Obtaining and Characteristic of Antibodies to Vibrio cholerae Protective Antigens Conjugated with Gold Nanoparticles.

Gold nanoparticle conjugates with Vibrio cholerae antigens were synthesized. The animals were immunized with the obtained conjugates. Rabbit polyclonal antibodies to the antigens were obtained, which showed high specific activity. On the model of white laboratory mice, the protective activity of conjugates of cholera antigens with nanoparticles during infection of vaccinated animals was evaluated using a commercial vaccine as a control. It was shown that in terms of immunogenicity, the created prototypes of cholera vaccine using gold nanoparticles as a carrier and adjuvant complied with the production regulations for the Russian national cholera chemical vaccine.

Effects of radiation damage in studies of protein-DNA complexes by cryo-EM.

Nucleic acids are responsible for the storage, transfer and realization of genetic information in the cell, which provides correct development and functioning of organisms. DNA interaction with ligands ensures the safety of this information. Over the past 10 years, advances in electron microscopy and image processing allowed to obtain the structures of key DNA-protein complexes with resolution below 4Å. However, radiation damage is a limiting factor to the potentially attainable resolution in cryo-EM. The prospect and limitations of studying protein-DNA complex interactions using cryo-electron microscopy are discussed here. We reviewed the ways to minimize radiation damage in biological specimens and the possibilities of using radiation damage (so-called 'bubblegrams') to obtain additional structural information.

[Structural studies of chromatin remodeling factors].

Changes of chromatin structure require participation of chromatin remodeling factors (CRFs), which are ATP-dependent multisubunit complexes that change the structure of the nucleosome without covalently modifying its components. CRFs act together with other protein factors to regulate the extent of chromatin condensation. Four CRF families are currently distinguished based on their structural and biochemical characteristics: SWI/SNF, ISWI, Mi-2/CHD, and SWR/INO80. X-ray diffraction analysis and electron microscopy are the main methods to obtain structural information about macromolecules. CRFs are difficult to obtain in crystal because of their large sizes and structural heterogeneity, and transmission electron microscopy (TEM) is mostly employed in their structural studies. The review considers all structures obtained for CRFs by TEM and discusses several models of CRF-nucleosome interactions.

[Molecular Dynamics of N- and C-terminal Interactions during Autoinhibition and Activation of Formin mDial].

With the method of molecular dynamics, pairs of amino acid residues have been identified on the surface of the interacting formin mDial domains: DID-DAD, which are responsible for the autoinhibition of formin, and the GTPase Rho-DID domain, and control activation. It was found that the most stable interactions are ionic interactions between Glu178 residue and Arg248 residue, as well as hydrophobic interactions between Thr175 and Phe247. The strongest interactions proved to be between the DID domain with Rho-GTPase. These interactions are mediated by specific triple ionic interactions between positively charged amino acid in Rho, and a triplet of amino acids in DID, consisting of two negatively charged amino acids, separated by one uncharged. Binding sites for Rho-GTPase and DAD partially overlap, but various amino acids on the DID participate in interactions with different domains. We discuss the possible conformational changes in formin domains during activation and inactivation.

[Assessment of Binding Properties of Actinomycin and Its Derivatives with DNA Molecule Using Molecular Dynamics Simulation Method].

Molecular dynamics simulation method was used to assess an influence of actinomycins (antibiotics used in chemotherapy for treatment of some oncology diseases) on DNA fragment elasticity. Also the efficiency of binding of actinomycin to DNA fragment was estimated. Energetic contributions of different substitutions of hydroxyl and amino-group to the phenoxazine ring of actinomycin were studied to analyze dynamic behavior and stability of antibiotic-DNA fragment complexes. Young modulus values were calculated for structures: DNA/DNA-actinomycin/DNA-7-hydroxyactinomycin/DNA-7-aminoactinomycin. Free energy calculations were performed for the formation of actinomycin- and two actinomycin analogues-DNA fragment complexes. Our results suggest that the inserted substitutions stabilize the structure of a DNA fragment via the formation of additional hydrogen bonds.

[The components of Francisella tularensis protective antigene complex].

The structural characteristics of Francisella tularensis protective antigene complex (PAC) were discussed. PAC is the water-soluble antigene of outer membranes F. Tularensis with sophisticated chemical nature. The molecular weight of PAC is 280 kD. It was found that PAC is composed of some immunoreactivity protein subunits with molecular weight from 81 to 19 kD, and 14-17 kD lipoprotein subunit. The stress proteins-chaperones (GroES, GroEL), outer membrane proteins (FTL_0617, OmpH), receptor proteins (EF Tu, Rp1L), bacterial enzymes (KatG, GAPDH), and lipopolysaccharide were identified in the PAC structure. Their presence determines the PAC high immunobiological activity.

[Evaluation of immunobiological activity of Francisella tularensis C-complex preparations as promising component of subunit vaccines].

Data on influence of Francisella tularensis C-complex preparations on formation of immunity against tularemia are presented. Study of cellular immunity characteristics as well as dynamics of antibody response was carried out on white mice and guinea pigs models. Absence of toxicity, pyrogenicity, and negative effects on immunocompetent cells in combination with protective activity points to possibility of use the C-complex as a component of a subunit vaccine.

[Anti-rabies immunoglobulin preparation based on F(ab')2 fragments].

Technology of manufacturing of new anti-rabies immunoglobulin preparation based on F(ab')2 fragments has been developed. This preparation is characterized by low reactogenicity, increased virus-neutralizing activity and stability.

[Lectin of Yersinia pestis vaccine strain EV and its immunological properties]. / Lektin vaktsinnogo shtamma Yersinia pestis EV i izuchenie ego immunobiologicheskikh svoistv.

As the result of the chromatographic separation of Y. pestis EV membrane proteins, a protein fraction with hemagglutinating activity was obtained. The isolated preparation was glycoprotein with a molecular weight of 22 kD, contained 16% of carbohydrates and exhibited thermolabile properties. The determination of the carbohydrate specificity of this glycoprotein revealed that it belonged to the class of lectins. Changes in the content of 11 corticosteroids and the population composition of lymphocytes, as well as the detection of specific antibodies in the blood serum of guinea pigs immunized with lectin, were indicative of the fact that the preparation was sufficiently immunogenic and induced the activation of the processes of proliferation and activation of lymphocytes during immunogenesis. The lectin isolated from Y. pestis EV outer membrane may be regarded as an additional factor ensuring the contact of the pathogen with the cells of the body and as a promising component of combined plague vaccine.