[Differences in spatial structures of the influenza virus M1 protein in crystal, solution and virion].

Spatial structure of the influenza virus A/Puerto Rico/8/34 (PR8, subtype H1N1) M1 protein in a solution and composition of the virion was studied by tritium planigraphy technique. The special algorithm for modeling of the spatial structure is used to simulate the experiment, as well as a set of algorithms predicting secondary structure and disordered regions in proteins. Tertiary structures were refined using the program Rosetta. To compare the structures in solution and in virion, also used the X-ray diffraction data for NM-domain. The main difference between protein structure in solution and crystal is observed in the contact region of N- and M-domains, which are more densely packed in the crystalline state. Locations include the maximum label is almost identical to the unstructured regions of proteins predicted by bioinformatics analysis. These areas are concentrated in the C-domain and in the loop regions between the M-, N-, and C-domains. Analytical centrifugation and dynamic laser light scattering confirm data of tritium planigraphy. Anomalous hydrodynamic size, and low structuring of the M1 protein in solution were found. The multifunctionality of protein in the cell appears to be associated with its plastic tertiary structure, which provides at the expense of unstructured regions of contact with various molecules-partners.

[Modeling of protein spatial structure using tritium planigraphy].

The results of proteins spatial structure modeling using the tritium planigraphy technique are presented. The knowledge of three-dimensional structure of macromolecules is extremely necessary to understand the basic mechanisms of interaction in biological systems and complex technological processes. Known limitations of the X-ray analysis (crystal state) and NMR (molecular weight) make it necessary to seek new approaches to modeling the spatial structure of proteins. Semiempirical tritium planigraphy technique is one of these approaches. The method is based on the bombardment of the object by beam of hot tritium atoms (E(at) > or = 0.3 eV) and a computer simulation experiment. On the example of proteins of the different structural classes we set that by using this integrated approach can be obtained by three-dimensional model of the structure, well consistent with the data of X-ray analysis. An important factor is a sequence search of contacts between secondary structure elements: the best fit model with the native structure is achieved by assembling the elements of a vector in the sequence from the N- to C-terminus of the polypeptide chain.

Spatiotemporal period doubling in a nonlinear interferometer with distributed optical feedback.

A single-pass nonlinear interferometer with feedback field rotation is considered. Increasing feedback gain results in excitation of spatial subharmonics that distort optical reverberators, which are basic output patterns of the system. Features of the period-doubling process depend on the number of the reverberator's petals. A new spatiotemporal effect is observed: A basic structure with an odd number of petals is perturbed not by a static subharmonic but by a rotating wave.