| 1. |
- Abujubara, Helal, et al.
(författare)
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Substrate-derived Sortase A inhibitors: targeting an essential virulence factor of Gram-positive pathogenic bacteria
- 2023
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Ingår i: Chemical Science. - 2041-6520 .- 2041-6539. ; 14:25, s. 6975-6985
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Tidskriftsartikel (refereegranskat)abstract
- The bacterial transpeptidase Sortase A (SrtA) is a surface enzyme of Gram-positive pathogenic bacteria. It has been shown to be an essential virulence factor for the establishment of various bacterial infections, including septic arthritis. However, the development of potent Sortase A inhibitors remains an unmet challenge. Sortase A relies on a five amino acid sorting signal (LPXTG), by which it recognizes its natural target. We report the synthesis of a series of peptidomimetic inhibitors of Sortase A based on the sorting signal, supported by computational binding analysis. By employing a FRET-compatible substrate, our inhibitors were assayed in vitro. Among our panel, we identified several promising inhibitors with IC50 values below 200 mu M, with our strongest inhibitor - LPRDSar - having an IC50 of 18.9 mu M. Furthermore, it was discovered that three of our compounds show an effect on growth and biofilm inhibition of pathogenic Staphylococcus aureus, with the inclusion of a phenyl ring seemingly key to this effect. The most promising compound in our panel, BzLPRDSar, could inhibit biofilm formation at concentrations as low as 32 mu g mL(-1), manifesting it as a potential future drug lead. This could lead to treatments for MRSA infections in clinics and diseases such as septic arthritis, which has been directly linked with SrtA.
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| 2. |
- Baumruck, A. C., et al.
(författare)
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Native Chemical Ligation of Highly Hydrophobic Peptides in Ionic Liquid-Containing Media
- 2021
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 86:2, s. 1659-1666
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Tidskriftsartikel (refereegranskat)abstract
- The chemical synthesis of a highly hydrophobic membrane-associated peptide by native chemical ligation (NCL) in an ionic liquid (IL) [C2mim][OAc]/buffer mixture was achieved by employing peptide concentrations up to 11 mM. NCL was studied at different pH and water content and compared to several "gold-standard"ligation protocols. The optimized reaction protocol for the NCL in IL required the addition of 40% water and pH adjustment to 7.0-7.5, resulting in ligation yields of up to 80-95% within 1 to 4 h. This new ligation protocol is generally applicable and outperforms current "gold-standard"NCL methods. ©
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| 3. |
- Beyer, Luisa I., et al.
(författare)
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Mimicking Nonribosomal Peptides from the Marine Actinomycete Streptomyces sp. H-KF8 Leads to Antimicrobial Peptides
- 2023
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Ingår i: ACS Infectious Diseases. - 2373-8227. ; 10:1, s. 79-92
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Tidskriftsartikel (refereegranskat)abstract
- Microorganisms within the marine environment have been shown to be very effective sources of naturally produced antimicrobial peptides (AMPs). Several nonribosomal peptides were identified based on genome mining predictions of Streptomyces sp. H-KF8, a marine Actinomycetota isolated from a remote Northern Chilean Patagonian fjord. Based on these predictions, a series of eight peptides, including cyclic peptides, were designed and chemically synthesized. Six of these peptides showed antimicrobial activity. Mode of action studies suggest that two of these peptides potentially act on the cell membrane via a novel mechanism allowing the passage of small ions, resulting in the dissipation of the membrane potential. This study shows that though structurally similar peptides, determined by NMR spectroscopy, the incorporation of small sequence mutations results in a dramatic influence on their bioactivity including mode of action. The qualified hit sequence can serve as a basis for more potent AMPs in future studies.
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| 4. |
- Bharmoria, Pankaj, 1985, et al.
(författare)
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Protein cohabitation: long-term immunoglobulin G storage at room temperature
- 2023
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Ingår i: Journal of Materials Chemistry B. - : Royal Society of Chemistry. - 2050-750X .- 2050-7518. ; 11:24, s. 5400-5405
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Tidskriftsartikel (refereegranskat)abstract
- Long-term functional storage of therapeutic proteins at room temperature has been an eternal challenge. Inspired by the cellular cooperativity of proteins, we have taken a step forward to address this challenge by cohabitating Immunoglobulin G (IgG1) with a food protein gelatin in the solid-state at room temperature. Interestingly, IgG1 remained functionally active for a record 14 months revealed from the western-blot assay. Further quantification by HP-LC analysis showed 100% structural integrity of IgG1 with no degradation in the gelatin matrix during this period. The developed formulation has a direct application in oral medical nutrition therapy to cure gastrointestinal microbial infections. Also the strategy provides a robust energy economic alternative to the protein engineering methods for long-term functional storage of therapeutic proteins at room temperature.
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| 5. |
- Hintzen, Jordi, 1994, et al.
(författare)
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Fluorescence Labeling of Peptides: Finding the Optimal Protocol for Coupling Various Dyes to ATCUN-like Structures
- 2024
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Ingår i: ACS ORGANIC & INORGANIC AU. - 2694-247X.
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Tidskriftsartikel (refereegranskat)abstract
- Labeling of peptides and proteins with fluorescent dyes is a key step in functionalizing these structures for a wide array of biological assays. However, coupling strategies of such dyes have not been optimized for the most common compounds, while this step is typically the most precious and costly of the whole synthesis. We searched for the best conditions for attachment of the most widely used fluorescent dyes such as 6-carboxyfluorescein, Rhodamine B, and BODIPY-FL to peptides, where amino terminal Cu(II) and Ni(II) binding site (ATCUN) peptides were used as a model system. Surprisingly, conventional methods of dye attachment proved to not be satisfactory and yielded poor efficiency results. We have discovered that when labeling primary amines on peptides, the uncommon synthesis of activated pentafluorophenol (PFP) esters is the most efficient strategy, expedited by microwave irradiation. Coupling to secondary amines is achieved most efficiently through conventional coupling reagents such as HATU and PyBOP. Furthermore, we have employed our fluorescently labeled ATCUN peptides in studies for Cu(II) and Ni(II) sensing, showing that changing the fluorophore does not significantly affect the fluorescence quenching process and discovering the optimal linker length between the ATCUN core and the dye, expanding the repertoire of fluorophores that can be used in this application.
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| 6. |
- Montoliu-Gaya, Laia, et al.
(författare)
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CA10 regulates neurexin heparan sulfate addition via a direct binding in the secretory pathway
- 2021
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Ingår i: Embo Reports. - : EMBO. - 1469-221X .- 1469-3178. ; 22:4
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Tidskriftsartikel (refereegranskat)abstract
- Neurexins are presynaptic adhesion molecules that shape the molecular composition of synapses. Diversification of neurexins in numerous isoforms is believed to confer synapse-specific properties by engaging with distinct ligands. For example, a subset of neurexin molecules carry a heparan sulfate (HS) glycosaminoglycan that controls ligand binding, but how this post-translational modification is controlled is not known. Here, we observe that CA10, a ligand to neurexin in the secretory pathway, regulates neurexin-HS formation. CA10 is exclusively found on non-HS neurexin and CA10 expressed in neurons is sufficient to suppress HS addition and attenuate ligand binding and synapse formation induced by ligands known to recruit HS. This effect is mediated by a direct interaction in the secretory pathway that blocks the primary step of HS biosynthesis: xylosylation of the serine residue. NMR reveals that CA10 engages residues on either side of the serine that can be HS-modified, suggesting that CA10 sterically blocks xylosyltransferase access in Golgi. These results suggest a mechanism for the regulation of HS on neurexins and exemplify a new mechanism to regulate site-specific glycosylations.
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| 7. |
- Muller, L. K., et al.
(författare)
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Ultrasensitive and Selective Copper(II) Detection: Introducing a Bioinspired and Robust Sensor
- 2020
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Ingår i: Chemistry-a European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 26:39, s. 8511-8517
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Tidskriftsartikel (refereegranskat)abstract
- A nanopore-based Cu-II-sensing system is reported that allows for an ultrasensitive and selective detection of Cu(II)with the possibility for a broad range of applications, for example in medical diagnostics. A fluorescent ATCUN-like peptide 5/6-FAM-Dap-beta-Ala-His is employed to selectively bind Cu(II)ions in the presence of Ni(II)and Zn(II)and was crafted into ion track-etched nanopores. Upon Cu(II)binding the fluorescence of the peptide sensor is quenched, permitting the detection of Cu(II)in solution. The ion transport characteristics of peptide-modified nanopore are shown to be extremely sensitive and selective towards Cu(II)allowing to sense femtomolar Cu(II)concentrations in human urine mimics. Washing with EDTA fully restores the Cu-II-binding properties of the sensor, enabling multiple repetitive measurements. The robustness of the system clearly has the potential to be further developed into an easy-to-use, lab-on-chip Cu-II-sensing device, which will be of great importance for bedside diagnosis and monitor of Cu(II)levels in patients with copper-dysfunctional homeostasis.
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| 8. |
- Tietze, Daniel, 1980, et al.
(författare)
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Structural and Dynamical Basis of G Protein Inhibition by YM-254890 and FR900359: An Inhibitor in Action
- 2019
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Ingår i: Journal of Chemical Information and Modeling. - : American Chemical Society (ACS). - 1549-9596 .- 1549-960X. ; 59:10, s. 4361-4373
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Tidskriftsartikel (refereegranskat)abstract
- Specific inhibition of G proteins holds a great pharmacological promise to, e.g., target oncogenic G(q/11) proteins and can be achieved by the two natural products FR900359 (FR) and YM-254890 (YM). Unfortunately, recent rational-design-based approaches to address G proteins other than G(q/11/14) subtypes were not successful mainly due to the conformational complexity of these new modalities-like compounds. Here, we report the water-derived NMR structure of YM, which strongly differs from the conformation of G(q)-bound YM as found in the crystal structure. Reanalysis of the crystal structure suggests that the water-derived NMR structure of YM also represents a valid solution of the electron density. Extensive molecular dynamic simulations unveiled much higher binding affinities of the water-derived NMR structure compared to the original YM conformation of pdb 3ah8. Employing a in-silico-designed, fast activating G protein conformation molecular dynamics data ultimately show how the inhibitor impairs the domain motion of the G protein necessary to hinder nucleotide exchange.
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| 9. |
- Wehrli, Patrick M., et al.
(författare)
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Discovery and development of substituted thiadiazoles as inhibitors of Staphylococcus aureus Sortase A
- 2019
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896. ; 27:19
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Tidskriftsartikel (refereegranskat)abstract
- High-throughput screening of small-molecule libraries has led to the identification of thiadiazoles as a new class of inhibitors against Staphylococcus aureus sortase A (SrtA). N-(5-((4-nitrobenzyl) thio)-1,3,4-thiadiazol-2-yl)nicotinamide (IC50= 3.8 mu M) was identified as a potent inhibitor of SrtA after synthetic modification of hit compounds. Additional ligands developed in this study displayed affinities in the low micromolar range without affecting bacterial growth in vitro. The study also suggest a new mode of action through covalent binding to the active site cysteine.
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