Belgrade : Institute of molecular genetics and genetic engineering
Abstract
Molecular chains (such as protein chains with alpha-helical secondary structure, DNA and
RNA molecules) can play the role of “bridges” for the highly efficient transfer of various
types of submolecular excitations (vibron excitations or electrons) over very long distances
(comparable to the length of the molecular chain itself). In the case when this process
takes place in living cells, the biomolecule is placed in an environment where it is usually
in thermodynamic equilibrium with the “heat bath”. As a result, the structural elements of
the molecular chain perform mechanical oscillations. In the general case, such mechanical
oscillations disrupt the ability of the molecular bridge to transfer the excitation over a
longer distance.
On the other side, by interacting with the thermal oscillations of the structure, excitations
injected into the molecule may be trapped and can form a stable self-trapped (polaronlike)
state. Such quasiparticles can move through the structure with minimal energy
loss. In this way, the high efficiency of energy and charge transport in living cells can be
explained. However, the properties of the possibly formed polaron quasiparticle must also
be affected by the presence of the donor molecule.
Here, we have discussed the mechanism of excitation transfer from a molecular structure
(donor molecule) to the molecular chain. The presence of the donor structure and the
temperature influence on the energy of the self-trapped excitation were considered in the
dependence of the basic energy parameters of the molecular bridge. The obtained results
indicate the possibility of the formation of two types of self-trapped states: a quasi-free
excitation, which can easily move through the molecular bridge, and a localized, practically
immobile excitation, which is similar to a non-adiabatic polaron quasiparticle.Book of abstract: 4th Belgrade Bioinformatics Conference, June 19-23, 202
