Peptide display methods are a powerful tool for discovering new ligands of pharmacologically relevant targets. However, the selected ligands often suffer from low affinity. Using phage display, we identified a new bicyclic peptide binder of prostate-specific membrane antigen (PSMA), a metalloprotease frequently overexpressed in prostate cancer. We show that linking multiple copies of a selected low-affinity peptide to a biocompatible water-soluble N-(2-hydroxypropyl)methacrylamide copolymer carrier (iBody) improved binding of the conjugate by several orders of magnitude. Furthermore, using ELISA, enzyme kinetics, confocal microscopy, and other approaches, we demonstrate that the resulting iBody can distinguish between different conformations of the target protein. The possibility to develop stable, fully synthetic, conformation-selective antibody mimetics has potential applications for molecular recognition, diagnosis and treatment of many pathologies. This strategy could significantly contribute to more effective drug discovery and design.
- MeSH
- biomimetické materiály chemie MeSH
- kalikreiny chemie MeSH
- lidé MeSH
- nosiče léků chemie MeSH
- peptidová knihovna * MeSH
- prostatický specifický antigen chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Coronavirus disease 2019 (COVID-19) has spread rapidly throughout the globe. The spectrum of disease is broad but among hospitalized patients with COVID-19, respiratory failure from acute respiratory distress syndrome is the leading cause of mortality. There is an urgent need for an effective treatment. The current focus has been developing novel therapeutics, including antivirals, protease inhibitors, vaccines and targeting the overactive cytokine response with anti-cytokine therapy. The overproduction of early response proinflammatory cytokines results in what has been described as a "cytokine storm" is leading eventually to death when the cells fail to terminate the inflammatory response. Accumulating evidence shows that inflammatory cytokines induce selectin ligands that play a crucial role in the pathogenesis of inflammatory diseases by mediating leukocyte migration from the blood into the tissue. Thus, the selectins and selectin ligands represent a promising therapeutic target for the treatment of COVID-19. In this paper, potential pan-selectin inhibitors were identified employing a virtual screening using a docking procedure. For this purpose, the Asinex and ZINC databases of ligands, including approved drugs, biogenic compounds and glycomimetics, altogether 923,602 compounds, were screened against the P-, L- and E-selectin. At first, the experimentally confirmed inhibitors were docked into all three selectins' carbohydrate recognition domains to assess the suitability of the screening procedure. Finally, based on the evaluation of ligands binding, we propose 10 purchasable pan-selectin inhibitors to develop COVID-19 therapeutics.
- MeSH
- antivirové látky chemie MeSH
- biomimetické materiály chemie MeSH
- chemické databáze * MeSH
- COVID-19 farmakoterapie MeSH
- lidé MeSH
- počítačová simulace * MeSH
- preklinické hodnocení léčiv MeSH
- SARS-CoV-2 chemie metabolismus MeSH
- selektiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Purpose: Nanomaterials for antimicrobial applications have gained interest in recent years due to the increasing bacteria resistance to conventional antibiotics. Wound sterilization, water treatment and surface decontamination all avail from multifunctional materials that also possess excellent antibacterial properties, eg zinc oxide (ZnO). Here, we assess and compare the effects of synthesized hedgehog-like ZnO structures and commercial ZnO particles with and without mixing on the inactivation of bacteria on surfaces and in liquid environments. Methods: Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in microbial culture medium were added to reverse spin bioreactors that contained different concentrations of each ZnO type to enable dynamic mixing of the bacteria-ZnO suspensions. Optical density of the bacteria-ZnO suspensions was measured in real-time and the number of viable bacteria after 24 h exposure was determined using standard microbiological techniques. The concentration of zinc ion generated from ZnO dissolution in different liquid types was estimated from the dynamic interaction exposure. Static antibacterial tests without agitation in liquid media and on agar surface were performed for comparison. Results: A correlation between increasing ZnO particle concentration and reduction in viable bacteria was not monotonous. The lowest concentration tested (10 µg/mL) even stimulated bacteria growth. The hedgehog ZnO was significantly more antibacterial than commercial ZnO particles at higher concentrations (up to 1000 µg/mL tested), more against E. coli than S. aureus. Minimum inhibitory concentration in microwell plates was correlated with those results. No inhibition was detected for any ZnO type deposited on agar surface. Zinc ion release was greatly suppressed in cultivation media. Scanning electron microscopy images revealed that ZnO needles can pierce membrane of bacteria whereas the commercial ZnO nanoparticles rather agglomerate on the cell surface. Conclusion: The inhibition effects are thus mainly controlled by the interaction dynamics between bacteria and ZnO, where mixing greatly enhances antibacterial efficacy of all ZnO particles. The efficacy is modulated also by ZnO particle shapes, where hedgehog ZnO has superior effect, in particular at lower concentrations. However, at too low concentrations, ZnO can stimulate bacteria growth and must be thus used with caution.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- biomimetické materiály chemie farmakologie MeSH
- Escherichia coli účinky léků růst a vývoj MeSH
- ježkovití * MeSH
- mikrobiální testy citlivosti MeSH
- oxid zinečnatý chemie farmakologie MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Galectin-3 plays a crucial role in cancerogenesis; its targeting is a prospective pathway in cancer diagnostics and therapy. Multivalent presentation of glycans was shown to strongly increase the affinity of glycoconjugates to galectin-3. Further strengthening of interaction with galectin-3 may be accomplished using artificial glycomimetics with apt aryl substitutions. We established a new, as yet undescribed chemoenzymatic method to produce selective C-3-substituted N,N'-diacetyllactosamine glycomimetics and coupled them to human serum albumin. From a library of enzymes, only β-N-acetylhexosaminidase from Talaromyces flavus was able to efficiently synthesize the C-3-propargylated disaccharide. Various aryl residues were attached to the functionalized N,N'-diacetyllactosamine via click chemistry to assess the impact of the aromatic substitution. In ELISA-type assays with galectin-3, free glycomimetics exhibited up to 43-fold stronger inhibitory potency to Gal-3 than the lactose standard. Coupling to human serum albumin afforded multivalent neo-glycoproteins with up to 4209-fold increased inhibitory potency per glycan compared to the monovalent lactose standard. Surface plasmon resonance brought further information on the kinetics of galectin-3 inhibition. The potential of prepared neo-glycoproteins to target galectin-3 was demonstrated on colorectal adenocarcinoma DLD-1 cells. We investigated the uptake of neo-glycoproteins into cells and observed limited non-specific transport into the cytoplasm. Therefore, neo-glycoproteins primarily act as efficient scavengers of exogenous galectin-3 of cancer cells, inhibiting its interaction with the cell surface, and protecting T-lymphocytes against galectin-3-induced apoptosis. The present neo-glycoproteins combine the advantage of a straightforward synthesis, selectivity, non-toxicity, and high efficiency for targeting exogenous galectin-3, with possible application in the immunomodulatory treatment of galectin-3-overexpressing cancers.
- MeSH
- biomimetické materiály chemická syntéza chemie farmakologie MeSH
- galektiny antagonisté a inhibitory genetika metabolismus MeSH
- glykoproteiny chemie metabolismus MeSH
- kinetika MeSH
- krevní proteiny antagonisté a inhibitory genetika metabolismus MeSH
- lidé MeSH
- molekulární struktura MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The cell membrane is mainly composed of lipid bilayers with inserted proteins and carbohydrates. Lipid bilayers made of purified or synthetic lipids are widely used for estimating the effect of target compounds on cell membranes. However, the composition of such biomimetic membranes is much simpler than the composition of biological membranes. Interactions between compounds and simple composition biomimetic membranes might not demonstrate the effect of target compounds as precisely as membranes with compositions close to real organisms. Therefore, the aim of our study is to construct biomimetic membrane closely mimicking the state of natural membranes. Liposomes were prepared from lipids extracted from L-α-phosphatidylcholine, Escherichia coli, yeast (Saccharomyces cerevisiae) and bovine liver cells through agitation and sonication. They were immobilized onto silicon dioxide (SiO2) sensor surfaces using N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid buffer with calcium chloride. The biomimetic membranes were successfully immobilized onto the SiO2 sensor surface and detected by nanoplasmonic sensing. The immobilized membranes were exposed to choline carboxylates. The membrane disruption effect was, as expected, more pronounced with increasing carbohydrate chain length of the carboxylates. The results correlated with the toxicity values determined using Vibrio fischeri bacteria. The yeast extracted lipid membranes had the strongest response to introduction of choline laurate while the bovine liver lipid extracted liposomes were the most sensitive towards the shorter choline carboxylates. This implies that the composition of the cell membrane plays a crucial role upon interaction with choline carboxylates, and underlines the necessity of testing membrane systems of different origin to obtain an overall image of such interactions.
- MeSH
- biomimetické materiály chemie MeSH
- buněčná membrána chemie MeSH
- cholin analogy a deriváty MeSH
- liposomy chemie MeSH
- membránové lipidy chemie MeSH
- Saccharomyces cerevisiae MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Human cathepsin D (CatD), a pepsin-family aspartic protease, plays an important role in tumor progression and metastasis. Here, we report the development of biomimetic inhibitors of CatD as novel tools for regulation of this therapeutic target. We designed a macrocyclic scaffold to mimic the spatial conformation of the minimal pseudo-dipeptide binding motif of pepstatin A, a microbial oligopeptide inhibitor, in the CatD active site. A library of more than 30 macrocyclic peptidomimetic inhibitors was employed for scaffold optimization, mapping of subsite interactions, and profiling of inhibitor selectivity. Furthermore, we solved high-resolution crystal structures of three macrocyclic inhibitors with low nanomolar or subnanomolar potency in complex with CatD and determined their binding mode using quantum chemical calculations. The study provides a new structural template and functional profile that can be exploited for design of potential chemotherapeutics that specifically inhibit CatD and related aspartic proteases.
- MeSH
- biomimetické materiály chemická syntéza chemie metabolismus toxicita MeSH
- Caco-2 buňky MeSH
- cyklické peptidy chemická syntéza chemie metabolismus toxicita MeSH
- enzymatické testy MeSH
- inhibitory proteas chemická syntéza chemie metabolismus toxicita MeSH
- kathepsin D antagonisté a inhibitory chemie metabolismus MeSH
- kinetika MeSH
- lidé MeSH
- molekulární struktura MeSH
- pepstatiny chemie MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Strigolactones (SLs) constitute a new class of plant hormones of increasing importance in plant science. The structure of natural SLs is too complex for ready access by synthesis. Therefore, much attention is being given to design of SL analogues and mimics with a simpler structure but with retention of bioactivity. Here new hybrid type SL mimics have been designed derived from auxins, the common plant growth regulators. Auxins were simply coupled with the butenolide D-ring using bromo (or chloro) butenolide. D-rings having an extra methyl group at the vicinal C-3' carbon atom, or at the C-2' carbon atom, or at both have also been studied. The new hybrid type SL mimics were bioassayed for germination activity of seeds of the parasitic weeds S. hermonthica, O. minor and P. ramosa using the classical method of counting germinated seeds and a colorimetric method. For comparison SL mimics derived from phenyl acetic acid were also investigated. The bioassays revealed that mimics with a normal D-ring had appreciable to good activity, those with an extra methyl group at C-2' were also appreciably active, whereas those with a methyl group in the vicinal C-3' position were inactive (S. hermonthica) or only slightly active. The new hybrid type mimics may be attractive as potential suicidal germination agents in agronomic applications.
- MeSH
- biomimetické materiály chemická syntéza chemie farmakologie MeSH
- klíčení účinky léků MeSH
- kyseliny indoloctové chemická syntéza chemie farmakologie MeSH
- laktony chemická syntéza chemie farmakologie MeSH
- molekulární struktura MeSH
- plevel účinky léků růst a vývoj MeSH
- racionální návrh léčiv MeSH
- regulátory růstu rostlin chemická syntéza chemie farmakologie MeSH
- stabilita léku MeSH
- Publikační typ
- časopisecké články MeSH
Flavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.
As a part of ongoing activities towards the design of ligands against pathogenic lectins, a synthesis of original α-C-galacto/α-C-manno/α-C-fucopyranosyl glycomimetics based on a calix[4]arene scaffold and their binding evaluation is described. The interactions of the glycomimetics with seven lectins of various origins were carried out using agglutination inhibition assays. The 1,3-alternate tetra-C-fucosylated ligand and its derivative having a tertBu group at the upper rim of the calix[4]arene scaffold were the most potent towards the AAL lectin family (RSL, AFL, AAL, AOL) and BC2L-C. As AFL and RSL originate from important human (Aspergillus fumigatus) and plant (Ralstonia solanacearum) pathogens, the inhibition potency of both leading structures was assessed by surface plasmon resonance. With AFL, both structures exhibited an approximately three orders of magnitude increase in affinity compared to the reference l-fucose. The role of tertBu groups as "aglycon-assisted" events was illustrated by NMR. Furthermore, both compounds showed significantly increased ability to inhibit BC2L-C (from human pathogen Burkholderia cenocepacia) cell agglutination and were able to cross-link whole B. cenocepacia cells. Although the ligands failed to significantly inhibit the agglutination activity of LecA and LecB from Pseudomonas aeruginosa, tetra-C-galactosylated calix[4]arene with tertBu groups at the upper rim of the 1,3-alternate conformation inhibited P. aeruginosa biofilm formation efficiently. This systematic and comprehensive study highlights the fact that hydrolytically stable polyvalent C-glycomimetics should be regarded as potent and selective ligands capable of acting as antiadhesive agents.
- MeSH
- aglutinace účinky léků MeSH
- biofilmy účinky léků MeSH
- biomimetické materiály chemie farmakologie MeSH
- kalixareny chemie farmakologie MeSH
- lektiny chemie MeSH
- lidé MeSH
- ligandy MeSH
- molekulární konformace MeSH
- molekulární modely MeSH
- Pseudomonas aeruginosa účinky léků fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The C-type lectin DC-SIGN expressed on immature dendritic cells is a promising target for antiviral drug development. Previously, we have demonstrated that mono- and divalent C-glycosides based on d-manno and l-fuco configurations are promising DC-SIGN ligands. Here, we described the convergent synthesis of C-glycoside dendrimers decorated with 4, 6, 9, and 12 α-l-fucopyranosyl units and with 9 and 12 α-d-mannopyranosyl units. Their affinity against DC-SIGN was assessed by surface plasmon resonance (SPR) assays. For comparison, parent O-glycosidic dendrimers were synthesized and tested, as well. A clear increase of both affinity and multivalency effect was observed for C-glycomimetics of both types (mannose and fucose). However, when dodecavalent C-glycosidic dendrimers were compared, there was no difference in affinity regarding the sugar unit (l-fuco, IC50 17 μM; d-manno, IC50 12 μM). For the rest of glycodendrimers with l-fucose or d-mannose attached by the O- or C-glycosidic linkage, C-glycosidic dendrimers were significantly more active. These results show that in addition to the expected physiological stability, the biological activity of C-glycoside mimetics is higher in comparison to the corresponding O-glycosides and therefore these glycomimetic multivalent systems represent potentially promising candidates for targeting DC-SIGN.
- MeSH
- biomimetické materiály chemie farmakologie MeSH
- fukosa chemie MeSH
- inhibiční koncentrace 50 MeSH
- lektiny typu C antagonisté a inhibitory MeSH
- mannosa chemie MeSH
- molekuly buněčné adheze antagonisté a inhibitory MeSH
- receptory buněčného povrchu antagonisté a inhibitory MeSH
- Publikační typ
- časopisecké články MeSH
