1. |
- Allison, Timothy M., et al.
(author)
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Complementing machine learning‐based structure predictions with native mass spectrometry
- 2022
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In: Protein Science. - : John Wiley & Sons. - 0961-8368 .- 1469-896X. ; 31:6
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Journal article (peer-reviewed)abstract
- The advent of machine learning-based structure prediction algorithms such as AlphaFold2 (AF2) and RoseTTa Fold have moved the generation of accurate structural models for the entire cellular protein machinery into the reach of the scientific community. However, structure predictions of protein complexes are based on user-provided input and may require experimental validation. Mass spectrometry (MS) is a versatile, time-effective tool that provides information on post-translational modifications, ligand interactions, conformational changes, and higher-order oligomerization. Using three protein systems, we show that native MS experiments can uncover structural features of ligand interactions, homology models, and point mutations that are undetectable by AF2 alone. We conclude that machine learning can be complemented with MS to yield more accurate structural models on a small and large scale.
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2. |
- Caraballo, Rémi, et al.
(author)
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Triazole linker-based trivalent sialic acid inhibitors of adenovirus type 37 infection of human corneal epithelial cells
- 2015
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In: Organic and biomolecular chemistry. - 1477-0520 .- 1477-0539. ; 13:35, s. 9194-9205
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Journal article (peer-reviewed)abstract
- Adenovirus type 37 (Ad37) is one of the principal agents responsible for epidemic keratoconjunctivitis (EKC), a severe ocular infection that remains without any available treatment. Recently, a trivalent sialic acid derivative (ME0322, Angew. Chem. Int. Ed., 2011, 50, 6519) was shown to function as a highly potent inhibitor of Ad37, efficiently preventing the attachment of the virion to the host cells and subsequent infection. Here, new trivalent sialic acid derivatives were designed, synthesized and their inhibitory properties against Ad37 infection of the human corneal epithelial cells were investigated. In comparison to ME0322, the best compound (17a) was found to be over three orders of magnitude more potent in a cell-attachment assay (IC50 = 1.4 nM) and about 140 times more potent in a cell-infection assay (IC50 = 2.9nM). X-ray crystallographic analysis demonstrated a trivalent binding mode of all compounds to the Ad37 fiber knob. For the most potent compound ophthalmic toxicity in rabbits was investigated and it was concluded that repeated eye administration did not cause any adverse effects.
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3. |
- Gwon, Yong-Dae, et al.
(author)
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Antiviral Activity of Benzavir-2 against Emerging Flaviviruses
- 2020
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In: Viruses. - : MDPI. - 1999-4915. ; 12:3
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Journal article (peer-reviewed)abstract
- Most flaviviruses are arthropod-borne viruses, transmitted by either ticks or mosquitoes, and cause morbidity and mortality worldwide. They are endemic in many countries and have recently emerged in new regions, such as the Zika virus (ZIKV) in South-and Central America, the West Nile virus (WNV) in North America, and the Yellow fever virus (YFV) in Brazil and many African countries, highlighting the need for preparedness. Currently, there are no antiviral drugs available to treat flavivirus infections. We have previously discovered a broad-spectrum antiviral compound, benzavir-2, with potent antiviral activity against both DNA- and RNA-viruses. Our purpose was to investigate the inhibitory activity of benzavir-2 against flaviviruses. We used a ZIKV ZsGreen-expressing vector, two lineages of wild-type ZIKV, and other medically important flaviviruses. Benzavir-2 inhibited ZIKV derived reporter gene expression with an EC50 value of 0.8 +/- 0.1 µM. Furthermore, ZIKV plaque formation, progeny virus production, and viral RNA expression were strongly inhibited. In addition, 2.5 µM of benzavir-2 reduced infection in vitro in three to five orders of magnitude for five other flaviviruses: WNV, YFV, the tick-borne encephalitis virus, Japanese encephalitis virus, and dengue virus. In conclusion, benzavir-2 was a potent inhibitor of flavivirus infection, which supported the broad-spectrum antiviral activity of benzavir-2.
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4. |
- Horvath, Dragos, et al.
(author)
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Design of a general-purpose European compound screening library for EU-OPENSCREEN
- 2014
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In: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 9:10, s. 2309-2326
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Journal article (peer-reviewed)abstract
- This work describes a collaborative effort to define and apply a protocol for the rational selection of a general-purpose screening library, to be used by the screening platforms affiliated with the EU-OPENSCREEN initiative. It is designed as a standard source of compounds for primary screening against novel biological targets, at the request of research partners. Given the general nature of the potential applications of this compound collection, the focus of the selection strategy lies on ensuring chemical stability, absence of reactive compounds, screening-compliant physicochemical properties, loose compliance to drug-likeness criteria (as drug design is a major, but not exclusive application), and maximal diversity/coverage of chemical space, aimed at providing hits for a wide spectrum of drugable targets. Finally, practical availability/cost issues cannot be avoided. The main goal of this publication is to inform potential future users of this library about its conception, sources, and characteristics. The outline of the selection procedure, notably of the filtering rules designed by a large committee of European medicinal chemists and chemoinformaticians, may be of general methodological interest for the screening/medicinal chemistry community. The selection task of 200K molecules out of a pre-filtered set of 1.4M candidates was shared by five independent European research groups, each picking a subset of 40K compounds according to their own in-house methodology and expertise. An in-depth analysis of chemical space coverage of the library serves not only to characterize the collection, but also to compare the various chemoinformatics-driven selection procedures of maximal diversity sets. Compound selections contributed by various participating groups were mapped onto general-purpose self-organizing maps (SOMs) built on the basis of marketed drugs and bioactive reference molecules. In this way, the occupancy of chemical space by the EU-OPENSCREEN library could be directly compared with distributions of known bioactives of various classes. This mapping highlights the relevance of the selection and shows how the consensus reached by merging the five different 40K selections contributes to achieve this relevance. The approach also allows one to readily identify subsets of target-or target-class-oriented compounds from the EU-OPENSCREEN library to suit the needs of the diverse range of potential users. The final EU-OPENSCREEN library, assembled by merging five independent selections of 40K compounds from various expert groups, represents an excellent example of a Europe-wide collaborative effort toward the common objective of building best-in-class European open screening platforms.
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5. |
- Huerta-Uribe, Alejandro, et al.
(author)
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Identification and Characterization of Novel Compounds Blocking Shiga Toxin Expression in Escherichia coli O157:H7
- 2016
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In: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 7
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Journal article (peer-reviewed)abstract
- Infections caused by Shiga toxin-producing E. coli strains constitute a health problem, as they are problematic to treat. Shiga toxin (Stx) production is a key virulence factor associated with the pathogenicity of enterohaemorrhagic E. coli (EHEC) and can result in the development of haemolytic uremic syndrome in infected patients. The genes encoding Stx are located on temperate lysogenic phages integrated into the bacterial chromosome and expression of the toxin is generally coupled to phage induction through the SOS response. We aimed to find new compounds capable of blocking expression of Stx type 2 (Stx2) as this subtype of Stx is more strongly associated with human disease. High-throughput screening of a small-molecule library identified a lead compound that reduced Stx2 expression in a dose-dependent manner. We show that the optimised compound interferes with the SOS response by directly affecting the activity and oligomerisation of RecA, thus limiting phage activation and Stx2 expression. Our work suggests that RecA is highly susceptible to inhibition and that targeting this protein is a viable approach to limiting production of Stx2 by EHEC. This type of approach has the potential to limit production and transfer of other phage induced and transduced determinants.
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6. |
- Islam, Md. Koushikul, et al.
(author)
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Anti-Rift Valley fever virus activity in vitro, pre-clinical pharmacokinetics and oral bioavailability of benzavir-2, a broad-acting antiviral compound
- 2018
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In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 8
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Journal article (peer-reviewed)abstract
- Rift Valley fever virus (RVFV) is a mosquito-borne hemorrhagic fever virus affecting both humans and animals with severe morbidity and mortality and is classified as a potential bioterror agent due to the possible aerosol transmission. At present there is no human vaccine or antiviral therapy available. Thus, there is a great need to develop new antivirals for treatment of RVFV infections. Benzavir-2 was previously identified as potent inhibitor of human adenovirus, herpes simplex virus type 1, and type 2. Here we assess the anti-RVFV activity of benzavir-2 together with four structural analogs and determine pre-clinical pharmacokinetic parameters of benzavir-2. In vitro, benzavir-2 efficiently inhibited RVFV infection, viral RNA production and production of progeny viruses. In vitro, benzavir-2 displayed satisfactory solubility, good permeability and metabolic stability. In mice, benzavir-2 displayed oral bioavailability with adequate maximum serum concentration. Oral administration of benzavir-2 formulated in peanut butter pellets gave high systemic exposure without any observed toxicity in mice. To summarize, our data demonstrated potent anti-RVFV activity of benzavir-2 in vitro together with a promising pre-clinical pharmacokinetic profile. This data support further exploration of the antiviral activity of benzavir-2 in in vivo efficacy models that may lead to further drug development for human use.
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7. |
- Krzyzanowski, Adrian, et al.
(author)
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Synthesis of Indole-, Benzo[ b]thiophene-, and Benzo[ b]selenophene-Based Analogues of the Resveratrol Dimers Viniferifuran and (±)-Dehydroampelopsin B.
- 2018
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In: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 20:21, s. 6650-6654
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Journal article (peer-reviewed)abstract
- A convenient synthetic strategy to obtain viniferifuran and (±)-dehydroampelopsin B analogues based on the heterocyclic cores of indole, benzo[ b]thiophene, and benzo[ b]selenophene is presented. The key transformations utilized in the described syntheses include Sonogashira couplings, Cacchi and alkyne electrophilic cyclizations, Horner-Wadsworth-Emmons (HWE) reaction, chemoselective Suzuki-Miyaura couplings, and acid-promoted intramolecular cyclization to form the seven-membered ring of (±)-dehydroampelopsin B.
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8. |
- Kumar, Arvind, et al.
(author)
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Cyclopropylmethyl Protection of Phenols : Total Synthesis of the Resveratrol Dimers Anigopreissin A and Resveratrol-Piceatannol Hybrid
- 2018
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In: ChemistryOpen. - : Wiley-VCH Verlagsgesellschaft. - 2191-1363. ; 7:12, s. 953-956
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Journal article (peer-reviewed)abstract
- We demonstrate the versatile use of the cyclopropylmethyl group to protect phenols through the total synthesis of two benzofuran-based natural products, that is, anigopreissin A and the resveratrol-piceatannol hybrid. This protecting group is a good alternative to the conventional methyl group, owing to the feasibility of introduction, stability under a variety of conditions, and its relative ease of removal under different acidic conditions.
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9. |
- Lindgren, Anders E. G., et al.
(author)
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PARP Inhibitor with Selectivity Toward ADP-Ribosyltransferase ARTD3/PARP3
- 2013
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In: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 8:8, s. 1698-1703
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Journal article (peer-reviewed)abstract
- Inhibiting ADP-ribosyl transferases with PARP-inhibitors is considered a promising strategy for the treatment of many cancers and ischemia, but most of the cellular targets are poorly characterized. Here, we describe an inhibitor of ADP-ribosyltransferase-3/poly(ADP-ribose) polymerase-3 (ARTD3), a regulator of DNA repair and mitotic progression. In vitro profiling against 12, members of the enzyme family suggests selectivity for ARTD3, and crystal structures illustrate the molecular basis for inhibitor selectivity. The compound is active in cells, where it elicits ARTD3-specific effects at submicromolar concentration. Our results show that by targeting the nicotinamide binding site, selective inhibition can be achieved among the closest relatives of the validated clinical target, ADP-ribosyltransferase-1/poly(ADP-ribose) polymerase-1.
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10. |
- Lindgren, Anders E G, et al.
(author)
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Statistical molecular design : a tool to follow up hits from small-molecule screening.
- 2014
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In: Methods in Molecular Biology. - Totowa, NJ : Springer. - 1064-3745 .- 1940-6029. ; 1056, s. 169-188
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Journal article (peer-reviewed)abstract
- In high-throughput screening (HTS) a robust assay is used to interrogate a large collection of small organic molecules in order to find compounds, hits, with a desired biological activity. The hits are then further explored by an iterative process where new compounds are designed, purchased, or synthesized, followed by an evaluation in one or more assays. Statistical molecular design (SMD) is a useful method to select a balanced, varied, and information-rich compound collection based on hits from HTS in order to create a foundation for development of optimized compounds with improved properties. In this chapter, we describe the use of SMD to explore a hit obtained from small-molecule screening.
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