Publications by authors named "Manuvera V"

Introduction: WhiA is a conserved protein found in numerous bacteria. It consists of an HTH DNA-binding domain linked with a homing endonuclease (HEN) domain. WhiA is one of the most conserved transcription factors in reduced bacteria of the class Mollicutes.

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Study of mechanisms by which antibodies recognize different viral strains is necessary for the development of new drugs and vaccines to treat COVID-19 and other infections. Here, we report 2.5 Å cryo-EM structure of the SARS-CoV-2 Delta trimeric S-protein in complex with Fab of the recombinant analog of REGN10987 neutralizing antibody.

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Human cell lines play an important role in biotechnology and pharmacology. For them to grow, they need complex nutrient media containing signaling proteins - growth factors. We have tested a new approach that reduces the need of cultured human cell lines for exogenous growth factors.

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Introduction: The recently developed platelet aggregation technique based on low-angle light scattering (LaSca) in diluted platelet-rich plasma (PRP) requires only a small sample volume and provides information about platelet aggregation and shape change. This study aimed to investigate the influence of preanalytical and analytical variables and to validate the method in a real-life pediatric hematology hospital setting.

Methods: Platelet aggregation was induced by ADP in diluted PRP in the presence of 2 mM calcium at 23 °C.

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  • The study found a new anticoagulant protein from the saliva of medicinal leeches, which showed strong ability to suppress blood coagulation.
  • This protein was tested against commonly used anticoagulants like hirudin and demonstrated superior inhibition in certain assays, though hirudin had better results in direct thrombin inhibition tests.
  • The newly identified protein shares similarities with antistatin, indicating it could potentially inhibit other proteins involved in blood coagulation.
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  • Self-assembling nanoparticles (saNP) and nanofibers were identified from SARS-CoV-2 proteins, showing various sizes and consistent solid structures rather than hollow vesicles.
  • The stability of these saNP was confirmed over two years, maintaining their integrity even under multiple freeze-thaw cycles.
  • Interactions with specific cell receptors indicated efficient entry of S1 and RBD saNP into certain cells, and their amyloid-like characteristics raise concerns about potential impacts on protein health and vaccine stability in patients.
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  • Recombinant proteins from E. coli often have endotoxin contamination, which complicates their use.
  • Two methods were tested to create E. coli strains with lower lipopolysaccharide (LPS) levels: knocking out genes in the LPS biosynthesis pathway and increasing YciM protein expression.
  • Both approaches successfully reduced endotoxin levels in the purified eGFP samples.
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Structure and function of bacterial nucleoid is controlled by the nucleoid-associated proteins (NAP). In any phase of growth, various NAPs, acting sequentially, condense nucleoid and facilitate formation of its transcriptionally active structure. However, in the late stationary phase, only one of the NAPs, Dps protein, is strongly expressed, and DNA-protein crystals are formed that transform nucleoid into a static, transcriptionally inactive structure, effectively protected from the external influences.

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  • Destabilase is an enzyme from the medical leech that can break down bacterial cell walls and dissolve blood clots.
  • It is affected by sodium chloride, which stops its ability to work, but the reason for this wasn't clear until now.
  • Researchers discovered the structure of destabilase and think that a different part of the enzyme helps it break down blood clots instead of what was thought before; this could help design new medicines.
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  • * The study introduces a new bacteriophage called vB_KpnP_Klyazma, which was isolated from river water and shows lytic activity against certain bacterial strains with a specific capsule type.
  • * A key finding is that the phage's receptor-binding protein, a polysaccharide depolymerase, can modify bacterial capsular polysaccharides, opening potential uses in antimicrobial therapy even if it doesn't kill bacteria directly.
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The life cycle of severe acute respiratory syndrome coronavirus 2 includes several steps that are supposedly mediated by liquid-liquid phase separation (LLPS) of the viral nucleocapsid protein (N) and genomic RNA. To facilitate the rational design of LLPS-targeting therapeutics, we modeled N-RNA biomolecular condensates in vitro and analyzed their sensitivity to several small-molecule antivirals. The model condensates were obtained and visualized under physiological conditions using an optimized RNA sequence enriched with N-binding motifs.

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Mutations in surface proteins enable emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to escape a substantial fraction of neutralizing antibodies and may thus weaken vaccine-driven immunity. To compare available vaccines and justify revaccination, rapid evaluation of antibody (Ab) responses to currently circulating SARS-CoV-2 variants of interest (VOI) and concern (VOC) is needed. Here, we developed a multiplex protein microarray-based system for rapid profiling of anti-SARS-CoV-2 Ab levels in human sera.

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COVID-19 caused by SARS-CoV-2 is continuing to spread around the world and drastically affect our daily life. New strains appear, and the severity of the course of the disease itself seems to be decreasing, but even people who have been ill on an outpatient basis suffer post-COVID consequences. Partly, it is associated with the autoimmune reactions, so debates about the development of new vaccines and the need for vaccination/revaccination continue.

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: Nanosilver possesses antiviral, antibacterial, anti-inflammatory, anti-angiogenesis, antiplatelet, and anticancer properties. The development of disinfectants, inactivated vaccines, and combined etiotropic and immunomodulation therapy against respiratory viral infections, including COVID-19, remains urgent. Our goal was to determine the SARS-CoV-2 molecular targets (genomic RNA and the structural virion proteins S and N) for silver-containing nanomaterials.

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The SARS-CoV-2 pandemic is a big challenge for humanity. The COVID-19 severity differs significantly from patient to patient, and it is important to study the factors protecting from severe forms of the disease. Respiratory microbiota may influence the patient's susceptibility to infection and disease severity due to its ability to modulate the immune system response of the host organism.

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Leeches are amazing animals that can be classified as conditionally poisonous animals since the salivary cocktail they produce is injected directly into the victim, and its components have strictly defined biological purposes, such as preventing blood clot formation. Thrombolytic drugs are mainly aimed at treating newly formed blood clots. Aged clots are stabilized by a large number of isopeptide bonds that prevent the action of thrombolytics.

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The structure and dynamics of bacterial nucleoids play important roles in regulating gene expression. Bacteria of class Mollicutes and, in particular, mycoplasmas feature extremely reduced genomes. They lack multiple structural proteins of the nucleoid, as well as regulators of gene expression.

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In the search for anti-SARS-CoV-2 drugs, much attention is given to safe and widely available native compounds. The green tea component epigallocatechin 3 gallate (EGCG) is particularly promising because it reportedly inhibits viral replication and viral entry in vitro. However, conclusive evidence for its predominant activity is needed.

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The global problem of emerging resistance of microorganisms to antibiotics makes the search for new natural substances with antibacterial properties relevant. Such substances include peptidoglycan recognition proteins (PGLYRP), which are the components of the innate immunity of many organisms, including humans. These proteins have a unique mechanism of action that allows them to evade the resistance of bacteria to them, as well as to be active against both Gram-positive and Gram-negative bacteria.

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Infectious bursal disease virus (IBDV), which infects young chickens, is one of the most important pathogens that harm the poultry industry. Evaluation of the immune status of birds before and after vaccination is of great importance for controlling the disease caused by this virus. Therefore, the development of low-cost and easy-to-manufacture test systems for IBDV antibody detection remains an urgent issue.

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Background: Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today.

Results: We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana.

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The rise of antibiotic resistance has necessitated the development of alternative strategies for the treatment of infectious diseases. Antimicrobial peptides (AMPs), components of the innate immune response in various organisms, are promising next-generation drugs against bacterial infections. The ability of the medicinal leech Hirudo medicinalis to store blood for months with little change has attracted interest regarding the identification of novel AMPs in this organism.

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Under severe or prolonged stress, bacteria produce a nonspecific DNA-binding protein (Dps), which effectively protects DNA against damaging agents both in vitro and in vivo by forming intracellular biocrystals. The phenomenon of protective crystallization of DNA in living cells has been intensively investigated during the last two decades; however, the results of studies are somewhat contradictory, and up to now, there has been no direct determination of a Dps-DNA crystal structure. Here, we report the in vitro analysis of the vital process of Dps-DNA co-crystallization using two complementary structural methods: synchrotron small-angle X-ray scattering in solution and cryo-electron tomography.

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A novel strain of infectious bursal disease virus, named DD1, was isolated from broiler chickens in Russia in 2016. Here, we present its complete genome sequence. Nucleotide sequence analysis of both segments of the virus suggests that it belongs to a group of very virulent strains.

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