Publications by authors named "Alexey Ishchenko"

The influence of Eu doping (0.5, 1 and 2 mol.%) and annealing in an oxygen-deficient atmosphere on the structure and optical properties of SnO nanoparticles were investigated in relation to electronic structure.

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Samples of ZrO ceramics with different concentrations of impurity titanium ions were synthesized by mixing zirconium and titanium oxide powders in different mass ratios. The X-ray diffraction analysis was used to determine the phase composition, lattice parameters, and crystallite size of the ceramics with varying dopant concentrations. Upon irradiation of the samples with 220 MeV Xe ions to a fluence of 10 ions/cm, a decrease in the intensity of the pulsed cathodoluminescence band at 2.

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Gd and Sm co-activation, the effect of cation substitutions and the creation of cation vacancies in the scheelite-type framework are investigated as factors influencing luminescence properties. AgGdSmEu☐WO ( = 0.50, 0.

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Although seeking to develop a general and accurate binding free energy calculation method for protein-protein and protein-ligand interactions has been a continuous effort for decades, only limited successes have been obtained so far. Here, we report the development of a metadynamics-based procedure that calculates Dissociation Free Energy (DFE) and its application to 19 non-congeneric protein-protein complexes and hundreds of protein-ligand complexes covering eight targets. We achieved very high correlations in comparison to experimental binding free energies for these diverse sets of systems, demonstrating the generality and accuracy of the method.

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Inhibiting protein function selectively is a major goal of modern drug discovery. Here, we report a previously understudied benefit of small molecule proteolysis-targeting chimeras (PROTACs) that recruit E3 ubiquitin ligases to target proteins for their ubiquitination and subsequent proteasome-mediated degradation. Using promiscuous CRBN- and VHL-recruiting PROTACs that bind >50 kinases, we show that only a subset of bound targets is degraded.

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PIM kinases are implicated in variety of cancers by promoting cell survival and proliferation and are targets of interest for therapeutic intervention. We have identified a low-nanomolar pan-PIM inhibitor (PIM1/2/3 potency 5:14:2nM) using structure based modeling. The crystal structure of this compound with PIM1 confirmed the predicted binding mode and protein-ligand interactions except those in the acidic ribose pocket.

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It is well-known that the structure-based design approach has had a measurable impact on the drug discovery process in identifying novel and efficacious therapeutic agents for a variety of disease targets. The de novo design approach has inherent potential to generate novel molecules that best fit into a protein binding site when compared to all of the computational methods applied to structure-based design. In its initial attempts, this approach did not achieve much success due to technical hurdles.

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Structure guided optimization of a series of nonpeptidic alkyl amine renin inhibitors allowed the rational incorporation of additional polar functionality. Replacement of the cyclohexylmethyl group occupying the S1 pocket with a (R)-(tetrahydropyran-3-yl)methyl group and utilization of a different attachment point led to the identification of clinical candidate 9. This compound demonstrated excellent selectivity over related and unrelated off-targets, >15% oral bioavailability in three species, oral efficacy in a double transgenic rat model of hypertension, and good exposure in humans.

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Structure-based design led to the discovery of a novel class of renin inhibitors in which an unprecedented phenyl ring filling the S1 site is attached to the phenyl ring filling the S3 pocket. Optimization for several parameters including potency in the presence of human plasma, selectivity against CYP3A4 inhibition and improved rat oral bioavailability led to the identification of 8d which demonstrated antihypertensive efficacy in a transgenic rat model of human hypertension.

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Structure-guided drug design led to new alkylamine renin inhibitors with improved in vitro and in vivo potency. Lead compound 21a, has an IC(50) of 0.83nM for the inhibition of human renin in plasma (PRA).

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Structure-based drug design led to the identification of a novel class of potent, low MW alkylamine renin inhibitors. Oral administration of lead compound 21l, with MW of 508 and IC(50) of 0.47nM, caused a sustained reduction in mean arterial blood pressure in a double transgenic rat model of hypertension.

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Computational lead design procedures require fast and accurate scoring functions to rank millions of generated virtual ligands for protein targets. In this article, we present an improved version of the SMoG scoring function, called SMoG2001. This function is based on a knowledge-based approach-that is, the free energy parameters are derived from the observed frequencies of atom-atom contacts in the database of three-dimensional structures of protein-ligand complexes via a procedure based on statistical mechanics.

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Computational methods are becoming increasingly used in the drug discovery process. In this Account, we review a novel computational method for lead discovery. This method, called CombiSMoG for "combinatorial small molecule growth", is based on two components: a fast and accurate knowledge-based scoring function used to predict binding affinities of protein-ligand complexes, and a Monte Carlo combinatorial growth algorithm that generates large numbers of low-free-energy ligands in the binding site of a protein.

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Combinatorial small molecule growth algorithm was used to design inhibitors for human carbonic anhydrase II. Two enantiomeric candidate molecules were predicted to bind with high potency (with R isomer binding stronger than S), but in two distinct conformations. The experiments verified that computational predictions concerning the binding affinities and the binding modes were correct for both isomers.

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