3,986 results match your criteria: "Institute of Organic Chemistry and Biochemistry[Affiliation]"

CryptoBench: Cryptic protein-ligand binding sites dataset and benchmark.

Bioinformatics

December 2024

Department of Software Engineering, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.

Motivation: Structure-based methods for detecting protein-ligand binding sites play a crucial role in various domains, from fundamental research to biomedical applications. However, current prediction methodologies often rely on holo (ligand-bound) protein conformations for training and evaluation, overlooking the significance of the apo (ligand-free) states. This oversight is particularly problematic in the case of cryptic binding sites (CBSs) where holo-based assessment yields unrealistic performance expectations.

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4-Oxo-β-lactams as Covalent Inhibitors of the Mitochondrial Intramembrane Protease PARL.

ACS Med Chem Lett

December 2024

Laboratory of Chemical Biology, Department of Cellular and Molecular Medicine, KU Leuven - University of Leuven, Herestraat 49 box 901b, 3000 Leuven, Belgium.

Rhomboid proteases play a variety of physiological roles, but rhomboid protease inhibitors have been mostly developed for the model rhomboid GlpG. In this work, we screened different electrophilic scaffolds against the human mitochondrial rhomboid PARL and found 4-oxo-β-lactams as submicromolar inhibitors. Multifaceted computations suggest explanations for the activity at the molecular scale and provide models of covalently bound complexes.

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We report a study of internal covalent cross-linking with photolytically generated diarylnitrile imines of N-terminal arginine, lysine, and histidine residues in peptide conjugates. Conjugates in which a 4-(2-phenyltetrazol-5-yl)benzoyl group was attached to C-terminal lysine, that we call RAAA--K, KAAA--K, and HAAA--K, were ionized by electrospray and subjected to UV photodissociation (UVPD) at 213 nm. UVPD triggered loss of N and proceeded by covalent cross-linking to nitrile imine intermediates that involved the side chains of N-terminal arginine, lysine, and histidine, as well as the peptide amide groups.

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Liver-enriched antimicrobial peptide 2 (LEAP2) is a natural antagonist/inverse agonist of ghrelin receptor GHSR. Its truncated palmitoylated analog palm-LEAP2(1-14) promised anti-obesity properties because it exhibited favourable stability and an acute anorexigenic effect in our previous studies. Here we demonstrate desirable palm-LEAP2(1-14) pharmacokinetics, with significant levels of the peptide persisting in mouse blood 3 hours after its subcutaneous administration.

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SARS-CoV-2 main protease (M) autocatalytically releases itself out of the viral polyprotein to form a fully active mature dimer in a manner that is not fully understood. Here, we introduce several tools to help elucidate differences between cis (intramolecular) and trans (intermolecular) proteolytic processing and to evaluate inhibition of precursor M. We found that many mutations at the P1 position of the N-terminal autoprocessing site do not block cis autoprocessing but do inhibit trans processing.

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The PB2 subunit of the influenza virus polymerase complex is essential for viral replication, primarily through a mechanism known as cap-snatching. In this process, PB2 binds to the 5' cap structure of host pre-mRNAs, enabling the viral polymerase to hijack the host transcriptional machinery. This binding facilitates the cleavage and integration of the capped RNA fragment into viral mRNA, thereby promoting efficient viral replication.

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Prodrugging fungicidal amphotericin B significantly decreases its toxic effects.

Eur J Med Chem

December 2024

Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, Prague, 128 00, Czech Republic; Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo Nám. 542/2, Prague, 160 00, Czech Republic. Electronic address:

Amphotericin B (AmB) is one of the most effective antifungal drugs, with a strong, dose-dependent activity against most Candida and Aspergillus species responsible for life-threatening infections. However, AmB is severely toxic, which hinders its broad use. In this proof-of-concept study, we demonstrate that prodrugging AmB considerably decreases AmB toxicity without affecting its fungicidal activity.

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Lipid Demixing Reduces Energy Barriers for High Curvature Vesicle Budding.

Biophys J

December 2024

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16000 Prague 6, Czech Republic; Institute of Chemistry, the Fritz Haber Research Center, and the Harvey M. Kruger Center for Nanoscience & Nanotechnology, The Hebrew University, Jerusalem 9190401, Israel. Electronic address:

Under standard physiological conditions, budding relies on asymmetries, including differences in leaflet composition, area, and osmotic conditions, and involves large curvature changes in nanoscale lipid vesicles. So far, the combined impact of asymmetry and high curvatures on budding has remained unknown. Here, using continuum elastic theory, the budding pathway is detailed under realistic conditions.

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CaMKIIα hub ligands are unable to reverse known phenotypes in Angelman syndrome mice.

Basic Clin Pharmacol Toxicol

January 2025

Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.

Angelman Syndrome (AS) is a neurodevelopmental disorder caused by the loss of function of ubiquitin-protein ligase E3A (UBE3A), resulting in marked changes in synaptic plasticity. In AS mice, a dysregulation of Ca/calmodulin-dependent protein kinase II alpha (CaMKIIα) was previously described. This has been convincingly validated through genetic rescue of prominent phenotypes in mouse cross-breeding experiments.

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Reduced Radial Electric Quadrupole Moment Function for Diatomic Molecules.

J Chem Theory Comput

December 2024

Institute of Organic Chemistry and Biochemistry, p.r.i., Czech Academy of Sciences, Flemingovo nám. 2 Prague 6, Praha 166 10, Czechia.

The prospect of constructing global electric quadrupole moment functions (EQMFs) of diatomic molecules by morphing their theoretical approximants within the framework of the reduced radial curve (RRC) approach is explored by performing model calculations for the ground electronic states of H and HF. The reduced quadrupole moment curves probed, constructed for a set of differently accurate theoretical EQMFs, coincide with their best many-parameter analytic counterparts so closely that they can be used as their accurate few-parameter representations. No other such functional representation is available in the literature.

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Intensive agricultural practices impact the health and nutrition of pollinators like honey bees (). Rapeseed ( L.) is widely cultivated, providing diverse nutrients and phytochemicals, including -methyl-L-cysteine sulfoxide (SMCSO).

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The antioxidant activity of Scorzonera parviflora Jacq. roots were assessed by measuring their ability to scavenge ABTS and DPPH radicals. Bioactivity-guided fractionation was utilized to identify the compound(s) responsible for this activity.

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Vicinal Bis(methylene) Heterocyclic Diene in Natural Product Synthesis: A Convergent Biomimetic Total Synthesis of Prunolactone A.

Org Lett

December 2024

Department of Organic and Bioorganic Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.

The first total syntheses of the natural isocoumarin prunolactone A with a 6/6/6/6/6 spiropentacyclic skeleton and its unnatural (3')-epimer in 10 and 8 steps, respectively, are reported. The syntheses feature generation of a reactive 3,4-bis(methylene)isocoumarin intermediate, its biomimetic Diels-Alder reactions with the shikimic-acid-derived scytolide and (8)-scytolide, and a Mitsunobu reaction allowing access to scytolide in a stereochemically pure form. Computational support for the selectivity of the Diels-Alder reaction is provided.

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For drugs to be active they have to reach their targets. Within cells this requires crossing the cell membrane, and then free diffusion, distribution, and availability. Here, we explored the in-cell diffusion rates and distribution of a series of small molecular fluorescent drugs, in comparison to proteins, by microscopy and fluorescence recovery after photobleaching (FRAP).

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Non-healing wounds are a serious complication in diabetic patients. One of the detrimental factors contributing to limited wound healing is the accumulation of metalloproteinase-9 (MMP-9) in the wound. Selective inhibition of MMP-9 is one of the established therapeutic targets for diabetic wound healing.

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Accelerating the rotational speed of light-driven molecular motors is among the foremost concerns in molecular machine research, as this speed directly influences the performance of a motor. Controlling the motor's rotation is crucial for practical applications, and using an oriented external electric field (OEEF) represents a feasible method to achieve this objective. We have investigated the impact of an OEEF on the optical and kinetic properties of a novel π-donor/acceptor di-substituted molecular motor, R2,3-(NH2, CHO).

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Transition to the memory safe natively compiled programming languages is a major software development trend in recent years, which eliminates memory-related security exploits, enables a fearless concurrency and parallelization, and drastically improves ergonomics and speed of software development. Modern memory-safe programing languages, such as Rust, are currently not used for developing molecular modeling and simulation software despite such obvious benefits as faster development cycle, better performance and smaller amount of bugs. This work introduces MolAR-the first memory-safe library for analysis of MD simulations written in Rust.

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Article Synopsis
  • Sulfated cyclodextrins are negatively charged molecules used in capillary electrophoresis for separating chiral compounds, but their effective charge can be lower than expected due to counterion binding.
  • This study used capillary isotachophoresis and capillary zone electrophoresis to measure the effective charge numbers and ionic mobilities of two types of sulfated cyclodextrins: single isomer and randomly highly sulfated.
  • Results showed that while the effective charge numbers of single isomer sulfated cyclodextrins closely matched their sulfate groups, the randomly highly sulfated versions had their effective charges reduced by 22.2%-27.8%, leading to lower ionic mobilities for the single isomer
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A DNA sequence pattern, or "motif", is an essential representation of DNA-binding specificity of a transcription factor (TF). Any particular motif model has potential flaws due to shortcomings of the underlying experimental data and computational motif discovery algorithm. As a part of the Codebook/GRECO-BIT initiative, here we evaluated at large scale the cross-platform recognition performance of positional weight matrices (PWMs), which remain popular motif models in many practical applications.

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Identification of methylation-sensitive human transcription factors using meSMiLE-seq.

bioRxiv

November 2024

Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

Transcription factors (TFs) are key players in eukaryotic gene regulation, but the DNA binding specificity of many TFs remains unknown. Here, we assayed 284 mostly poorly characterized, putative human TFs using selective microfluidics-based ligand enrichment followed by sequencing (SMiLE-seq), revealing 72 new DNA binding motifs. To investigate whether some of the 158 TFs for which we did not find motifs preferably bind epigenetically modified DNA (i.

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Homeostasis of cellular membranes is maintained by fine-tuning their lipid composition. Yeast lipid transporter Osh6, belonging to the oxysterol-binding protein-related proteins family, was found to participate in the transport of phosphatidylserine (PS). PS synthesized in the endoplasmic reticulum is delivered to the plasma membrane, where it is exchanged for phosphatidylinositol 4-phosphate (PI4P).

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Peptide conjugates furnished with a 2,5-diaryltetrazolecarbonyl tag at the C-terminal lysine, which we call peptide--K, were found to undergo efficient cross-linking of Asp, Glu, Asn, and Gln residues to transient nitrile-imine intermediates produced by photodissociation and collision-induced dissociation (CID) of the tetrazole ring in gas-phase ions. UV photodissociation (UVPD) at 213 nm achieved cross-linking conversion yields of 37 and 61% for DAAAK--K and EAAAK--K, respectively. The yields for NAAAK--K and QAAAK--K were 29 and 57%, respectively.

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Diazidodifluoromethane was prepared from dibromodifluoromethane, sodium azide and an alkanethiolate initiator. It represents the first example of a diazidomethane that is stable enough to be used in synthesis. The stability of (poly)azidomethanes was explored with calculations.

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