Properties and symmetry of the solid cluster phase of protein

To date, only one solid crystalline form of protein has been discovered and studied. At the same time, we have experimentally found that the solid protein phase may have fundamentally different properties, as well as various types and scales of symmetry, depending on condensation conditions in the water-protein system. The key issue here is the condensation kinetics. For example, in an open system under the equilibrium conditions (low process rate), the equilibrium long-range crystalline protein lattice forms at the microlevel. In a nonequilibrium (high process rate) protein-water system, an autowave process with nonlinear irregular dynamics is established and a polyfilm solid phase with a set of three-dimensional dissipative nanostructures occurs. The type and scale of symmetry change. The crystal order at the microlevel disappears, and the material becomes amorphous. A new allotropic modification of the solid nonequilibrium protein film arises. This modification has the highly ordered (on the nano-to macroscale) superlattice with straight, helical, chiral, mirror, or rotation symmetry. This kind of protein has been identified both in vitro and in vivo and has been called “protos.”.