[Design of a mathematical model of the formation of erythrocyte shape as an autowave process]. / K postroeniiu matematicheskoi modeli obrazovaniia form éritrotsita kak avtovolnovogo protsessa.

The phenomenological model of T. Teorell's "biomembrane generator" underlies the mathematical model of erythrocyte forms as an autowave process. For a distributed system the model is formulated as a differential equation of the second order in partial derivatives with a small parameter. It is stated that a substantial thing in the model is the presence of mass-transfer through a pore membrane determined by its electrostatic and hydrostatic permeabilities, as well as the fact that mass-transfer through the membrane results in a non-uniform distribution of the liquid current through it. It is suggested that as a consequence of this process there appears mechanical instability of the spherical membrane, which is the cause of the autowave process. Due to the membrane elasticity this process can be compared with the movement of "tank caterpillar".

[Asymptotic solution of the model of the erythrocyte shape as an autowave process]. / Asimptoticheskoe reshenie modeli form éritrotsita kak avtovolnovogo protsessa.

An asymptotic solution was plotted for a model of erythrocyte forms assuming that the biomembrane is anisotropic and of "small" thickness. This leads to small non-linearity and low diffusion, therefore the solution is unrelaxational. The model was investigated qualitatively assuming that the liquid current directed inside the spheric membrane induces its "distension", while that directed outside-its "crumpling". In the spherical system of coordinates the lines of solution level at theta = const are circumferences, while at phi-const-trochoids (Pascal coil, for example). Trochoids rotation areas show stomacyte and discocyte forms. Several hypotheses based on the analysis performed are advanced.

Effects of mutual influence of photoinduced electron transitions and slow structural rearrangements in bacterial photosynthetic reaction centers.

We describe the phenomenon of light-induced structural transformations in the reaction centers (RC) of photosynthetic bacteria which makes self-regulation of the RC charge separation efficiency possible. The nature of the effect is that the light-driven electron transfer (ET) between the RC redox-cofactors causes structural changes in the protein-cofactors system and this in turn affects the ET kinetics. If the electron-conformation interaction is strong enough, then such self-regulation gives birth to a new RC conformational state of enhanced charge separation efficiency. We show experimental results of stationary and kinetic absorbance change characteristics under different photoexcitation conditions, indicating structural rearrangements on a rather long (minutes) time scale, mainly within the secondary acceptor binding pocket. To simplify the description, in constructing a theory of structure-function reorganization in the RC we employ the adiabatic approach. Final expressions enable us to make qualitative comparison with experimentally observed kinetics of the fast and slow stages of 'free' and 'structurally controlled' electron relaxation, respectively.