CIMMS Seminar: Water Field Dynamics in the Vicinity of Proteins

Dr. Tamiki Komatsuzaki, Kobe University,  Japan
Department of Earth and Planetary Sciences

The Langevin formulation in nonequilibrium statistical mechanics has been one of the most utilized methods in describing complex dynamics of biomolecules in solution. This is based on an implicit assumption of the existence of separable time scales between the global dynamics of biomolecules and the surrounding solvents. However, recently, it was revealed for human Lysozyme in solution [1] that the rotational diffusion of local dipole field, which is defined as a short time ensemble average of the dipole moment vectors of many individual water molecules at a solvent site through which they pass or visit, has dynamical memory up to 70 times longer than the rotational relaxation of the individual water molecules in the vicinity of human Lysozyme. This indicates that the time separability required for validating the Langevin formulation does not necessarily hold and the water molecules may not necessarily retard the protein motions as "friction". We will overview their recent research and present our recent analyses on the  field dynamics of water molecules in the vicinity of polyalanine and other protein systems.  

[1] J. Higo et al. Proc. Natl. Acad. Sci. USA, 98, 5961-5964 (2001)
[2] T. Yokomizo, S. Yagihara and J. Higo, Chem. Phys. Lett. 374, 453 (2003)


NOTE:
Following this talk, there will be other talks and discussions on Molecular Dynamics from 2-6 PM in the CDS Library.  see http://www.cimms.caltech.edu/seminars_special/molecular_dynamics.html