Publications by authors named "Peter Bellstedt"

Detection and discrimination of similar solvation energies of bioanalytes are vital in medical and practical applications. Currently, various advanced techniques are equipped to recognize these crucial bioanalytes. Each strategy has its own benefits and limitations.

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Background: Teucrium hyrcanicum L. (family Lamiaceae) is widely distributed in the North and Northwest of Iran. It has been used in the form of tea, tonic, and tincture for the treatment of various diseases such as cough, rheumatism, and fever.

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  • * The study found that bile affects the movement of drugs through mucus, leading to changes in how quickly certain drugs can diffuse when bile is present, while some drugs remain unaffected.
  • * By examining over 50 drugs, researchers discovered that those interacting with bile also interacted with mucus, indicating a strong connection between bile interaction and drug transport in the body.
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  • - Sphingolipids are important lipids for cell function and nerve health; issues with their metabolism are linked to nervous system disorders.
  • - The enzyme DEGS1 is crucial for producing ceramide from dihydroceramide, and mutations in this enzyme can lead to serious conditions like leukodystrophy.
  • - Two new variants of the DEGS1 gene were studied, revealing that one variant (p.R311K) appears harmful while another (p.G270E) is likely benign, highlighting the potential importance of SPB 18:1(14Z);O2 as a specific biomarker for understanding these mutations.
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Diatoms are abundant unicellular microalgae, responsible for ≈20 % of global photosynthetic CO fixation. Nevertheless, we know little about fundamental aspects of their biology, such as their sexual reproduction. Pheromone-mediated chemical communication is crucial for successful mating.

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  • The study investigates the human organic cation transporter 2 (OCT2), which transports certain drugs and amines across cell membranes, focusing on its unique and complex binding sites.
  • Using thermal shift assays and molecular modeling, researchers identified two distinct binding sites for ligands on OCT2, assessing their effects through inhibition assays and radiolabeled uptake experiments.
  • Findings revealed that some compounds, like gentamicin and methotrexate, stabilize OCT2 without inhibiting its function, while others, like amiloride, inhibit uptake but don't impact thermal stability, indicating varied interactions and thermodynamic properties among ligands.
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  • * NMR spectroscopy is highlighted as a better technique for studying IDPs, providing detailed insights into their structure and dynamics through advanced experimental approaches.
  • * The study shows that N-C band-selective heteronuclear cross-polarization can effectively transfer carbon magnetization from one amino acid to its neighbors, allowing researchers to obtain correlation spectra that reveal interactions within IDPs.
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Reactive polymersomes represent a versatile artificial cargo carrier system that can facilitate an immediate release in response to a specific stimulus. The herein presented oxidation-sensitive polymersomes feature a time-delayed release mechanism in an oxidative environment, which can be precisely adjusted by either tuning the membrane thickness or partial pre-oxidation. These polymeric vesicles are conveniently prepared by PISA allowing the straightforward and effective in situ encapsulation of cargo molecules, as shown for dyes and enzymes.

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The first total synthesis of the actin-stabilizing marine natural product geodiamolide H was achieved. Solid-phase based peptide assembly paired with scalable stereoselective syntheses of polyketide building blocks and an optimized esterification set the stage for investigating the key ring-closing metathesis. Geodiamolide H and synthetic analogues were characterized for their toxicity and for antiproliferative effects in cellulo, by characterising actin polymerization induction in vitro, and by docking on the F-actin target and property computation in silico, for a better understanding of structure-activity relationships (SAR).

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Phosphate glass dissolution can be tailored via compositional and subsequent structural changes, which is of interest for biomedical applications such as therapeutic ion delivery. Here, solid-state P nuclear magnetic resonance characterisation of 45PO-xCaO - (55 -x)NaO glasses was correlated with dissolution studies using time-dependent liquid P NMR spectroscopy and quantitative chemical analysis. Glasses dissolved congruently in aqueous media, and the first dissolution stage was the hydration of phosphate chains.

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An anion sensor is presented that combines a bidentate hydrogen- (HB) or halogen-bonding (XB) site with a luminescent monocationic Ir fragment for strong binding of common anions (K up to 6×10  m ) with diagnostic emission changes. A new emission-based protocol for fast and reliable detection was derived on the basis of correction for systematic but unspecific background effects. Such a simple correction routine circumvents the hitherto practical limitations of systematic emission-based analysis of anion binding with validated open-source software (BindFit).

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We describe the synthesis of hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (PmPEGMA) and hydrophobic poly(methyl methacrylate) (PMMA) caspofungin conjugates by a post-polymerization modification of copolymers containing 10 mol % pentafluorophenyl methacrylate (PFPMA), which were obtained via reversible addition-fragmentation chain transfer copolymerization. The coupling of the clinically used antifungal caspofungin was confirmed and quantified in detail by a combination of H-, F- and diffusion-ordered NMR spectroscopy, UV-vis spectroscopy, and size exclusion chromatography. The trifunctional amine-containing antifungal was attached via several amide bonds to the hydrophobic PMMA, but sterical hindrance induced by the mPEGMA side chains prohibited intramolecular double functionalization.

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The hydrophosphorylation of phenylacetylene with di(aryl)phosphane oxides Ar P(O)H (Pudovik reaction) yields E/Z-isomer mixtures of phenylethenyl-di(aryl)phosphane oxides (1). Alkali and alkaline-earth metal di(aryl)phosphinites have been studied as catalysts for this reaction with increasing activity for the heavier s-block metals. The Pudovik reaction can only be mediated for di(aryl)phosphane oxides whereas P-bound alkyl and alcoholate substituents impede the P-H addition across alkynes.

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  • Cytokines from the interleukin (IL)-1 family play key roles in controlling immune and inflammatory responses, with the recently identified IL-36 family involved in conditions like psoriasis and arthritis.
  • The study reveals that IL-36α interacts with heme, highlighting two specific heme-binding sites and providing structural insights through spectroscopy and NMR analysis.
  • Findings suggest that heme negatively regulates IL-36 signaling in rheumatoid arthritis fibroblast cells, indicating that IL-1 cytokines may be influenced by heme, expanding our understanding of heme-binding proteins.
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The N-terminal segment of human cystathionine-β-synthase (CBS(1-40)) constitutes an intrinsically disordered protein stretch that transiently interacts with heme. We illustrate that the HCBCACON experimental protocol provides an efficient alternative approach for probing transient interactions of intrinsically disordered proteins with heme in situations where the applicability of the conventional [H, N]-HSQC experiment may be limited. This experiment starting with the excitation of protein side chain protons delivers information about the proline residues and thereby makes it possible to use these residues in interaction mapping experiments.

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Interleukins are cytokines performing central tasks in the human immune system. Interleukin-36β (IL-36β) is a member of the interleukin-1 superfamily as are its homologues IL-36α and IL-36γ. All of them interact with a common receptor composed of IL-36R and IL-1R/acP.

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Maturity stage affects the bioactive compounds as well as the antioxidant capacity in the fruit. This study was designed to identify and quantify carotenoids, as well as to evaluate vitamin E, vitamin C, antioxidant capacity and total phenolic compounds of hips at different degrees of ripeness. HPLC (high performance liquid chromatography) analysis showed different types of carotenoids at different stages of maturity of hips with significant differences ( Ë‚ 0.

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Photochemically induced dynamic nuclear polarization (photo-CIDNP) has been observed in the homodimeric, type-1 photochemical reaction centers (RCs) of the acidobacterium, Chloracidobacterium (Cab.) thermophilum, by N magic-angle spinning (MAS) solid-state NMR under continuous white-light illumination. Three light-induced emissive (negative) signals are detected.

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Cystathionine-β-synthase (CBS) belongs to a large family of pyridoxal 5'-phosphate (PLP)-dependent enzymes, responsible for the sulfur metabolism. The heme-dependent protein CBS is part of regulatory pathways also involving the gasotransmitter hydrogen sulfide. Malfunction of CBS can lead to pathologic conditions like cancer, cardiovascular and neurodegenerative disorders.

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  • The study focuses on identifying diols, which is important for medical diagnostics like measuring glucose in diabetic patients.
  • It introduces a new method using fluorinated boronic acid-appended pyridinium salts combined with F NMR spectroscopy, overcoming the limitations of traditional diol sensors.
  • The new receptors show high sensitivity and selectivity in detecting various substances, including distinguishing glucose and fructose in mixtures and identify glucose in urine samples down to 1 mM.
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Twenty amino acid substitutions in the thymidine kinase (TK) of clinical herpes simplex virus type 1 strains were assessed for conferring acyclovir (ACV) resistance. Site-directed mutagenesis, cell-free protein synthesis and protein expression in Escherichia coli were performed to obtain recombinant TK proteins, which were authenticated by Western blotting. A modified enzyme-linked immunosorbent assay (ELISA) was carried out to determine the phosphorylation activity of the mutants towards 5-bromo-2'-deoxyuridine (BrdU).

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A crown-ether containing the iodo-triazole moiety for simultaneous cation-anion binding through Lewis-basic nitrogen atoms and C-II halogen-bond-donating iodine atoms was prepared. The complexation of the heteroditopic receptor was illustrated by X-ray and DFT analysis. The cooperative effect boosting the anion affinity was quantified by H/C NMR titration experiments.

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Biomimetic hydrogels are advanced biomaterials that have been developed following different synthetic routes. Covalent postfabrication functionalization is a promising strategy to achieve efficient matrix modification decoupled of general material properties. To this end, dual-functional macromers were synthesized by free radical polymerization of maleic anhydride with diacetone acrylamide (N-(1,1-dimethyl-3-oxobutyl)acrylamide) and pentaerythritol diacrylate monostearate.

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  • Four products from the breakdown of bilirubin were isolated and characterized, identified as constitutional isomers of propentdyopents (PDPs).
  • These PDPs can further transform into biologically active compounds known as bilirubin oxidation end products (Z-BOXes).
  • The presence of PDPs was confirmed in human bile and gallstones, suggesting they might play a role in conditions like cerebral vasospasms and liver dysfunction.
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The RF pulse scheme RN[N-CA HEHAHA]NH, which provides a convenient approach to the acquisition of different multidimensional chemical shift correlation NMR spectra leading to backbone resonance assignments, including those of the proline residues of intrinsically disordered proteins (IDPs), is experimentally demonstrated. Depending on the type of correlation data required, the method involves the generation of in-phase ((15) N)(x) magnetisation via different magnetisation transfer pathways such as H→N→CO→N, HA→CA→CO→N, H→N→CA→N and H→CA→N, the subsequent application of (15) N-(13) C(α) heteronuclear Hartmann-Hahn mixing over a period of ≈100 ms, chemical-shift labelling of relevant nuclei before and after the heteronuclear mixing step and amide proton detection in the acquisition dimension. It makes use of the favourable relaxation properties of IDPs and the presence of (1) JCαN and (2) JCαN couplings to achieve efficient correlation of the backbone resonances of each amino acid residue "i" with the backbone amide resonances of residues "i-1" and "i+1".

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Synopsis of recent research by authors named "Peter Bellstedt"

  • - Peter Bellstedt's recent research encompasses a diverse range of topics, with a significant focus on the molecular mechanisms of biological processes, including the interaction of bile with mucosal mechanics and the investigation of sphingolipids related to neurological disorders.
  • - His work also emphasizes the development of innovative detection strategies, such as utilizing F NMR probes for selective anion detection and exploring techniques to enhance the stability and transport functions of human organic cation transporters.
  • - Additionally, Bellstedt is engaged in bioactive compound research, analyzing the cytotoxicity and antioxidant activities of plants, and contributing to the understanding of molecular structures crucial to various biomedical applications.