Date: Mon, August 21, 13:30-15:30
Place: Room Dw601, D Block, IIS, The University of Tokyo
Invited Speaker: Prof. Igor Mezic
                 (University of California, Santa Barbara)

Title: Biomolecules as nonlinear oscillators: Life-enabling dynamics

Abstract:
We present a study of complex biomolecules from the perspective of 
nonlinear dynamical systems theory. The basic - so-called minimalist - 
models used in molecular dynamics consist of a Hamiltonian part that 
captures the internal interactions among the atoms the molecule consists 
of,  and viscous and stochastic interactions with the surrounding 
solvent. The question of particular interest is that of switching from 
one conformed configuration of a biomolecule to another. In fact, 
understanding the mechanism of fast transitions between conformed states 
of large biomolecules is  central to reconciling the dichotomy between 
the relatively high speed of metabolic processess and slow (random-walk 
based) estimates on the speed of biomolecular processess. Here we 
utilize the dynamical systems approach to suggest that the reduced time 
of transition between different conformations is due to features of the 
dynamics of molecules that are a consequence of their structural 
features. Long-range and local effects both play a role.
Long-range  molecular forces account for the robustness of final states 
and nonlinear resonant processes that channel localized, bounded 
disturbances into  collective, modal motions. Local interconnecions 
provide fast transition dynamics.  We also present some experimental 
evidence of effect of resonance in conformational transitions.