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Wyniki wyszukiwania dla: Jacek Czub
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Dominant Pathways of Adenosyl Radical-Induced DNA Damage Revealed by QM/MM Metadynamics
PublikacjaBrominated nucleobases sensitize double stranded DNA to hydrated electrons, one of the dominant genotoxic species produced in hypoxic cancer cells during radiotherapy. Such radiosensitizers can therefore be administered locally to enhance treatment efficiency within the solid tumor while protecting the neighboring tissue. When a solvated electron attaches to 8-bromoadenosine, a potential sensitizer, the dissociation of bromide...
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How acidic amino acid residues facilitate DNA target site selection
PublikacjaDespite the negative charge of the DNA backbone, acidic residues (Asp/Glu) commonly participate in the base readout, with a strong preference for cytosine. In fact, in the solved DNA/protein structures, cytosine is recognized almost exclusively by Asp/Glu through a direct hydrogen bond, while at the same time, adenine, regardless of its amino group, shows no propensity for Asp/Glu. Here, we analyzed the contribution of Asp/Glu...
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Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublikacjaSmall heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as...
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Correlation between the number of Pro-Ala repeats in the EmrA homologue of Acinetobacter baumannii and resistance to netilmicin, tobramycin, imipenem and ceftazidime
PublikacjaAcinetobacter baumannii coccobacilli are dangerous to patients in intensive care units because of their multidrug resistance to antibiotics, developed mainly in the past decade. This study aimed to examine whether there is a significant correlation between the number of Pro-Ala repeats in the CAP01997 protein, the EmrA homologue of A. baumannii, and resistance to antibiotics. A total of 79 multidrug-resistant A. baumannii strains...
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Interaction of cisplatin and two potential antitumoral platinum(ii) complexes with a model lipid membrane: a combined NMR and MD study
PublikacjaIn this study, the interaction of cisplatin (1) and two potential antitumoral Pt(II) complexes (2 and 3) with a model DMPC bilayer was investigated by multinuclear NMR spectroscopy and MD simulations in order to understand its implication for the different antitumoral properties shown by the three complexes. In particular, 31P, 13C and 2H solid state NMR experiments were performed to obtain information on the phase structure, phase...
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Guanosine Dianions Hydrated by One to Four Water Molecules
PublikacjaIntermolecular interactions such as those present in molecule···water complexes may profoundly influence the physicochemical properties of molecules. Here, we carried out an experimental–computational study on doubly deprotonated guanosine monophosphate···water clusters, [dGMP – 2H]2–·nH2O (n = 1–4), using a combination of negative anion photoelectron spectroscopy (NIPES) with molecular dynamics (MD) and quantum chemical (QM) calculations....
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Localization and Orientation of Xanthophylls in a Lipid Bilayer
PublikacjaXanthophylls (polar carotenoids) play diverse biological roles, among which are modulation of the physical properties of lipid membranes and protection of biomembranes against oxidative damage. Molecular mechanisms underlying these functions are intimately related to the localization and orientation of xanthophyll molecules in lipid membranes. In the present work, we address the problem of localization and orientation of two xanthophylls...
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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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Self-Association of Amphotericin B: Spontaneous Formation of Molecular Structures Responsible for the Toxic Side Effects of the Antibiotic
PublikacjaAmphotericin B (AmB) is a lifesaving antibiotic used to treat deep-seated mycotic infections. Both the pharmaceutical activity and highly toxic side effects of the drug rely on its interaction with biomembranes, which is governed by the molecular organization of AmB. In the present work we present detailed analysis of self-assembly of AmB molecules in different environments, interesting from the physiological standpoint, based...
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Self-assembly, stability and conductance of amphotericin B channels: bridging the gap between structure and function
PublikacjaAmphotericin B (AmB), one of the most powerful but also toxic drugs used to treat systemic mycoses, is believed to selectively permeabilize fungal cell membranes to ions in a sterol-dependent manner. Unfortunately, the structure of the biologically active AmB channels has long eluded researchers, obstructing the design of safer alternatives. Here, we investigate the structural and thermodynamic aspects of channel formation, stability,...
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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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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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Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives
PublikacjaIt is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest–CD interactions, rendering structure-based prediction of the complexation efficiency with...
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Iron–Sulfur Cluster Biogenesis Chaperones: Evidence for Emergence of Mutational Robustness of a Highly Specific Protein–Protein Interaction
PublikacjaBiogenesis of iron–sulfur clusters (FeS) is a highly conserved process involving Hsp70 and J-protein chaperones. However, Hsp70 specialization differs among species. In most eukaryotes, including Schizosaccharomyces pombe, FeS biogenesis involves interaction between the J-protein Jac1 and the multifunctional Hsp70 Ssc1. But, in Saccharomyces cerevisiae and closely related species, Jac1 interacts with the specialized Hsp70 Ssq1,...
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Role of the disulfide bond in stabilizing and folding of the fimbrial protein DraE from uropathogenic Escherichia coli
PublikacjaDr fimbriae are homopolymeric adhesive organelles of uropathogenic Escherichia coli composed of DraE subunits, responsible for the attachment to host cells. These structures are characterized by enormously high stability resulting from the structural properties of an Ig-like fold of DraE. One feature of DraE and other fimbrial subunits that makes them peculiar among Ig-like domain-containing proteins is a conserved disulfide bond...
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Triplet–Triplet Annihilation Upconverting Liposomes: Mechanistic Insights into the Role of Membranes in Two-Dimensional TTA-UC
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Two-step mechanism of J-domain action in driving Hsp70 function
PublikacjaJ-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s...
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Structure and evolution of the 4-helix bundle domain of Zuotin, a J-domain protein co-chaperone of Hsp70
PublikacjaThe J-domain protein Zuotin is a multi-domain eukaryotic Hsp70 co-chaperone. Though it is primarily ribosome-associated, positioned at the exit of the 60S subunit tunnel where it promotes folding of nascent polypeptide chains, Zuotin also has off-ribosome functions. Domains of Zuotin needed for 60S association and interaction with Hsp70 are conserved in eukaryotes. However, whether the 4-helix bundle (4HB) domain is conserved remains...
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Enhancing colloidal stability of nanodiamond via surface modification with dendritic molecules for optical sensing in physiological environments
PublikacjaPre-treatment of diamond surface in low-temperature plasma for oxygenation and in acids for carboxylation was hypothesized to promote the branching density of the hyperbranched glycidol polymer. This was expected to increase the homogeneity of the branching level and suppress interactions with proteins. As a result, composite nanodiamonds with reduced hydrodynamic diameters that are maintained in physiological environments were...
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Triplet–Triplet Annihilation Upconverting Liposomes: Mechanistic Insights into the Role of Membranes in Two-Dimensional TTA-UC
PublikacjaTriplet−triplet annihilation upconversion (TTA-UC) implemented in nanoparticle assemblies is of emerging interest in biomedical applications, including in drug delivery and imaging. As it is a bimolecular process, ensuring sufficient mobility of the sensitizer and annihilator to facilitate effective collision in the nanoparticle is key. Liposomes can provide the benefits of two-dimensional confinement and condensed concentration...
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Analysis of Reconstituted Tripartite Complex Supports Avidity-based Recruitment of Hsp70 by Substrate Bound J-domain Protein
PublikacjaHsp70 are ubiquitous, versatile molecular chaperones that cyclically interact with substrate protein(s). The initial step requires synergistic interaction of a substrate and a J-domain protein (JDP) cochaperone, via its J-domain, with Hsp70 to stimulate hydrolysis of its bound ATP. This hydrolysis drives conformational changes in Hsp70 that stabilize substrate binding. However, because of the transient nature of substrate and JDP...
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Defining a novel domain that provides an essential contribution to site-specific interaction of Rep protein with DNA
PublikacjaAn essential feature of replication initiation proteins is their ability to bind to DNA. In this work, we describe a new domain that contributes to a replication initiator sequence-specific interaction with DNA. Applying biochemical assays and structure prediction methods coupled with DNA–protein crosslinking, mass spectrometry, and construction and analysis of mutant proteins, we identified that the replication initiator of the...
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Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye
PublikacjaThe functioning of the human eye in the extreme range of light intensity requires a combination of the high sensitivity of photoreceptors with their photostability. Here, we identify a regulatory mechanism based on dynamic modulation of light absorption by xanthophylls in the retina, realized by reorientation of pigment molecules induced by trans–cis photoisomerization. We explore this photochemically switchable system using chromatographic...
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Sequence-dependent structural properties of B-DNA: what have we learned in 40 years?
PublikacjaThe structure of B-DNA, the physiological form of the DNA molecule, has been a central topic in biology, chemistry and physics. Far from uniform and rigid, the double helix was revealed as a flexible and structurally polymorphic molecule. Conformational changes that lead to local and global changes in the helix geometry are mediated by a complex choreography of base and backbone rearrangements affecting the ability of the B-DNA...
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Computer science 2024
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Initial geometries and MD trajectories of right- and left-handed G-quadruplexes
Dane BadawczeDataset contains initial geometries of 12 monomeric, 2-tetrad G-quadruplexes featuring three different loop lengths (T1, T2 and T3), adapted by the sequence GGTnGGTnGGTnGG where n=(1-3). For each loop length variant two directions of strand progression (clockwise (+) and anti-clockwise (-)) and two helicities (left-handed (LH) and right-handed (RH))...
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Physical Chemistry GT 2022/23 Summer
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Podstawy chemii fizycznej i biofizycznej -- ćwiczenia
Kursy OnlineCelem przedmiotu jest dostarczenie formalizmu służącego do opisu i przewidywania przebiegu reakcji biochemicznych oraz innych procesów biomolekularnych. Plan kursu: 1. Oddziaływania międzycząsteczkowe (elektrostatyka, oddziały-wania van der Waalsa, wiązania wodorowe, oddziaływania hydro-fobowe) 2. Podstawy termodynamiki z elementami teorii statystycznej (zasady termodynamiki, entropia i jej interpretacja statystyczna, rozkład...
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Podstawy chemii fizycznej i biofizycznej -- wykład
Kursy OnlineCelem przedmiotu jest dostarczenie formalizmu służącego do opisu i przewidywania przebiegu reakcji biochemicznych oraz innych procesów biomolekularnych. Plan kursu: 1. Oddziaływania międzycząsteczkowe (elektrostatyka, oddziały-wania van der Waalsa, wiązania wodorowe, oddziaływania hydro-fobowe) 2. Podstawy termodynamiki z elementami teorii statystycznej (zasady termodynamiki, entropia i jej interpretacja statystyczna, rozkład...
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Chemia Fizyczna Biotechnologia sem III 2023/2024
Kursy OnlineCelem przedmiotu jest poznanie praw fizycznych rządzących przemianami (bio)chemicznymi i dostarczenie narzędzi teoretycznych pozwalających na opis i przewidywanie tych przemian.
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Chemia Fizyczna Biotechnologia sem III 2024/2025
Kursy OnlineCelem przedmiotu jest poznanie praw fizycznych rządzących przemianami (bio)chemicznymi i dostarczenie narzędzi teoretycznych pozwalających na opis i przewidywanie tych przemian.
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Molekularny mechanizm sprzężenia mechanochemicznego w syntazie ATP jako punkt wyjścia do opracowania nowych leków przeciwdrobnoustrojowych
ProjektyProjekt realizowany w Katedra Chemii Fizycznej zgodnie z porozumieniem UMO-2017/26/E/NZ2/00472 z dnia 2018-04-09
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- Telomeres as targets for anticancer drug development - a computational approach
ProjektyProjekt realizowany w Wydział Chemiczny zgodnie z porozumieniem Homing Plus/2011-4/3 z dnia 2012-03-29
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Molekularny mechanizm transferu i konwersji energii w katalitycznej części syntazy ATP
ProjektyProjekt realizowany w Katedra Chemii Fizycznej zgodnie z porozumieniem Umowa nr 0304/IP3/2013/72 z dnia 2013-06-19
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Molekularny mechanizm wpływu stresu oksydacyjnego na stabilność strukturalną i dynamikę kompleksów telomerowego DNA z białkami
ProjektyProjekt realizowany w Katedra Chemii Fizycznej zgodnie z porozumieniem 0059/DIA/2014/43 z dnia 2014-09-18
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Konstrukty PROTAC zdolne do eliminacji nadmiaru białek amyloidogennych, ludzkiego polipeptydu amyloidu wysepek trzustkowych (hIAPP) i ludzkiego osoczowego amyloidu A (hSAA)
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Badanie zależności pomiędzy sekwencją DNA a strukturą jako punkt wyjścia do projektowania G-kwadrupleksów o określonej topologii -- zintegrowane podejście łączące symulacje molekularne i metody eksperymentalne
ProjektyProjekt realizowany w Katedra Chemii Fizycznej zgodnie z porozumieniem UMO-2019/35/B/ST4/03559 z dnia 2020-06-19
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KatedrA Chemii Fizycznej
Zespoły Badawcze1.Termodynamika i struktura roztworów, oddziaływania międzycząsteczkowe w roztworach - badania termodynamiczne, spektroskopowe i teoretyczne. 2. Fizykochemiczne podstawy analizy środowiskowej.
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Best Practices in Monitoring
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Deep sea habitats in the chemical warfare dumping areas of the Baltic Sea
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Exposure status of sea-dumped chemical warfare agents in the Baltic Sea
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Ze świata Lean: Lean w Polsce, ale po japońsku
WydarzeniaZapraszamy na kolejne spotkanie z cyklu Ze świata Lean. Gościem będzie Ewelina Gierek-Czub – continuous Improvement chief specialist in Daicel Safety Systems Europe sp. z o.o.
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CALIBRATION OF LOW ENERGY X-RAY EXPERIMENTAL SETUP WITH STRONGLY FILTERED BEAM USING DATA FROM A SEMICONDUCTOR AND A THERMOLUMINESCENT DETECTORS
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