino acid monomers
in solution that permits us to dissect interactions over nanometer length scales and picosecond
time scales. This model system investigates the evolution of solution structure and dynamics by
varying amino acid concentration, thereby modeling how the solvent behaves under dissociating
conditions when the local concentration of amino acids is relatively dilute, while more concentrated
solutions describe the consequences of hydration near assembled solute states or at proteinprotein interfaces when the local concentration of amino acids is very high. In this talk I will place
our QENS measurements on model biological solutes in the context of other spectroscopic
techniques, and provide both confirming as well as complementary dynamical information that
attempts to give a unifying molecular view of hydration dynamics signatures near peptides and
proteins.
Laboratoire Léon Brillouin - CEA/Saclay - F - 91191 GIF-SUR-YVETTE
Télécopieur 33 (0) 1.69.08.82.61