Publications by authors named "Nikita Polyakov"

The process of stone formation in the human body remains incompletely understood, which requires clinical and laboratory studies and the formulation of a new endogenous, nanotechnological concept of the mechanism of origin and formation of crystallization centers. Previously, the mechanism of sialolithiasis was considered a congenital disease associated with the pathology of the ducts in the structure of the glands themselves. To date, such morphological changes of congenital nature can be considered from the position of the intrauterine formation of endogenous bacterial infections complicated by the migration of antigenic structures initiating the formation of crystallization centers.

View Article and Find Full Text PDF

Background: Protease S (PrtS) from Photorhabdus laumondii belongs to the group of protealysin-like proteases (PLPs), which are understudied factors thought to play a role in the interaction of bacteria with other organisms. Since P. laumondii is an insect pathogen and a nematode symbiont, the analysis of the biological functions of PLPs using the PrtS model provides novel data on diverse types of interactions between bacteria and hosts.

View Article and Find Full Text PDF

Endopeptidases IdeS and IdeZ (streptococcal virulence factors that specifically cleave IgG heavy chains) are of particular interest because of their potential use in biotechnology, medicine, and veterinary. Genes encoding these enzymes were cloned and expressed in Escherichia coli heterologous expression system (ideS was cloned from a Streptococcus pyogenes collection strain; ideZ from Streptococcus zooepidemicus was synthesized). The 6His-tag was introduced into the amino acid sequence of each endopeptidase, and IdeS and IdeZ were purified by metal affinity chromatography to an apparent homogeneity (according to polyacrylamide gel electrophoresis).

View Article and Find Full Text PDF

Extracellular matrix plays a pivotal role in biofilm biology and proposed as a potential target for therapeutics development. As matrix is responsible for some extracellular functions and influence bacterial cytotoxicity against eukaryotic cells, it must have unique protein composition. P.

View Article and Find Full Text PDF

A new platform for creating anti-coronavirus epitope vaccines has been developed. Two loop-like epitopes with lengths of 22 and 42 amino acid residues were selected from the receptor-binding motif of the Spike protein from the SARS-CoV-2 virus that participate in a large number of protein-protein interactions in the complexes with ACE2 and neutralizing antibodies. Two types of hybrid proteins, including one of the two selected epitopes, were constructed.

View Article and Find Full Text PDF

species are common in tropical and subtropical zones in environmental samples according to numerous studies. Here, we describe an environmental case of resident in biofilms associated with spp. roots in Moscow region, Russia (warm-summer humid continental climate zone).

View Article and Find Full Text PDF

Antibacterial lysins are promising proteins that are active against both antibiotic-susceptible and antibiotic-resistant bacterial strains. However, a major limitation of antibacterial lysins is their fast elimination from systemic circulation. PEGylation increases the plasma half-life of lysins but renders them inactive.

View Article and Find Full Text PDF

The increasing prevalence of antibiotic-resistant strains of pathogenic bacteria is a major healthcare problem. Antibacterial lysins are enzymes that cleave the peptidoglycan of the bacterial cell wall. These proteins hold potential as a supplement or an alternative to traditional antibiotics since they are active against antibiotic resistant strains.

View Article and Find Full Text PDF

Background: is a Gram-positive bacterium that causes severe illnesses in the human population. The capacity of strains to form biofilms on biotic and abiotic surfaces creates serious problems for treatment of hospital infections and has stimulated efforts to develop new means of specific protection or immunotherapy.

Material And Methods: We found that rabbit serum raised against crude concentrated liquid culture significantly decreased the development of staphylococcal biofilm .

View Article and Find Full Text PDF

Induction of a robust and long-lived mucosal immune response during vaccination is critical to achieve protection against numerous pathogens. However, traditional injected vaccines are generally poor inducers of mucosal immunity. One of the effective strategies to improve vaccine efficacy is incorporation of adjuvant molecules that enhance and polarize adaptive immune reactions.

View Article and Find Full Text PDF

Sterile (noninfected) inflammation underlies the pathogenesis of many widespread diseases, such as allergies and autoimmune diseases. The evolutionarily conserved innate immune system is considered to play a key role in tissue injury recognition and the subsequent development of sterile inflammation; however, the underlying molecular mechanisms are not yet completely understood. Here, we show that cholesterol sulfate, a molecule present in relatively high concentrations in the epithelial layer of barrier tissues, is selectively recognized by Mincle (Clec4e), a C-type lectin receptor of the innate immune system that is strongly up-regulated in response to skin damage.

View Article and Find Full Text PDF

A new Bacillus licheniformis strain, 603, isolated from a mixture of drilling fluid and subsurface thermal water, has been found to produce a cyclic lipopeptide which is released into cultural medium as well as present in cells as the major lipid constituent (57% of the total cell lipids extractable with 2:1 chloroform-methanol). The quantitative ratio of the extracellular and intracellular lipopeptide has been estimated as 23:10. The metabolite represents a heptapeptide, L-Asp-->L-Leu-->L-Leu-->L-Val-->L-Val-->L-Glu-->L-Leu, N-acylated to the N-terminal amino acid, L-Asp, by a 3-hydroxy fatty acid (from 13:0 to 17:0 with n-, iso-, and anteiso-chains), the 3-OH group of which is esterified by the C-terminal amino acid, L-Leu.

View Article and Find Full Text PDF