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Development of pharmacophore-guided molecular docking protocol for design of SARS-CoV-2 main protease inhibitors
Klenor, Mikuláš ; Lepšík, Martin (advisor) ; Riedlová, Kamila (referee)
Covid-19 is a highly contagious potentially life-threatening disease caused by the SARS-CoV-2 coronavirus. The virus is responsible for a global pandemic and has claimed over 6 million human lives between years 2020 and 2022. To limit the spread of SARS-CoV-2, numerous vaccines have been developed and applied. For already infected individuals, antiviral drugs are applied. An important validated target is the main protease of SARS-CoV-2 (Mpro ). Although thousands of inhibitors have been prepared and one is used in clinical practice (sold under the name of Paxlovid), improved computational protocols to design new active compounds are needed. The computational approach used here is based on pharmacophores. By curating and inspecting 298 structures of Mpro /inhibitors complexes retrieved from the Protein Data Bank (PDB), we have generated six distinct pharmacophores featuring different binding modes. With their aid, we have carried out molecular docking, whose effectiveness was evaluated by measuring root-mean-square deviation (RMSD) of the generated poses with respect to the native conformations. The routine captured 177 out of 213 ligands naturally binding to the active site of the protein with 127 (72% of the captured) generated with RMSD within 2 Å relative to the native conformation....
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Therapeutic use of alternative protein binders targeting tumor biomarkers in clinical testing of oncology patients
Tauš, Petr ; Drbal, Karel (advisor) ; Lepšík, Martin (referee)
Almost until the end of the last century, antibodies (aka immunoglobulins) were considered the only class of specific binding proteins. The discovery of hybridoma technology in 1975 had enabled the production of monoclonal antibodies and after twenty years some of them have entered clinical practice. Meanwhile, the first non-immunoglobulin protein scaffold, in which new specific binding sites could be introduced was discovered. To date, many different alternative scaffolds have been described, but only a few of them are being further developed for diagnostics, therapeutics or tools in basic research. Since these structures are overcoming the drawbacks of immunoglobulin structure, which are big size, expensive production and difficult rational design, they have potential to replace and exceed them. In this bachelor's thesis all the alternative scaffolds in development are summarized. Moreover, their advancements in clinical trials are described and compared with approved therapeutics based on immunoglobulin structure.
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The role of DNA minor groove deformation in specific recognition of DNA by proteins
Faltejsková, Kateřina ; Vondrášek, Jiří (advisor) ; Lepšík, Martin (referee)
The specific recognition of the DNA is crucial for the correct functioning of the cell. Although its mechanisms are extensively studied, the actual process is not yet fully understood, partly due to the variance observed in readout mechanisms so far. In this work, a particular type of specific recognition is examined: the shape readout in the DNA minor groove. Based on a sta- tistical analysis of three-dimensional structures of protein-DNA complexes acquired from the Protein Data Bank, I propose a previously unrecorded readout mechanism of widened minor grooves by hydrophobic amino acids. In addition, the effect of DNA sequence on the topography of the contacted locus, the preferred secondary structures and the interaction between the protein and DNA are explored, as well as the relative information amount of examined features concerning the DNA deformation. 1
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Modelling Binding of Insulin Variants toward Insulin Receptor Based on Recent Structural Breakthroughs
Černeková, Michaela ; Lepšík, Martin (advisor) ; Biedermannová, Lada (referee)
Insulin receptor is a multi-domain signalling protein acting as a dimer. It comprises an extracellular ectodomain, a transmembrane domain and intracellular tyrosine kinase domain. Upon insulin binding, conformational changes in insulin as well as in insulin receptor occur and trigger the signaling cascade via the kinase domain. Abnormalities in insulin and insulin receptor function cause diabetes mellitus, a widespread disorder which can be consequence of genetic factors as well as lifestyle and is manifested by increased level of blood glucose. A common treatment of diabetes mellitus is via insulin analogues with different molecular properties. Insulin/insulin receptor interactions in the binding pocket are divided into two groups, so-called "site1" and "site2". The molecular details of the interactions in site1 are well known, while site2 residues are still not completely elucidated. It is important to shed light on the binding properties of insulin and insulin receptor, especially site2 interactions, because it could contribute to improved design of new insulin analogues. In this work, we used the very recent breakthroughs in the structural biology of insulin receptor to study the interactions by computational chemistry methods. It was thus possible to assess the noncovalent interactions and...
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Nonclassical noncovalent interactions in proteins and their importance for design of novel specific viral enzyme inhibitors
Kříž, Kristian ; Lepšík, Martin (advisor) ; Novotný, Marian (referee) ; Kabeláč, Martin (referee)
Noncovalent interactions are vital for functioning of biological systems. For instance, they facilitate DNA base pairing or protein folding. Recently, in addition to classical noncovalent interactions such as hydrogen bond, nonclassical noncovalent interactions have been discovered. An example of these interactions is halogen bond belonging to the class of σ-hole interactions, the knowledge of which is already being useful for medical compound design. The aim of this work is to find out if the chalcogen bond, also a σ-hole interaction, plays a role in the binding of existing viral inhibitors, too. Following that, we are also interested whether or to what extent can these existing chalcogen bonds be optimized for a greater affinity of the inhibitor binding. Several protein-ligand crystal structures exhibiting geometrical properties favoring a chalcogen bond have been found in the PDB database. We examined the interaction energies and the interaction energy geometrical dependencies of model systems derived from these crystal structures by means of quantum chemical calculations. Further we have optimized their strength by a series of substitutions. We thus propose that chalcogen bond can become a player in rational design of inhibitors of viral enzymes and their protein target. Keywords: Noncovalent...
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Therapeutic use of alternative protein binders targeting tumor biomarkers in clinical testing of oncology patients
Tauš, Petr ; Drbal, Karel (advisor) ; Lepšík, Martin (referee)
Almost until the end of the last century, antibodies (aka immunoglobulins) were considered the only class of specific binding proteins. The discovery of hybridoma technology in 1975 had enabled the production of monoclonal antibodies and after twenty years some of them have entered clinical practice. Meanwhile, the first non-immunoglobulin protein scaffold, in which new specific binding sites could be introduced was discovered. To date, many different alternative scaffolds have been described, but only a few of them are being further developed for diagnostics, therapeutics or tools in basic research. Since these structures are overcoming the drawbacks of immunoglobulin structure, which are big size, expensive production and difficult rational design, they have potential to replace and exceed them. In this bachelor's thesis all the alternative scaffolds in development are summarized. Moreover, their advancements in clinical trials are described and compared with approved therapeutics based on immunoglobulin structure.
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Vazba fenylnorstatinového inhibitoru na proteázu HIV-1: geometrie, protonace a interakce kapes podřadných míst analyzované při atomovém rozlišení
Brynda, Jiří ; Řezáčová, Pavlína ; Fábry, Milan ; Hořejší, Magdalena ; Štouračová, Renata ; Sedláček, Juraj ; Souček, Milan ; Hradilek, Martin ; Lepšík, Martin ; Konvalinka, Jan
The x-ray structure of a complex of HIV-1 protease (PR) with a phenylnorstatine inhibitor Z-Pns-Phe-Glu-Glu-NH2 has been determined at 1.03 A, the highest resolution so far reported for any HIV PR complex. The inhibiot shows subnanomolar Ki values for both the wild-type PR and the variant representing one of the most common mutations linked to resistance development. The structure displays a unique pattern of hydrogen bonding to the two catalytic aspartate residues. The high resolution permints to assess the donor/acceptor relations of this hydrogen bonding and to indicate a proton shared by the two catalytic residues. Structural mechanism for the unimpaired inhibition of the protease Val82Ala mutant is also suggested, based on energy calculations and analyses
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