Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "molecular dynamics" wg kryterium: Temat


Wyświetlanie 1-9 z 9
Tytuł:
Effect of antisense peptide binding on the dimerization of human cystatin C - gel electrophoresis and molecular modeling studies.
Autorzy:
Stachowiak, Krystyna
Rodziewicz-Motowidło, Sylwia
Sosnowska, Renata
Kasprzykowski, Franciszek
Łankiewicz, Leszek
Grubb, Anders
Grzonka, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/1043334.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
dimerization
antisense peptides
human cystatin C
molecular dynamics
Opis:
Human cystatin C (HCC) shows a tendency to dimerize. This process is particularly easy in the case of the L68Q HCC mutant and might lead to formation of amyloid deposits in brain arteries of young adults. Our purpose was to find ligands of monomeric HCC that can prevent its dimerization. Eleven antisense peptide ligands of monomeric HCC were designed and synthesized. The influence of these ligands on HCC dimerization was studied using gel electrophoresis and molecular modeling methods. The results suggest that all the designed peptides interact with monomeric HCC facilitating its dimerization rather than preventing it.
Źródło:
Acta Biochimica Polonica; 2004, 51, 1; 153-160
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the Glu342Lys mutation in α1-antitrypsin on its structure, studied by molecular modelling methods.
Autorzy:
Jezierski, Grzegorz
Pasenkiewicz-Gierula, Marta
Powiązania:
https://bibliotekanauki.pl/articles/1044164.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
serpins
protein structure
energy minimisation
molecular dynamics simulation
Opis:
The structure of native α1-antitrypsin, the most abundant protease inhibitor in human plasma, is characterised primarily by a reactive loop containing the centre of proteinase inhibition, and a β-sheet composed of five strands. Mobility of the reactive loop is confined as a result of electrostatic interactions between side chains of Glu342 and Lys290, both located at the junction of the reactive loop and the β structure. The most common mutation in the protein, resulting in its inactivation, is Glu342→Lys, named the Z mutation. The main goal of this work was to investigate the influence of the Z mutation on the structure of α1-antitrypsin. Commonly used molecular modelling methods have been applied in a comparative study of two protein models: the wild type and the Z mutant. The results indicate that the Z mutation introduces local instabilities in the region of the reactive loop. Moreover, even parts of the protein located far apart from the mutation region are affected. The Z mutation causes a relative change in the total energy of about 3%. Relatively small root mean square differences between the optimised structures of the wild type and the Z mutant, together with detailed analysis of 'conformational searching' process, lead to the hypothesis that the Z mutation principally induces a change in the dynamics of α1-antitrypsin.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 65-75
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free energy of helix propagation in short polyalanine chains determined from peptide growth simulations of La3+-binding model peptides. Comparison with experimental data
Autorzy:
Maciejczyk, Maciej
Hermans, Jan
Bierzyński, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1041277.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
thermodynamics
peptide
helix-coil equilibrium
thermodynamic integration
molecular dynamics
Opis:
Molecular dynamics (MD) is, at present, a unique tool making it possible to study, at the atomic level, conformational transitions in peptides and proteins. Nevertheless, because MD calculations are always based on a more or less approximate physical model, using a set of approximate parameters, their reliability must be tested by comparison with experimental data. Unfortunately, it is very difficult to find a peptide system in which conformational transitions can be studied both experimentally and using MD simulations so that a direct comparison of the results obtained in both ways could be made. Such a system, containing a rigid α-helix nucleus stabilized by La3+ coordination to a 12-residue sequence taken from an EF-hand protein has recently been used to determine experimentally the helix propagation parameters in very short polyalanine segments (Goch et al. (2003) Biochemistry 42: 6840-6847). The same parameters were calculated here for the same peptide system using the peptide growth simulation method with, alternatively, charmm 22 and cedar potential energy functions. The calculated free energies of the helix-coil transition are about two times too large for cedar and even three times too large for charmm 22, as compared with the experimental values. We suggest that these discrepancies have their origin in the incorrect representation of unfolded peptide backbone in solution by the molecular mechanics force fields.
Źródło:
Acta Biochimica Polonica; 2006, 53, 1; 121-130
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular docking-based test for affinities of two ligands toward vasopressin and oxytocin receptors.
Autorzy:
Ślusarz, Rafał
Kaźmierkiewicz, Rajmund
Giełdoń, Artur
Lammek, Bernard
Ciarkowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1044173.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
simulated annealing
bioligand docking
GPCR receptor/bioligand interaction
molecular dynamics
Opis:
Molecular docking simulations are now fast developing area of research. In this work we describe an effective procedure of preparation of the receptor-ligand complexes. The amino-acid residues involved in ligand binding were identified and described.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 131-135
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular dynamics simulation studies of lipid bilayer systems.
Autorzy:
Pasenkiewicz-Gierula, Marta
Murzyn, Krzysztof
Róg, Tomasz
Czaplewski, Cezary
Powiązania:
https://bibliotekanauki.pl/articles/1044295.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
phosphatidylethanolamine
cholesterol
vasopressin receptor,molecular dynamics simulations
magainin-2
phosphatidylcholine
phosphatidylglycerol
Opis:
The main structural element of biological membranes is a liquid-crystalline lipid bilayer. Other constituents, i.e. proteins, sterols and peptides, either intercalate into or loosely attach to the bilayer. We applied a molecular dynamics simulation method to study membrane systems at various levels of compositional complexity. The studies were started from simple lipid bilayers containing a single type phosphatidylcholine (PC) and water molecules (PC bilayers). As a next step, cholesterol (Chol) molecules were introduced to the PC bilayers (PC-Chol bilayers). These studies provided detailed information about the structure and dynamics of the membrane/water interface and the hydrocarbon chain region in bilayers built of various types of PCs and Chol. This enabled studies of membrane systems of higher complexity. They included the investigation of an integral membrane protein in its natural environment of a PC bilayer, and the antibacterial activity of magainin-2. The latter study required the construction of a model bacterial membrane which consisted of two types of phospholipids and counter ions. Whenever published experimental data were available, the results of the simulations were compared with them.
Źródło:
Acta Biochimica Polonica; 2000, 47, 3; 601-611
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical studies of binding modes of two covalent inhibitors of cysteine proteases.
Autorzy:
Drabik, Piotr
Politowska, Ewa
Czaplewski, Cezary
Kasprzykowski, Franciszek
Łankiewicz, Leszek
Ciarkowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1044228.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cysteine proteases
covalent protease inhibitors
constrained simulated annealing
papain
molecular dynamics
Opis:
Physiological and pathological roles of cysteine proteases make them important targets for inhibitor development. Although highly potent inhibitors of this group of enzymes are known, their major drawback is a lack of sufficient specificity. Two cysteine protease covalent inhibitors, viz. (i) Z-RL-deoxo-V-peptide-epoxysuccinyl hybrid, and (ii) Z-RLVG-methyl-, have been developed and modeled in the catalytic pocket of papain, an archetypal thiol protease. A number of configurations have been generated and relaxed for each system using the AMBER force field. The catalytic pockets S3 and S4 appear rather elusive in view of the observed inhibitors' flexibility. This suggest rather limited chances for the development of selective structure-based inhibitors of thiol proteases, designed to exploit differences in the structure of catalytic pockets of various members of this family.
Źródło:
Acta Biochimica Polonica; 2000, 47, 4; 1061-1066
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The intercalation of imidazoacridinones into DNA induces conformational changes in their side chain.
Autorzy:
Mazerski, Jan
Muchewicz, Karolina
Powiązania:
https://bibliotekanauki.pl/articles/1044393.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
molecular dynamics simulations
conformational changes
structure of intercalation complex
C-1311
antitumor drugs
imidazoacridinones
Opis:
Imidazoacridinones (IAs) are a new group of highly active antitumor compounds. The intercalation of the IA molecule into DNA is the preliminary step in the mode of action of these compounds. There are no experimental data about the structure of an intercalation complex formed by imidazoacridinones. Therefore the design of new potentially better compounds of this group should employ the molecular modelling techniques. The results of molecular dynamics simulations performed for four IA analogues are presented. Each of the compounds was studied in two systems: i) in water, and ii) in the intercalation complex with dodecamer duplex d(GCGCGCGCGCGC)2. Significant differences in the conformation of the side chain in the two environments were observed for all studied IAs. These changes were induced by electrostatic as well as van der Waals interactions between the intercalator and DNA. Moreover, the results showed that the geometry of the intercalation complex depends on: i) the chemical constitution of the side chain, and ii) the substituent in position 8 of the ring system.
Źródło:
Acta Biochimica Polonica; 2000, 47, 1; 65-78
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of side chains in the interaction of new antitumor pyrimidoacridinetriones with DNA: Molecular dynamics simulations.
Autorzy:
Mazerski, Jan
Antonini, Ippolito
Martelli, Sante
Powiązania:
https://bibliotekanauki.pl/articles/1044390.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
molecular dynamics simulations
structure of intercalation complex
pyrimidoacridinetrione antitumor agents
role of side chain(s)
Opis:
Pyrimidoacridinetriones (PATs) are a new group of highly active antitumor compounds. It seems reasonable to assume that, like for some other acridine derivatives, intercalation into DNA is a necessary, however not a sufficient condition for antitumor activity of these compounds. Rational design of new compounds of this chemotype requires knowledge about the structure of the intercalation complex, as well as about interactions responsible for its stability. Computer simulation techniques such as molecular dynamics (MD) may provide valuable information about these problems. The results of MD simulations performed for three rationally selected PATs are presented in this paper. The compounds differ in the number and position of side chains. Each of the compounds was simulated in two systems: i) in water, and ii) in the intercalation complex with the dodecamer duplex d(GCGCGCGCGCGC)2. The orientation of the side chain in relation to the ring system is determined by the position of its attachment. Orientation of the ring system inside the intercalation cavity depends on the number and position of side chain(s). The conformations of the side chain(s) of all PATs studied in the intercalation complex were found to be very similar to those observed in water.
Źródło:
Acta Biochimica Polonica; 2000, 47, 1; 47-57
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical models of catalytic domains of protein phosphatases 1 and 2A with Zn2+ and Mn2+ metal dications and putative bioligands in their catalytic centers.
Autorzy:
Woźniak-Celmer, Edyta
Ołdziej, Stanisław
Ciarkowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1044161.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
protein phosphatase inhibitors
constrained simulated annealing
protein phosphatase 1A and 2B
molecular dynamics
homology modeling
Opis:
The oligomeric metalloenzymes protein phosphatases dephosphorylate OH groups of Ser/Thr or Tyr residues of proteins whose actions depend on the phosphorus signal. The catalytic units of Ser/Thr protein phosphatases 1, 2A and 2B (PP1c, PP2Ac and PP2Bc, respectively), which exhibit about 45% sequence similarity, have their active centers practically identical. This feature strongly suggests that the unknown structure of PP2Ac could be successfully homology-modeled from the known structures of PP1c and/or PP2Bc. Initially, a theoretical model of PP1c was built, including a phosphate and a metal dication in its catalytic site. The latter was modeled, together with a structural hydroxyl anion, as a triangular pseudo-molecule (Zno or Mno), composed of two metal cations (double Zn2+ or Mn2+, respectively) and the OH- group. To the free PP1c two inhibitor sequences R29RRRPpTPAMLFR40 of DARPP-32 and R30RRRPpTPATLVLT42 of Inhibitor-1, and two putative substrate sequences LRRApSVA and QRRQRKpRRTI were subsequently docked. In the next step, a free PP2Ac model was built via homology re-modeling of the PP1c template and the same four sequences were docked to it. Thus, together, 20 starting model complexes were built, allowing for combination of the Zno and Mno pseudo-molecules, free enzymes and the peptide ligands docked in the catalytic sites of PP1c and PP2Ac. All models were subsequently subjected to 250-300 ps molecular dynamics using the AMBER 5.0 program. The equilibrated trajectories of the final 50 ps were taken for further analyses. The theoretical models of PP1c complexes, irrespective of the dication type, exhibited increased mobilities in the following residue ranges: 195-200, 273-278, 287-209 for the inhibitor sequences and 21-25, 194-200, 222-227, 261, 299-302 for the substrate sequences. Paradoxically, the analogous PP2Ac models appeared much more stable in similar simulations, since only their "prosegment" residues 6-10 and 14-18 exhibited an increased mobility in the inhibitor complexes while no areas of increased mobility were found in the substrate complexes. Another general observation was that the complexes with Mn dications were more stable than those with Zn dications for both PP1c and PP2Ac units.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 35-52
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies