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Wyniki wyszukiwania dla: MOLECULAR DYNAMICS SIMULATIONS
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Structure determination of UL49.5 transmembrane protein from bovine herpesvirus 1 by NMR spectroscopy and molecular dynamics
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Multiple β-sheet molecular dynamics of amyloid formation from two ABl-SH3 domain peptides
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Long range molecular dynamics study of regulation of eukaryotic glucosamine-6-phosphate synthase activity by UDP-GlcNAc
PublikacjaGlucosamine-6-phosphate (GlcN-6-P) synthase catalyses the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5' diphospho N-acetyl-D-glucosamine (UDPGlcNAc), is an essential substrate for assembly of bacterialand fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which makes it a potential target...
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On the Possibility of the Amphotericin B-Sterol Complex Formation in Cholesterol- and Ergosterol-Containing Lipid Bilayers: A Molecular Dynamics Study
PublikacjaAmphotericin B (AmB) is a well-known membrane-active antibiotic that has been used to treat systemicfungal infections for more than 45 years. Therapeutic application of AmB is based on the fact that it is moreactive against ergosterol-containing membranes of fungal cells than against mammalian membranes withcholesterol. In this paper, we examine the hypothesis according to which the selectivity of the AmB's membraneaction originates...
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The Role of Molecular Structure in Monte Carlo Simulations of the Secondary Electron Yield and Backscattering Coefficient from Methacrylic Acid
PublikacjaIn this paper, we show the influence of the chemical structure of four different conformers on the secondary electron emission and backscattering of an electron beam from a gel of methacrylic acid. The conformers have different permanent dipole moments, which determines the cross sections for elastic collisions with electrons. The cross sections are used in Monte Carlo simulations of an electron beam, which enters the gel of methacrylic...
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Molecular Simulations Using Boltzmann’s Thermally Activated Diffusion - Implementation on ARUZ – Massively-parallel FPGA-based Machine
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Density functional theory-based simulations of sum frequency generation spectra involving methyl stretching vibrations: effect of the molecular model on the deduced molecular orientation and comparison with an analytical approach
PublikacjaThe knowledge of the first hyperpolarizability tensor elements of molecular groups is crucial for a quantitative interpretation of the sum frequency generation (SFG) activity of thin organic films at interfaces. Here, the SFG response of the terminal methyl group of a dodecanethiol (DDT) monolayer has been interpreted on the basis of calculations performed at the density functional theory (DFT) level of approximation. In particular,...
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Comparative molecular dynamics study of dimeric and monomeric forms of HIV-1 protease in ligand bound and unbound state
PublikacjaHuman immunodeficiency virus type 1 protease (HIV-1 PR) is a viral-encoded enzyme that forms a homodimer. HIV-1 PR is essential for replication and assembly of the virus and inactivation of HIV-1 PR enzyme causes production of immature, noninfectious viral particles and thus HIV-1 PR is an attractive target in anti-AIDS drug design. In our current work, we performed molecular dynamics (MD) calculations (500 ns) for two different...
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Application of Multiplexed Replica Exchange Molecular Dynamics to the UNRES Force Field: Tests with α and α+β Proteins
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Self-assembly and interactions of short antimicrobial cationic lipopeptides with membrane lipids: ITC, FTIR and molecular dynamics studies
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Molecular dynamics study of 4-OH-phenylacetyl- D -Y(Me)FQNRPR-NH 2 selectivity to V1a receptor
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Long range molecular dynamics study of interactions of the eukaryotic glucosamine-6-phosphate synthase with fructose-6-phosphate and UDP-GlcNAc
PublikacjaGlucosamine-6-phosphate synthase (EC 2.6.1.16) is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5 diphospho Nacetyl- d-glucosamine (UDP-GlcNAc), is an essential substrate for assembly of bacterial and fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which...
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Effect of heat treatment on the diffusion intermixing and structure of the Cu thin film on Si (111) substrate: a molecular dynamics simulation study
PublikacjaThis work is devoted to the study of the diffusion process at the interface between copper films with a thickness of 2, 3, 4, 7 and 10 atomic monolayers and silicon substrate by molecular dynamics simulation method. For this purpose, the variation of the concentration of copper and silicon along the perpendicular direction to the interface was investigated. An analysis of the density profile along this direction made it possible...
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Arginine-, d-arginine-vasopressin, and their inverso analogues in micellar and liposomic models of cell membrane: CD, NMR, and molecular dynamics studies
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Structural elucidation of transmembrane transporter protein bilitranslocase: Conformational analysis of the second transmembrane region TM2 by molecular dynamics and NMR spectroscopy
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Characteristics of hydration water around hen egg lysozyme as the protein model in aqueous solution. FTIR spectroscopy and molecular dynamics simulation
PublikacjaW niniejszej pracy przedstawiono wyniki badań dotyczące hydratacji białka modelowego - lizozymu z jaja kurzego w roztworze wodnym. Wiodącą techniką stosowaną w badaniach była spektroskopia oscylacyjna FTIR z zastosowaniem techniki rozcieńczenia izotopowego wody półciężkiej HDO w roztworze wody zwykłej. Analiza widma HDO przy pomocy "metody widm zaburzonych" pozwoliła na wyizolowanie widma wody zaburzonej przez lizozym, a tym samym...
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Mechanism of Binding of Antifungal Antibiotic Amphotericin B to Lipid Membranes: An Insight from Combined Single-Membrane Imaging, Microspectroscopy, and Molecular Dynamics
PublikacjaAmphotericin B is a lifesaving polyene antibiotic used in the treatment of systemic mycoses. Unfortunately, the pharmacological applicability of this drug is limited because of its severe toxic side effects. At the same time, the lack of a well-defined mechanism of selectivity hampers the efforts to rationally design safer derivatives. As the drug primarily targets the biomembranes of both fungi and humans, new insights into the...
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Spectroscopic studies on physicochemical properties of selected unsymmetrical bisacridine derivatives and NMR analysis of their interactions with the model sequence Pu22 aided by molecular dynamics
PublikacjaIn recent years, new promising acridine derivatives have appeared, belonging to the unsymmetrical bisacridines (UAs) family with high anticancer activity. Both their physicochemical properties and their mechanism of action at the molecular level have not been thoroughly analyzed so far. Four derivatives were selected for the study, termed as: C-2028, C-2041, C-2045 and C-2053. The first aim of this work was to determine the protonation...
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The Product of Matrix Metalloproteinase Cleavage of Doxorubicin Conjugate for Anticancer Drug Delivery: Calorimetric, Spectroscopic, and Molecular Dynamics Studies on Peptide–Doxorubicin Binding to DNA
PublikacjaMatrix metalloproteinases (MMPs) are extracellular matrix degradation factors, promoting cancer progression. Hence, they could provide an enzyme-assisted delivery of doxorubicin (DOX) in cancer treatment. In the current study, the intercalation process of DOX and tetrapeptide-DOX, the product of the MMPs' cleavage of carrier-linked DOX, into dsDNA was investigated using stationary and time-resolved fluorescence spectroscopy, UV-Vis...
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Analysis of interactions responsible for vasopressin binding to human neurohypophyseal hormone receptors—molecular dynamics study of the activated receptor–vasopressin–Gα systems
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"Car-Parrinello molecular dynamics" jako kluczowe narzędzie informatyczne w badaniach syntezy cienkich warstw diamentowych metodą PA CVD
PublikacjaPraca omawia zastosowanie metody Car-Parrinello MD w symulacji procesu wzrostu cienkich warstw diamentowych w metodzie PAC VD.
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An insight into the mixed quantum mechanical-molecular dynamics simulation of a ZnII-Curcumin complex with a chosen DNA sequence that supports experimental DNA binding investigations
PublikacjaAn important aspect of research pertaining to Curcumin (HCur) is the need to arrest its degradation in aqueous solution and in biological milieu. This may be achieved through complex formation with metal ions. For this reason, a complex of HCur was prepared with ZnII, that is not likely to be active in redox pathways, minimizing further complications. The complex is monomeric, tetrahedral, with one HCur, an acetate and a molecule...
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Preferential solvation in (amide+alcohol) binary mixtures. Part 2. The N-methylpyrrolidinone+methanol mixture at T = 313.15 K: thermodynamic resultsand molecular dynamics calculations.
PublikacjaBadano zjawisko preferencyjnej solwatacji amidu (N-metylopyrrolidonu) przez metanol wykorzystując dwie uzupełniające się metody: bezpośrednich pomiarów własności termodynamicznych roztworu oraz symulacji komputerowych. W metodzie pierwszej dokonano pomiarów wielkości termodynamicznych takich jak: nadmiarowa energia swobodna mieszania, nadmiarowa objętość mieszania oraz współczynnika ściśliwości izotermicznej mieszaniny,...
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Preferential solvation in (amide+alcohol) binary mixtures. Part 1. The N- methylpyrrolidinone+ethanol mixture at T = 313.15 K: thermodynamic resultsand molecular dynamics calculations.
PublikacjaBadano zjawisko preferencyjnej solwatacji amidu (N-metylopyrrolidonu) przez etanol wykorzystując dwie uzupełniające się metody: bezpośrednich pomiarów własności termodynamicznych roztworu oraz symulacji komputerowych. W metodzie pierwszej dokonano pomiarów wielkości termodynamicznych takich jak: nadmiarowa energia swobodna mieszania, nadmiarowa objętość mieszania oraz współczynnika ściśliwości izotermicznej mieszaniny,...
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Investigation of mechanism of desmopressin binding in vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors: Molecular dynamics simulation of the agonist-bound state in the membrane–aqueous system
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Study of New Oxytocin Antagonist Barusiban (Fe200 440) Affinity Toward Human Oxytocin Receptor Versus Vasopressin V1a and V2 Receptors - Molecular Dynamics Simulation in POPC Bilayer
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Toward Mechanosynthesis of Diamondoid Structures: VI. Quantum-Chemical Molecular Dynamics Comparison of Conditions for the STM Tip Driven Mechanosynthesis on Hydrogenated Si(111), Si(110) and Si(100) Surfaces.
Publikacjamożliwość prototypowania przejściowych generacji nano-urządzeń otrzymanych drogą pozycjonowanej mechanosyntezy za pomocą stm wyposażonego w ostrze typu swcnt są analizowane metodą kwantowo-chemicznej dynamiki molekularnej. proponowana strategia syntezy polega na insercji atomów si oraz cząsteczek sih2 we wiązania si-h na uwodornionej powierzchni si(111), si(110) oraz si(100) kryształu krzemu. rezultaty modelowania sugerują, że...
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Keep It Flexible: Driving Macromolecular Rotary Motions in Atomistic Simulations with GROMACS
PublikacjaWe describe a versatile method to enforce the rotation of subsets of atoms, e.g., a protein subunit, in molecular dynamics (MD) simulations. In particular, we introduce a “flexible axis” technique that allows realistic flexible adaptions of both the rotary subunit as well as the local rotation axis during the simulation. A variety of useful rotation potentials were implemented for the GROMACS 4.5 MD package. Application to the...
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Brownian Motion in Optical Tweezers, a Comparison between MD Simulations and Experimental Data in the Ballistic Regime
PublikacjaThe four most popular water models in molecular dynamics were studied in large-scale simulations of Brownian motion of colloidal particles in optical tweezers and then compared with experimental measurements in the same time scale. We present the most direct comparison of colloidal polystyrene particle diffusion in molecular dynamics simulations and experimental data on the same time scales in the ballistic regime. The four most...
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Studies of the Interaction Dynamics in Albumin-Chondroitin Sulfate Systems by Recurrence Method
PublikacjaThe physicochemical basis of lubrication of articular cartilage is still not fully understood. However, the synergy between components of the synovial fluid can be a crucial factor that could explain this phenomenon. This work presents a nonlinear data analysis technique named the recurrence method, applied to the system involving two components of synovial fluid: albumin and chondroitin sulfate (CS) immersed in a water environment....
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The significance of the properties of water for the working cycle of the kinesin molecular motor
PublikacjaExplicit solvent molecular dynamics simulations were performed in this study to investigate and discuss several aspects of the influence of the properties of water on the working cycle of a molecular motor from the kinesin superfamily. The main objects of attention were: the binding of the neck linker and the association of the kinesin and the tubulin. The docking of the neck linker is considered a crucial event during the working...
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Intramolecular transformation of an antifungal antibiotic nystatin A1 into its isomer, iso-nystatin A1 - structural and molecular modeling studies
PublikacjaNystatin A1, a polyene macrolide antifungal antibiotic, in a slightly basic or acidic solution undergoes an intramolecular transformation, yielding a structural isomer, the translactonization product, iso-nystatin A1 with lactone ring diminished by two carbon atoms. Structural evidence is provided by advanced NMR and Mass Spectrometry (MS) studies. Molecular dynamics simulations and quantum mechanics calculations gave the insight...
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Long‐time scale simulations of virus‐like particles from three human‐norovirus strains
PublikacjaThe dynamics of the virus like particles (VLPs) corresponding to the GII.4 Houston, GII.2 SMV, and GI.1 Norwalk strains of human noroviruses (HuNoV) that cause gastroenteritis was investigated by means of long-time (about 30 μs in the laboratory timescale) molecular dynamics simulations with the coarse-grained UNRES force field. The main motion of VLP units turned out to be the bending at the junction between the P1 subdomain (that...
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UNRES-GPU for Physics-Based Coarse-Grained Simulations of Protein Systems at Biological Time- and Size-Scales
PublikacjaThe dynamics of the virus like particles (VLPs) corresponding to the GII.4 Houston, GII.2 SMV, and GI.1 Norwalk strains of human noroviruses (HuNoV) that cause gastroenteritis was investigated by means of long-time (about 30 μs in the laboratory timescale) molecular dynamics simulations with the coarse-grained UNRES force field. The main motion of VLP units turned out to be the bending at the junction between the P1 subdomain (that...
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The Effect of Sterols on Amphotericin B Self-Aggregation in a Lipid Bilayer as Revealed by Free Energy Simulations
PublikacjaAmphotericin B (AmB) is an effective but toxic antifungal drug, known to increase the permeability of the cell membrane, presumably by assembling into transmembrane pores in a sterol-dependent manner. The aggregation of AmB molecules in a phospholipid bilayer is, thus, crucial for the drug’s activity. To provide an insight into the molecular nature of this process, here, we report an atomistic molecular dynamics simulation study...
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Molecular basis and potential activity of HIV-1 reverse transcriptase toward trimethylamine-based compounds
PublikacjaReverse transcriptase (RT) inhibitors are currently used to treat human immunodeficiency virus (HIV)-1 infections. In this work, novel triethylamine derivatives were designed and studied by rigid and flexible docking and molecular dynamics (MD) approaches. An apo form of HIV-1 RT was also studied by MD simulation to analyze comparative response of protein in ligand-bound and ligand-unbound forms. Among newly designed HIV-1 RT inhibitors,...
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Mapping the Structural and Dynamic Determinants of pH-Sensitive Heparin Binding to Granulocyte Macrophage Colony Stimulating Factor
PublikacjaGranulocyte macrophage colony stimulating factor (GMCSF) is an immunomodulatory cytokine that is harnessed as a therapeutic. GMCSF is known to interact with other clinically important molecules, such as heparin, suggesting that endogenous and administered GMCSF has the potential to modulate orthogonal treatment outcomes. Thus, molecular level characterization of GMCSF and its interactions with biologically active compounds is critical...
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Effect of osmolytes on the thermal stability of proteins: replica exchange simulations of Trp-cage in urea and betaine solutions
PublikacjaAlthough osmolytes are known to modulate the folding equilibrium, the molecular mechanism of their effect on thermal denaturation of proteins is still poorly understood. Here, we simulated the thermal denaturation of a small model protein (Trp-cage) in the presence of denaturing (urea) and stabilizing (betaine) osmolytes, using the all-atom replica exchange molecular dynamics simulations. We found that urea destabilizes Trp-cage...
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Short-range order structure and free volume distribution in liquid bismuth: X-ray diffraction and computer simulations studies
PublikacjaThe structure of liquid bismuth was studied by X-ray diffraction and computer simulation methods. The contraction of the atomic structure within the first coordination sphere in the temperature interval of 575- 1225 K is reported. The temperature dependencies of the coordination numbers and of the free volume are analysed. On the basis of the temperature dependencies of the free volume, the temperature dependencies of viscosity...
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Understanding the formation of metastable furan dication in collisions with ions
PublikacjaThis work relies on complementary theoretical and experimental studies of the processes induced by ion-furan collisions. Results of the Molecular Dynamics simulations and exploration of the energy profiles combined with coincidence mass spectrometry provide complete picture of the fragmentation of furan dication.
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Optimization of parallel implementation of UNRES package for coarse‐grained simulations to treat large proteins
PublikacjaWe report major algorithmic improvements of the UNRES package for physics-based coarse-grained simulations of proteins. These include (i) introduction of interaction lists to optimize computations, (ii) transforming the inertia matrix to a pentadiagonal form to reduce computing and memory requirements, (iii) removing explicit angles and dihedral angles from energy expressions and recoding the most time-consuming energy/force terms...
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Molecular hydrogen solvated in water – A computational study
PublikacjaThe aqueous hydrogen molecule is studied with molecular dynamics simulations at ambient temperature and pressure conditions, using a newly developed flexible and polarizable H2 molecule model. The design and implementation of this model, compatible with an existing flexible and polarizable force field for water, is presented in detail. The structure of the hydration layer suggests that first-shell water molecules accommodate the...
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Specific Binding of Cholesterol to the Amyloid Precursor Protein: Structure of the Complex and Driving Forces Characterized in Molecular Detail
PublikacjaC99 is the C-terminal membrane-bound fragment of the amyloid precursor protein that is cleaved by γ-secretase to release Aβ peptides, the hallmark of Alzheimer’s disease (AD). Specific interactions of C99 with cholesterol have been proposed to underlie the recognized role of cholesterol in promoting amyloidogenesis. By using molecular dynamics simulations, we studied cholesterol binding to C99 in a lipid bilayer. We determined...
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Molecular level interpretation of excess infrared spectroscopy
PublikacjaInfrared (IR) spectroscopy is an invaluable tool in studying intermolecular interactions in solvent mixtures. The deviation of the IR spectrum of a mixture from the spectra of its pure components is a sensitive measure of the non-ideality of solutions and the modulation of intermolecular interactions introduced by mutual influence of the components. Excess IR spectroscopy, based on the established notion of excess thermodynamic...
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublikacjaHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Principles of target DNA cleavage and the role of Mg2+ in the catalysis of CRISPR–Cas9
PublikacjaAt the core of the CRISPR–Cas9 genome-editing technology, the endonuclease Cas9 introduces site-specific breaks in DNA. However, precise mechanistic information to ameliorate Cas9 function is still missing. Here, multimicrosecond molecular dynamics, free energy and multiscale simulations are combined with solution NMR and DNA cleavage experiments to resolve the catalytic mechanism of target DNA cleavage. We show that the conformation...
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Molecular basis and quantitative assessment of TRF1 and TRF2 protein interactions with TIN2 and Apollo peptides
PublikacjaShelterin is a six-protein complex (TRF1, TRF2, POT1, RAP1, TIN2, and TPP1) that also functions in smaller subsets in regulation and protection of human telomeres. Two closely related proteins, TRF1 and TRF2, make high-affinity contact directly with double-stranded telomeric DNA and serve as a molecular platform. Protein TIN2 binds to TRF1 and TRF2 dimer-forming domains, whereas Apollo makes interaction only with TRF2. To elucidate...
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Computational methods for calculation of binding free energy for ligand-receptor complexes
PublikacjaAccurate description of the molecular complexes energetic influence is required for understanding of many biological functions carried out by proteins. Therefore, estimation of binding free energy for ligand-receptor complexes is of highest importance for structure-based ligand design and drug discovery approaches.Experimental methods of determination of difference in Gibbs'es free energy have many limitations. Thus, computational...
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Thermodynamics and kinetics of amphotericin B self-association in aqueous solution characterized in molecular detail
PublikacjaAmphotericin B (AmB) is a potent but toxic drug commonly used to treat systemic mycoses. Its efficiency as a therapeutic agent depends on its ability to discriminate between mammalian and fungal cell membranes. The association of AmB monomers in an aqueous environment plays an important role in drug selectivity, as oligomers formed prior to membrane insertion – presumably dimers – are believed to act differently on fungal (ergosterol-rich)...
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Visualizing spatially decomposed intermolecular correlations in the infrared spectra of aprotic liquids
PublikacjaInfrared (IR) spectroscopy is commonly used to study intermolecular interactions in the liquid phase, including solvation phenomena. On the other hand, ab initio molecular dynamics (AIMD) simulations offer the possibility to obtain IR spectra from first principles. Surpassing the experiment, AIMD simulations can deliver additional information on the spatial intermolecular correlations underlying the IR spectrum of the liquid. Although...