Molecular dynamics of three different α-helices in ribosomal protein L25 from .

A true native protein state is realized in a water solution where proteins exhibit their dynamic properties important for the functioning. This is way we have analyzed the dynamics of α-helices inside ribosomal protein L25 from in a water solution. The dynamics of only main chain Cα-atoms have been simulated along the five independent trajectories at a total time 200ns.

Molecular Dynamics Simulation of Self-Assembly Processes of Diphenylalanine Peptide Nanotubes and Determination of Their Chirality.

In this work, we further developed a new approach for modeling the processes of the self-assembly of complex molecular nanostructures using molecular dynamics methods; in particular, using a molecular dynamics manipulator. Previously, this approach was considered using the example of the self-assembly of a phenylalanine helical nanotube. Now, a new application of the algorithm has been developed for implementing a similar molecular dynamic self-assembly into helical structures of peptide nanotubes (PNTs) based on other peptide molecules-namely diphenylalanine (FF) molecules of different chirality L-FF and D-FF.

Comparison of deep learning models with simple method to assess the problem of antimicrobial peptides prediction.

Antibiotic-resistant strains are an emerging threat to public health. The usage of antimicrobial peptides (AMPs) is one of the promising approaches to solve this problem. For the development of new AMPs, it is necessary to have reliable prediction methods.

Measurement of selection coefficients from genomic samples of adapting populations by computer modeling.

The existing protocols of measuring the selection coefficients of loci neglect linkage effects existing between loci. This protocol is free from this limitation. The protocol inputs a set of DNA sequences at three time points, removes conserved sites, and estimates selection coefficients.

Molecular dynamics of α-helical structure: poly-l-glutamic acid.

Communicated by Ramaswamy H. Sarma.

Molecular Dynamics Simulation of the Thermal Behavior of Hydroxyapatite.

Hydroxyapatite (HAP) is the main mineral component of bones and teeth. Due to its biocompatibility, HAP is widely used in medicine as a filler that replaces parts of lost bone and as an implant coating that promotes new bone growth. The modeling and calculations of the structure and properties of HAP showed that various structural defects have a significant effect on the properties of the material.

The Increased Amyloidogenicity of Spike RBD and pH-Dependent Binding to ACE2 May Contribute to the Transmissibility and Pathogenic Properties of SARS-CoV-2 Omicron as Suggested by In Silico Study.

SARS-CoV-2 is a rapidly evolving pathogen that has caused a global pandemic characterized by several consecutive waves. Based on epidemiological and NGS data, many different variants of SARS-CoV-2 were described and characterized since the original variant emerged in Wuhan in 2019. Notably, SARS-CoV-2 variants differ in transmissibility and pathogenicity in the human population, although the molecular basis for this difference is still debatable.

SARS-CoV-2 herd immunity of the Kyrgyz population in 2021.

In the fight against coronavirus infection, control of the immune response is of decisive importance, an important component of which is the seroprevalence of antibodies to SARS-CoV-2. Immunity to SARS-CoV-2 is formed either naturally or artificially through vaccination. The purpose of this study was to assess the seroprevalence of antibodies to SARS-CoV-2 in the population of Kyrgyzstan.

Is It Possible to Find an Antimicrobial Peptide That Passes the Membrane Bilayer with Minimal Force Resistance? An Attempt at a Predictive Approach by Molecular Dynamics Simulation.

There is still no answer to the mechanism of penetration of AMP peptides through the membrane bilayer. Several mechanisms for such a process have been proposed. It is necessary to understand whether it is possible, using the molecular dynamics method, to determine the ability of peptides of different compositions and lengths to pass through a membrane bilayer.

Molecular Dynamics Simulation Study of the Self-Assembly of Phenylalanine Peptide Nanotubes.

In this paper, we propose and use a new approach for a relatively simple technique for conducting MD simulation (MDS) of various molecular nanostructures, determining the trajectory of the MD run and forming the final structure using external force actions. A molecular dynamics manipulator (MD manipulator) is a controlled MDS type. As an example, the applicability of the developed algorithm for assembling peptide nanotubes (PNT) from linear phenylalanine (F or Phe) chains of different chirality is presented.

Quantitative Assessment of Chirality of Protein Secondary Structures and Phenylalanine Peptide Nanotubes.

In this study we consider the features of spatial-structure formation in proteins and their application in bioengineering. Methods for the quantitative assessment of the chirality of regular helical and irregular structures of proteins are presented. The features of self-assembly of phenylalanine (F) into peptide nanotubes (PNT), which form helices of different chirality, are also analyzed.

Is there an advantageous arrangement of aromatic residues in proteins? Statistical analysis of aromatic interactions in globular proteins.

The aim of this study was to evaluate the favorability of different conformations of aromatic residues in proteins by analysing the occurrence of particular conformations. The clustering of protein structures from the Protein Data Bank (PDB) was performed. Conformations of interacting aromatic residues were analyzed for 511 282 pairs in 35 493 protein structures sharing less than 50% identity.

Signal transfer in human protein tyrosine phosphatase PTP1B from allosteric inhibitor P00058.

Protein tyrosine phosphatases constitute a family of cytosolic and receptor-like signal transducing enzymes that catalyze the hydrolysis of phospho-tyrosine residues of phosphorylated proteins. PTP1B, encoded by , is a key negative regulator of insulin and leptin receptor signaling, linking it to two widespread diseases: type 2 diabetes mellitus and obesity. Here, we present crystal structures of the PTP1B apo-enzyme and a complex with a newly identified allosteric inhibitor, 2-(2,5-dimethyl-pyrrol-1-yl)-5-hydroxy-benzoic acid, designated as P00058.

Approbation of russian test strips for antimicrobial susceptibility testing of microorganisms by gradient diffusion method (E-test).

The most reliable criterion for the microorganisms antibiotic susceptibility is the value of the minimum inhibitory concentration (MIC). The gradient diffusion method (epsilometric test, e-test), carried out using test strips impregnated with an antimicrobial agent, allows to obtain the quantitative value of MIC, bypassing the time-consuming steps of the traditional method of serial dilutions. We tested strips for the epsilometric test, developed at Saint-Petersburg Pasteur Institute.

Disordered Residues and Patterns in the Protein Data Bank.

We created a new library of disordered patterns and disordered residues in the Protein Data Bank (PDB). To obtain such datasets, we clustered the PDB and obtained the groups of chains with different identities and marked disordered residues. We elaborated a new procedure for finding disordered patterns and created a new version of the library.

[Antimicrobial resistance and clinical significant resistance mechanisms of Salmonella isolated in 2014-2018 in St.Petersburg, Russia.].

The article presents the results of antimicrobial resistance monitoring of Salmonella isolated from children and adults with diarrhea in St. Petersburg in 2014-2018. In 746 isolates of 42 serovars more than 90,0% belonged to three: S.

Comparative mechanical unfolding studies of spectrin domains R15, R16 and R17.

Spectrins belong to repetitive three-helix bundle proteins that have vital functions in multicellular organisms and are of potential value in nanotechnology. To reveal the unique physical features of repeat proteins we have studied the structural and mechanical properties of three repeats of chicken brain α-spectrin (R15, R16 and R17) at the atomic level under stretching at constant velocities (0.01, 0.

Available Instruments for Analyzing Molecular Dynamics Trajectories.

Molecular dynamics trajectories are the result of molecular dynamics simulations. Trajectories are sequential snapshots of simulated molecular system which represents atomic coordinates at specific time periods. Based on the definition, in a text format trajectory files are characterized by their simplicity and uselessness.

Atomic-Scale Engineering of Abrupt Interface for Direct Spin Contact of Ferromagnetic Semiconductor with Silicon.

Control and manipulation of the spin of conduction electrons in industrial semiconductors such as silicon are suggested as an operating principle for a new generation of spintronic devices. Coherent injection of spin-polarized carriers into Si is a key to this novel technology. It is contingent on our ability to engineer flawless interfaces of Si with a spin injector to prevent spin-flip scattering.

Structural coupling across the direct EuO/Si interface.

The ferromagnetic semiconductor EuO is believed to be an effective spin injector when directly integrated with silicon (Si). Injection through spin-selective ohmic contact requires superb structural quality of the interface EuO/Si. A recent breakthrough in manufacturing free-of-buffer-layer EuO/Si junctions calls for structural studies of the interface between the semiconductors.

Direct epitaxial integration of the ferromagnetic semiconductor EuO with silicon for spintronic applications.

Following a remarkable success of metallic spintronics, tremendous efforts have been invested into the less developed semiconductor spintronics, in particular, with the aim to produce three-terminal spintronic devices, e.g., spin transistors.

Mechanical stability analysis of the protein L immunoglobulin-binding domain by full alanine screening using molecular dynamics simulations.

This article is the first to study the mechanical properties of the immunoglobulin-binding domain of protein L (referred to as protein L) and its mutants at the atomic level. In the structure of protein L, each amino acid residue (except for alanines and glycines) was replaced sequentially by alanine. Thus, 49 mutants of protein L were obtained.

Right- and left-handed three-helix proteins. II. Similarity and differences in mechanical unfolding of proteins.

Here, we study mechanical properties of eight 3-helix proteins (four right-handed and four left-handed ones), which are similar in size under stretching at a constant speed and at a constant force on the atomic level using molecular dynamics simulations. The analysis of 256 trajectories from molecular dynamics simulations with explicit water showed that the right-handed three-helix domains are more mechanically resistant than the left-handed domains. Such results are observed at different extension velocities studied (192 trajectories obtained at the following conditions: v = 0.

[Mesothelium and malignant mesothelioma of the pericardium].

Malignant mesothelioma of the pericardium is characterized by atypical solid growth of mesothelium with formation of atypical cavities, slits surrounded by a fibrous stroma. Unless early biopsy, diagnosis and surgery, the prognosis is unfavourable. It is desirable to create immunomorphological test for mesothelium.