Speaker
Marco Pettini
(Aix-Marseille University)
Description
In the first part of this talk I will report about the
theoretical and experimental findings about the activation
of out-of-equilibrium collective oscillations of a
macromolecule as a classical phonon condensation phenomenon
[Phys. Rev. X 8, 031061 (2018)]. If a macromolecule is
modeled as an open system—that is, it is subjected to an
external energy supply and is in contact with a thermal bath
to dissipate the excess energy— the internal nonlinear
couplings among the normal modes make the system undergo a
nonequilibrium phase transition when the energy input rate
exceeds a threshold
value. This transition takes place between a state where the
energy is incoherently distributed among the normal modes
and a state where the input energy is channeled into the
lowest-frequency mode entailing a coherent oscillation of
the entire molecule. The experimental outcomes (obtained
with two independent setups and performed on a model
protein) are in very good qualitative agreement with the
theory and provide a proof of concept of which the most
significant implication is that, in compliance with another
theoretical prediction [Phys. Rev. E 91, 052710 (2015)], a
crucial prerequisite is fulfilled to excite intermolecular
long-range electrodynamic interactions. In turn, these
interactions could affect the biomolecular dynamics by
contributing to drive the high efficiency and rapidity of
mutual encounters of the partners of biochemical reactions
in living matter. In the second part of the talk I will
report on the outcomes of two other recent and independent
experiments clearly showing the activation of
long-range/long-distance electrodynamic interactions among
biomolecules (proteins) as a consequence of the activation
of out-of-equilibrium collective molecular oscillations. It
has been found that the model proteins used can mutually
attract at a distance as large as 1000 Angstroms, which is
by far larger than all the other intermolecular interactions
usually considered in action in living matter.
