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Objectives. Numerous studies of biosystems indicate the distinct role of quasi-one-dimensional molecular structures in the transport of energy, charges, and information. Of particular interest are the studies on the collective dynamics of quasi-one-dimensional lateral structures in liquid crystalline membranes and the possibility of local excitation transfer through such structures. In this paper, we developed a model for the collective dynamics of quasi-one-dimensional domain structures in lipid bilayers interacting with the environment. The objective is to study the mechanisms of the directed energy transport in liquid crystalline lipid membranes.Methods. In this paper, the percolation domain structures formed as a result of phase separation in multicomponent lipid membranes are considered to be quasi-one-dimensional domain structures. The model distinguishes two subsystems interacting with each other and differing in their structural and dynamic properties, i.e., the membrane surface formed by polar groups of lipid molecules and the internal hydrophilic region of the membrane formed by acyl chains of lipids. The acyl chain subsystem is simulated using the Ginzburg-Landau Hamiltonian which considers the dependence of its dynamics on temperature close to the lipid melting phase transition temperature Tc.Results. Analysis of dynamic states has shown that elastic excitations moving at constant rate in the form of solitons may exist near temperatures Tc in the considered quasi-one-dimensional domain structures. In addition, motion of the elastic excitation region (kink) along domain structures in the acyl chain region causes the formation of acoustic soliton, i.e., the compression region in the polar group subsystem moving in concert with the kink displacement. The soliton localization region covers about 10 molecules and depends significantly on the interaction parameter of the polar group and acyl chain subsystems. Soliton moves at a subsonic speed determined, in particular, by the magnitude of an external force.Conclusions. The model developed in this paper shows that liquid crystalline domain structures in lipid membranes exhibit properties of active media, wherein the formation and displacement of localized elastic excitations on macroscopic spatial and temporal scales may occur. The proposed molecular mechanism of the soliton transport along quasi-one-dimensional domain structures may be used for describing the directed energy transfer along lateral domain channels in biomembranes and the cooperative functioning of the membrane bioenergetic and receptor complexes.

The article discusses the features of the radiation of ultrafast point clusters of charged particles moving uniformly near a gyrotropic medium interface. It is shown that some types of electromagnetic radiation – transient and/or Cherenkov radiation – have the characteristics of superchiral fields. Therefore, they can be effectively used to study chiral structures (for example, to detect circular dichroism, the frequency characteristics of refractive indices), various materials, including biomaterials. Ultrafast (relativistic) particles can serve as a «tool» not only for studying the structure of various materials. They can also be used as «generators» of quasiparticles that determine the «dynamic» properties of the materials under study, as well as the features of their interaction with radiation of various nature and response to external influences. In this paper, some types of circularly polarized EM waves propagating in optically active (magnetoactive, naturally active, gyrotropic, and chiral) media are considered. Using the generalized reciprocity theorem for media characterized by the Hermitian permittivity tensor, we consider the transient and Cherenkov radiation excited by a uniformly moving bunch of charged particles when it crosses (or moves along) the interface of media, one of which is an optically active gyrotropic medium. It is shown that the superchiral electromagnetic fields of the transition and Cherenkov radiation of dipoles can serve as a source of chiral collective excitations in magnetoactive and naturally active media. The investigated mechanisms of interaction of electromagnetic radiation with chiral materials (structures and media) are one of the possible physical approaches to solving the problem of the chiral purity of the biosphere and to elucidate the factor of deracemization of the organic primeval environment. A new hypothesis is presented, suggesting that ultra-high-speed clumps of charged particles of cosmic origin can cause deracemization of the prebiosphere.

The possibility of the electrosoliton formation in α-helical proteins which represents a localized state of an extra electron bound with the deformation region of the α-helix arising due to the electron interaction with chain of peptide groups is investigated in a quasiclassical approximation. Two possible mechanisms of the formation of collective dynamic modes in the form of Fröhlich collective mode and Davydov soliton were previously suggested by the authors. In this paper, we developed a unified quantum-mechanics approach to describe conditions of the formation of the Fröhlich vibronic state and Davydov soliton in α-helical protein molecules interacting with the environment. The concept of "soliton" is used not only in the strict mathematical sense, i.e. in the case of completely integrable Hamiltonian systems, but also to describe dynamically stable, nonlinear collective structures. Davydov solitons are stable due to a small probability of the dissipation of its energy into thermal energy which provides a high efficiency of soliton transport of energy, charges, and conformation changes in biosystems at a physiological temperature of 310 K.Electrosolitons can be formed if the value of electron–phonon interaction (EPI) parameter exceeds a certain threshold. One of the most important characteristics of the electrosoliton’s state is the coupling energy of a quasi-particle (exciton or electron) with molecular chain deformation, which also determines the soliton stability. Dynamic equations describing the motion of a one-dimensional electrosoliton in the continuum approximation are a self-consistent system which includes the time-dependent Schrödinger equation with a deformation potential and an inhomogeneous linear wave equation for this potential. This system, known as the Zakharov system, has significance in physics and, generally, describes the nonlinear interaction of two physical subsystems: fast and slow. Zakharov equations have a well-known soliton solution in the hyperbolic secant form, describing the envelope profile of the high-frequency vibrations of a fast subsystem, which can propagate with any subsonic velocity. The suggested mechanism of emergent of macroscopic dissipative structures in the form of electrosolitons in α-helical proteins is discussed in connection with recent experimental data on long-lived collective protein excitation in the terahertz frequency region.

Continuous energy supply, a necessary condition for life, excites a state far from thermodynamic equilibrium, in particular coherent electric polar vibrations depending on water ordering in the cell. The collective, low-frequency vibrational excitations in protein macromolecules in the terahertz frequency region are suggested to orchestrate many protein processes such as enzymatic activity, electron/energy transport, conformation transitions and others. The most significant type of excitations is long-lived coherent vibronic modes and waves which are either spreading over large protein subdomains or being localised states. Two possible mechanisms of the formation of collective dynamic modes in the form of Fröhlich collective mode and Davydov soliton were previously suggested. We developed a unified quantum-mechanics approach to describe conditions of the formation of Fröhlich vibronic state and Davidov soliton in alphahelical protein molecules interacting with the environment. We distinguish three subsystems in the model, i.e., (i) oscillating peptide groups (PGs), interacting with (ii) the subsystem of side residuals of proteins, which in turn interacts with the environment (surrounding water), which is responsible for dissipation and fluctuation processes and modelled by a system of harmonic oscillators. It was shown that the equation of motion for dynamic variables of PG chain (phonon variables) can be transformed to the nonlinear Schrodinger equation for order parameters, which determines energy “pumping” due to protein interaction with a reservoir. Solution of the order parameter equation was shown to admit bifurcation into the solution corresponding to the formation of weak damped collective vibronic mode with growing amplitude. It was also shown that the solution corresponding to Davydov soliton can exist at certain boundary conditions in this bifurcation region. The suggested mechanism of emergent of macroscopic dissipative structures in the form of collective vibronic modes in proteins is discussed in connection with recent experimental data on long-lived collective protein excitation in the terahertz frequency region