Suchergebnisse

The current state of the problem of folding proteins and other biopolymers is discussed. The
concept of a multidimensional potential energy surface and a free energy surface for linear
polymers is detailed, taking into account the topology of the configuration space and the
presence of symmetry elements with respect to the permutation of identical monomer units. The
presence of kinematic bonds for conformational movements in a viscous medium leads to a
tendency to form helical structures of linear polymers. The dynamic effects of viscosity also lead
to an almost uniform distribution of energy dissipation rates over the chain nodes. The
combination of potential energy surface topography and viscosity effects provides a physical
basis for the development of the theory of folding in the direction of interpreting various
experimental observations and elucidating the principles for the formation of an amino acid
code for 3D protein structures. The relationship between the denaturation temperature of the
folded state of the biopolymer and the energy of non-valent interactions between monomers in
the chain is analyzed.

This paper demonstrates an example of a successful upgrade of a JEOL JEM-2100 analytical
transmission electron microscope to a low-resolution cryo-electron microscope designed for
routine tasks of sample preparation and quality evaluation. As a result of the upgrade, the instrument allows the subnanometer resolution of protein molecule reconstructions (within 8 Å).
The influence of graphene and amorphous carbon support films to prevent the effect of preferred
orientation of protein particles in the frozen sample is discussed.

The study involved the fabrication of films with different roughness and scaffolds made of
poly(3-hydroxybutyrate) using various methods. Chaotic and oriented scaffolds with varying
fiber thickness were obtained through the electrospinning method, depending on the polymer
concentration and electrospinning parameters. Films with different surface roughness were
obtained using spin coating and self-assembly methods. It was demonstrated that the varying
microstructure of the surface does not affect the growth of mesenchymal stem cells over the
course of a week; however, it does influence the morphology of the adhered cells.