Recent research has highlighted the pivotal role of lipoxygenases in modulating ferroptosis and immune responses by catalyzing the generation of lipid peroxides. However, the limitations associated with protein enzymes, such as poor stability, low bioavailability, and high production costs, have motivated researchers to explore biomimetic materials with lipoxygenase-like activity. Here, we report the discovery of lipoxygenase-like two-dimensional (2D) MoS2nanosheets capable of catalyzing lipid peroxidation and inducing ferroptosis. The resulting catalytic products were successfully identified using mass spectrometry and a luminescent substrate. Unlike native lipoxygenases, MoS2 nanosheets exhibited exceptional catalytic activity at extreme pH, high temperature, high ionic strength, and organic solvent conditions. Structure-activity relationship analysis indicates that sulfur atomic vacancy sites on MoS2 nanosheets are responsible for their catalytic activity. Furthermore, the lipoxygenase-like activity of MoS2 nanosheets was demonstrated within mammalian cells and animal tissues, inducing distinctive ferroptotic cell death. In summary, this research introduces an alternative to lipoxygenase to regulate lipid peroxidation in cells, offering a promising avenue for ferroptosis induction.
- MeSH
- biomimetické materiály chemie farmakologie metabolismus MeSH
- disulfidy * chemie metabolismus MeSH
- ferroptóza * účinky léků MeSH
- katalýza MeSH
- lidé MeSH
- lipoxygenasa * metabolismus chemie MeSH
- molybden chemie metabolismus MeSH
- myši MeSH
- nanostruktury chemie MeSH
- peroxidace lipidů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Insulin is a peptide responsible for regulating the metabolic homeostasis of the organism; it elicits its effects through binding to the transmembrane insulin receptor (IR). Insulin mimetics with agonistic or antagonistic effects toward the receptor are an exciting field of research and could find applications in treating diabetes or malignant diseases. We prepared five variants of a previously reported 20-amino acid insulin-mimicking peptide. These peptides differ from each other by the structure of the covalent bridge connecting positions 11 and 18. In addition to the peptide with a disulfide bridge, a derivative with a dicarba bridge and three derivatives with a 1,2,3-triazole differing from each other by the presence of sulfur or oxygen in their staples were prepared. The strongest binding to IR was exhibited by the peptide with a disulfide bridge. All other derivatives only weakly bound to IR, and a relationship between increasing bridge length and lower binding affinity can be inferred. Despite their nanomolar affinities, none of the prepared peptide mimetics was able to activate the insulin receptor even at high concentrations, but all mimetics were able to inhibit insulin-induced receptor activation. However, the receptor remained approximately 30% active even at the highest concentration of the agents; thus, the agents behave as partial antagonists. An interesting observation is that these mimetic peptides do not antagonize insulin action in proportion to their binding affinities. The compounds characterized in this study show that it is possible to modulate the functional properties of insulin receptor peptide ligands using disulfide mimetics.
- MeSH
- disulfidy chemie MeSH
- inzulin * metabolismus MeSH
- peptidy chemie MeSH
- receptor inzulinu * MeSH
- Publikační typ
- časopisecké články MeSH
Garlic is a well-known example of natural self-defence system consisting of an inactive substrate (alliin) and enzyme (alliinase) which, when combined, produce highly antimicrobial allicin. Increase of alliinase stability and its activity are of paramount importance in various applications relying on its use for in-situ synthesis of allicin or its analogues, e.g., pulmonary drug delivery, treatment of superficial injuries, or urease inhibitors in fertilizers. Here, we discuss the effect of temperature, pH, buffers, salts, and additives, i.e. antioxidants, chelating agents, reducing agents and cosolvents, on the stability and the activity of alliinase extracted from garlic. The effects of the storage temperature and relative humidity on the stability of lyophilized alliinase was demonstrated. A combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin's mode of action and develop effective defence mechanism, which could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant (MDR) bacterial strains.
- MeSH
- antibakteriální látky farmakologie MeSH
- Bacteria účinky léků ultrastruktura MeSH
- biokatalýza účinky léků MeSH
- časové faktory MeSH
- česnek enzymologie MeSH
- chemické jevy * MeSH
- disulfidy chemie metabolismus MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny sulfinové chemie metabolismus MeSH
- lyasy štěpící vazby C-S metabolismus MeSH
- lyofilizace MeSH
- mikrobiální testy citlivosti MeSH
- mikrobiální viabilita účinky léků MeSH
- pufry MeSH
- stabilita enzymů účinky léků MeSH
- stereoizomerie MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aggregation of the neuronal protein α-synuclein into amyloid fibrils plays a central role in the development of Parkinson's disease. Growth of fibrils can be suppressed by blocking fibril ends from their interaction with monomeric proteins. In this work, we constructed inhibitors that bind to the ends of α-synuclein amyloid fibrils with very high affinity. They are based on synthetic α-synuclein dimers and interact with fibrils via two monomeric subunits adopting conformation that efficiently blocks fibril elongation. By tuning the charge of dimers, we further enhanced the binding affinity and prepared a construct that inhibits fibril elongation at nanomolar concentration (IC50 ≈ 20 nM). To the best of our knowledge, it is the most efficient inhibitor of α-synuclein fibrillization.
- MeSH
- alfa-synuklein antagonisté a inhibitory genetika metabolismus MeSH
- amyloid antagonisté a inhibitory chemie metabolismus MeSH
- cirkulární dichroismus MeSH
- disulfidy chemie MeSH
- látky ovlivňující centrální nervový systém chemie farmakologie MeSH
- lidé MeSH
- multimerizace proteinu MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
From the rediscovery of graphene in 2004, the interest in layered graphene analogs has been exponentially growing through various fields of science. Due to their unique properties, novel two-dimensional family of materials and especially transition metal dichalcogenides are promising for development of advanced materials of unprecedented functions. Progress in 2D materials synthesis paved the way for the studies on their hybridization with other materials to create functional composites, whose electronic, physical or chemical properties can be engineered for special applications. In this review we focused on recent progress in graphene-based and MoS2 hybrid nanostructures. We summarized and discussed various fabrication approaches and mentioned different 2D and 3D structures of composite materials with emphasis on their advances for electroanalytical chemistry. The major part of this review provides a comprehensive overview of the application of graphene-based materials and MoS2 composites in the fields of electrochemical sensors and biosensors.
Human insulin-like growth factor 1 (IGF-1) is a 70 amino acid protein hormone, with key impact on growth, development, and lifespan. The physiological and clinical importance of IGF-1 prompted challenging chemical and biological trials toward the development of its analogs as molecular tools for the IGF-1 receptor (IGF1-R) studies and as new therapeutics. Here, we report a new method for the total chemical synthesis of IGF-1 analogs, which entails the solid-phase synthesis of two IGF-1 precursor chains that is followed by the CuI-catalyzed azide-alkyne cycloaddition ligation and by biomimetic formation of a native pattern of disulfides. The connection of the two IGF-1 precursor chains by the triazole-containing moieties, and variation of its neighboring sequences (Arg36 and Arg37), was tolerated in IGF-1R binding and its activation. These new synthetic IGF-1 analogs are unique examples of disulfide bonds' rich proteins with intra main-chain triazole links. The methodology reported here also presents a convenient synthetic platform for the design and production of new analogs of this important human hormone with non-standard protein modifications.
- MeSH
- arginin chemie MeSH
- buňky NIH 3T3 účinky léků MeSH
- cykloadiční reakce MeSH
- disulfidy chemie MeSH
- fibroblasty MeSH
- fosforylace MeSH
- insulinu podobný růstový faktor I analogy a deriváty chemická syntéza chemie metabolismus farmakologie MeSH
- lidé MeSH
- měď chemie MeSH
- methionin chemie MeSH
- myši MeSH
- preklinické hodnocení léčiv metody MeSH
- proteinové domény MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- receptor IGF typ 1 metabolismus MeSH
- syntetická chemie okamžité shody MeSH
- techniky syntézy na pevné fázi MeSH
- triazoly chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hydrophobins are small proteins that play a role in a number of processes during the filamentous fungi growth and development. These proteins are characterized by the self-assembly of their molecules into an amphipathic membrane at hydrophilic-hydrophobic interfaces. Isolation and purification of hydrophobins generally present a challenge in their analysis. Hydrophobin SC3 from Schizophyllum commune was selected as a representative of class I hydrophobins in this work. A novel procedure for selective and effective isolation of hydrophobin SC3 based on solid-phase extraction with polytetrafluoroethylene microparticles loaded in a small self-made microcolumn is reported. The tailored binding of hydrophobins to polytetrafluoroethylene followed by harsh elution conditions resulted in a highly specific isolation of hydrophobin SC3 from the model mixture of ten proteins. The presented isolation protocol can have a positive impact on the analysis and utilization of these proteins including all class I hydrophobins. Hydrophobin SC3 was further subjected to reduction of its highly stable disulfide bonds and to chymotryptic digestion followed by mass spectrometric analysis. The isolation and digestion protocols presented in this work make the analysis of these highly hydrophobic and compact proteins possible.
- MeSH
- albuminy chemie MeSH
- ananasovník chemie MeSH
- bromelainy chemie MeSH
- Canavalia chemie MeSH
- chymotrypsin chemie MeSH
- cytochromy c chemie MeSH
- disulfidy chemie MeSH
- erytrocyty enzymologie MeSH
- extrakce na pevné fázi metody MeSH
- hmotnostní spektrometrie metody MeSH
- karboanhydrasy chemie MeSH
- kaseiny chemie MeSH
- koně MeSH
- konkanavalin A chemie MeSH
- kur domácí MeSH
- lidé MeSH
- mikrosféry * MeSH
- mléko enzymologie MeSH
- myokard metabolismus MeSH
- polytetrafluoroethylen chemie MeSH
- proteomika metody MeSH
- Schizophyllum chemie MeSH
- skot MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- tandemová hmotnostní spektrometrie MeSH
- thermolysin chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Interferon-γ receptor 2 is a cell-surface receptor that is required for interferon-γ signalling and therefore plays a critical immunoregulatory role in innate and adaptive immunity against viral and also bacterial and protozoal infections. A crystal structure of the extracellular part of human interferon-γ receptor 2 (IFNγR2) was solved by molecular replacement at 1.8 Å resolution. Similar to other class 2 receptors, IFNγR2 has two fibronectin type III domains. The characteristic structural features of IFNγR2 are concentrated in its N-terminal domain: an extensive π-cation motif of stacked residues KWRWRH, a NAG-W-NAG sandwich (where NAG stands for N-acetyl-D-glucosamine) and finally a helix formed by residues 78-85, which is unique among class 2 receptors. Mass spectrometry and mutational analyses showed the importance of N-linked glycosylation to the stability of the protein and confirmed the presence of two disulfide bonds. Structure-based bioinformatic analysis revealed independent evolutionary behaviour of both receptor domains and, together with multiple sequence alignment, identified putative binding sites for interferon-γ and receptor 1, the ligands of IFNγR2.
- MeSH
- aminokyselinové motivy MeSH
- disulfidy chemie MeSH
- glykosylace MeSH
- konformace proteinů MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- molekulární modely MeSH
- proteinové domény MeSH
- receptory interferonů chemie MeSH
- sbalování proteinů MeSH
- stabilita proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Anterior Gradient-2 (AGR2) is a component of a pro-oncogenic signalling pathway that can promote p53 inhibition, metastatic cell migration, limb regeneration, and cancer drug-resistance. AGR2 is in the protein-disulphide isomerase superfamily containing a single cysteine (Cys-81) that forms covalent adducts with its client proteins. We have found that mutation of Cysteine-81 attenuates its biochemical activity in its sequence-specific peptide docking function, reduces binding to Reptin, and reduces its stability in cells. As such, we evaluated how chemical oxidation of its cysteine affects its biochemical properties. Recombinant AGR2 spontaneously forms covalent dimers in the absence of reductant whilst DTT promotes dimer to monomer conversion. Mutation of Cysteine-81 to alanine prevents peroxide catalysed dimerization of AGR2 in vitro, suggesting a reactive cysteine is central to covalent dimer formation. Both biochemical assays and ESI mass spectrometry were used to demonstrate that low levels of a chemical oxidant promote an intermolecular disulphide bond through formation of a labile sulfenic acid intermediate. However, higher levels of oxidant promote sulfinic or sulfonic acid formation thus preventing covalent dimerization of AGR2. These data together identify the single cysteine of AGR2 as an oxidant responsive moiety that regulates its propensity for oxidation and its monomeric-dimeric state. This has implications for redox regulation of the pro-oncogenic functions of AGR2 protein in cancer cells.
- MeSH
- chemorezistence genetika MeSH
- cystein genetika metabolismus MeSH
- disulfidy chemie metabolismus MeSH
- DNA-helikasy chemie genetika metabolismus MeSH
- hmotnostní spektrometrie MeSH
- kyseliny sulfenové metabolismus MeSH
- lidé MeSH
- MFC-7 buňky MeSH
- multimerizace proteinu genetika MeSH
- mutace MeSH
- nádory chemie genetika patologie MeSH
- oxidace-redukce * MeSH
- proteiny chemie genetika metabolismus MeSH
- sekvence aminokyselin genetika MeSH
- signální transdukce MeSH
- transportní proteiny chemie genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Per(2,3,6-tri-O-benzyl)-γ-cyclodextrin was debenzylated by DIBAL-H to produce a mixture of C6(I),C6(IV) and C6(I),C6(V) isomeric diols, which were separated and isolated. The C2-symmetrical C6(I),C6(V) diol was transformed into dithiol and dimerized to produce a γ-cyclodextrin duplex structure. A crystal structure revealed tubular cavity whose peripheries are slightly elliptically distorted. The solvent accessible volume of the cavity of the γ-CD duplex is about 740 Å(3). Due to this large inner space the duplex forms very stable inclusion complexes with steroids; bile acids examined in this study show binding affinities to the γ-cyclodextrin duplex in the range of 5.3 × 10(7) M(-1)-1.9 × 10(8) M(-1).
- MeSH
- chemie farmaceutická metody MeSH
- dimerizace MeSH
- disulfidy chemie MeSH
- gama-cyklodextriny chemická syntéza chemie MeSH
- imatinib mesylát chemie MeSH
- kalorimetrie MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- krystalografie rentgenová MeSH
- kyselina lithocholová chemie MeSH
- kyslík chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární konformace MeSH
- rozpouštědla chemie MeSH
- steroidy chemie MeSH
- sulfhydrylové sloučeniny chemie MeSH
- termodynamika MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
