Single-benzene fluorophores are bright and the smallest fluorochromes known so far. In single-benzene fluorophores, the fluorescence is mediated by the push/pull effect of substituting groups. ...Despite a plethora of advantageous properties, this group of molecules has not been extensively studied for design of high-performance fluorescent sensors of catalytic or enzymatic activities. Thus, herein, new fluorescent probes based on the Tsuji-Trost reaction were developed for the selective detection of palladium and other transition metals (platinum and gold) in an aqueous/organic mixed solvent with the sensitivity down to 2.5 nM (for palladium). The relative flexibility in the synthesis of these probes allows for facile color tuning of the emitted fluorescence. In this study, we have successfully utilized a yellow emission variant for sensitive detection of palladium under cell-free conditions and in living cells, validating its possible applicability for high-throughput optical sensing of catalysts for bioorthogonal chemistry under physiological conditions.
New fluorescent probes based on the Tsuji-Trost reaction were developed for the selective detection of palladium and other transition metals (platinum and gold) in an aqueous/organic mixed solvent with a sensitivity down to 2.5 nM (for palladium).
Allyl- and propargyl ethers of umbelliferone are sensitive probes for palladium and platinum, including anticancer compounds cisplatin, carboplatin and oxaliplatin, and effective for direct ...visualization of protein and DNA complexes with organometallic compounds in polyacrylamide gels allowing easy detection of interactions with analyzed protein or nucleic acid. Both probes can be used for fast evaluation of Pd/Pt binding to nanocarriers relevant in drug targeted therapy or specific clinically relevant target macromolecules.
Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the ...major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2–associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the “tonic” AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.
•GAB1 upregulation in an intraclonal subpopulation of peripheral blood CLL cells leads to tonic AKT activity and increased homing capacity.•FoxO1-GAB1-pAKT axis can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition.
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Sustainable Business Fischer, Manuel; Foord, Daniel; Frecè, Jan ...
2023, 2023.
eBook
Odprti dostop
This open access book is a compact guide to the development of sustainable business, which has become the central concept in discussions about the future development of humanity and planet earth. It ...provides basic terminology and concepts on sustainable business and offers insights into a new management paradigm that integrates social and environmental dimensions into business models, strategies, and operations. New business concepts such as the donut economy, the circular economy, social innovation and sustainable leadership are introduced and the book outlines how they influence the way we run businesses today and in the future. This book lays the foundation for new management thinking in business and academia, making it a essential reader for professionals and students alike.
The reductive discoloration of azo dye, Congo red, catalyzed by noble metal nanoparticles was used to visualize protein-metal complexes in native polyacrylamide gels after counterstaining with ...Coomassie blue. This technique was used to characterize the synthesis of palladium, rhodium and iridium nanoparticles encapsulated in Pyrococcus furiosus ferritin.
The membrane impermeable luciferase substrate furimazine is outside of the virus-like particles while the reporter enzyme is enclosed inside the viral membrane. While the membrane is intact, the ...substrate remains separated from the luciferase. After the membrane integrity is compromised by the antimicrobial peptide, a pore is formed that allows an ingress of the substrate to the inside of virus like particle. The substrate gets in contact with the enzyme and furimazine chemical conversion is accompanied by the light emission that can be easily detected.
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•Virolytic assay for pore forming peptides based on Ebola virus-like particles.•Applicability to search for Ebola and Marburg virus inactivating compounds.•Systematic comparison of pore forming peptides in hemolytic and virolytic assays.•Cecropin A/Melittin hybrid (CAM-W) destroys infectivity of lentiviruses.•CAM-W effectively lyses Ebola virus-like particles at micromolar concentrations.
Antimicrobial peptides are currently considered as promising antiviral compounds. Current assays to evaluate the effectivity of peptides against enveloped viruses based on liposomes or hemolysis are encumbered by the artificial nature of liposomes or distinctive membrane composition of used erythrocytes. We propose a novel assay system based on enzymatic Ebola virus-like particles containing sensitive luciferase reporter. The assay was validated with several cationic and anionic peptides and compared with lentivirus inactivation and hemolytic assays. The assay is sensitive and easy to perform in standard biosafety level laboratory with potential for high-throughput screens. The use of virus-like particles in the assay provides a system as closely related to the native viruses as possible eliminating some issues associated with other more artificial set ups.
We have identified CAM-W (KWKLWKKIEKWGQGIGAVLKWLTTWL) as a peptide with the greatest antiviral activity against infectious lentiviral vectors and filoviral virus-like particles.
The reductive discoloration of azo dye, Congo red, catalyzed by noble metal nanoparticles was used to visualize protein-metal complexes in native polyacrylamide gels after counterstaining with ...Coomassie blue. This technique was used to characterize the synthesis of palladium, rhodium and iridium nanoparticles encapsulated in
Pyrococcus furiosus
ferritin.
Direct visualization of proteins and the catalytic activity of metal nanoparticles from metal-protein complexes in native polyacrylamide gels.
As highlighted by recent pandemic outbreaks, antiviral drugs are crucial resources in the global battle against viral diseases. Unfortunately, most antiviral drugs are characterized by a plethora of ...side effects and low efficiency/poor bioavailability owing to their insolubility. This also applies to the arylnaphthalide lignin family member, diphyllin (Diph). Diph acts as a vacuolar ATPase inhibitor and has been previously identified as a promising candidate with broad-spectrum antiviral activity. However, its physicochemical properties preclude its efficient administration in vivo, complicating preclinical testing.
We produced human recombinant
- ferritin (HsaFtH) and used it as a delivery vehicle for Diph encapsulation through pH-mediated reversible reassembly of HsaFtH. Diph nanoformulation was subsequently thoroughly characterized and tested for its non-target cytotoxicity and antiviral efficiency using a panel of pathogenic viral strain.
We revealed that loading into HsaFtH decreased the undesired cytotoxicity of Diph in mammalian host cells. We also confirmed that encapsulated Diph exhibited slightly lower antiviral activity than free Diph, which may be due to the differential uptake mechanism and kinetics of free Diph and Diph@HsaFtH. Furthermore, we confirmed that the antiviral effect was mediated solely by Diph with no contribution from HsaFtH.
It was confirmed that HsaFtH is a suitable vehicle that allows easy loading of Diph and production of highly homogeneous nanoparticles dispersion with promising broad-spectrum antiviral activity.
•Reversible reassembly properties of four different types of ferritins were studied.•For all examined ferritins, disassembly is faster in acidic pH than in basic pH.•Archaeal Pfu ferritin is the most ...stable in both, acidic and basic conditions.•All ferritins form protein corona hampering their cellular uptake.•For all ferritins, kidney/liver are the preferential bioaccumulation sites.
Understanding the reversible reassembly properties of ferritins (FRTs) is crucial for enabling their applicability in nanomedicine. These properties include drug loading capabilities and also subsequent payload release in desired site-of-action. Thus, the presented study is focused on understanding the disassembly of recombinantly produced FRTs of varying origin and subunit composition, i.e. equine FRT composed of 22 L- and 2 H-subunits (EcaLH) or 24 L-subunits (EcaL), human FRT composed of 24 H-subunits (HsaH) and archaeal Pyrococcus furiosus FRT (Pfu). Disassembly was distinctly influenced by pH and ionic strength. Except for Pfu, the disassembly kinetics in acidic pH is rapid upon reaching an innate threshold, reaching the final state within minutes. Disassembly kinetics in basic pH is slower. Pfu is partially disassembled within the entire pH range. While equine FRT disassembles into free subunits, HsaH disassembles into subunit clusters. EcaL and Pfu form large aggregates during disassembly in mildly acidic pH, although basic pH causes partial disassembly without aggregation, suggesting usability for basic pH-triggered drug loading. We show that in human serum/plasma, FRTs readily form protein corona, hampering their uptake. Interestingly, we found out that archaeal Pfu likely exhibits similar receptor affinity as mammalian FRTs. Further, in vivo toxicity and biodistribution study of a single dose of FRTs demonstrated very low toxicity of FRTs and their preferential liver/kidney bioaccumulation.
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Ceria nanoparticles can catalyze many redox reactions that resemble reactions catalyzed by naturally occurring enzymes, such as peroxidase, catalase, haloperoxidase or phosphatase. This makes ...nanoceria an attractive material for biomedical and sensing applications. Presence of detergents dramatically affects the catalytic activity of nanoceria. The catalytic activity is also strongly influenced by biogenic compounds present in the sample. Furthermore, biomedical applications are hindered by the difficulties to detect nanoceria uptake by cells. Therefore, we have developed a new fast and sensitive fluorescent haloperoxidase assay based on fluorescein bromination in presence of CTAB to detect uptake of CeO2 nanoparticles by cells in vitro. Moreover, catalytic activities of standard nanoceria (CeO2) were compared to nanoceria hydrates (CeO2.xH2O) that are easier for preparation and might be stabilized by biologically relevant molecules allowing for a specific targeting to cells or tissues. We have developed a new approach to produce CeO2.xH2O in presence of TEMED and analyzed whether the presence of H2O2 during the synthesis influences the catalytic activity of produced particles.
Ceria hydrate NPs are produced from common precursor in presence of TEMED. Synthesized NPs possess, among others, haloperoxidase activity that is blocked by biogenic phosphates but can be restored by cationic detergents and used for detection of ceria in fixed cells.ABTS, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid); AOT, dioctyl sulfosuccinate sodium salt; BZ, benzalkonium chloride; CTAB, cetyltrimethylammonium bromide; CB, Celestine blue; DOC, sodium deoxycholate; EO, eosin Y; FCS, fetal calf serum; FL, fluorescein; NC, nanoceria; NCH, nanoceria hydrate; NP, nanoparticle; PBS, phosphate buffered saline; pNPP, p‐nitrophenol phosphate; PR, phenol red; PXRD, powder X‐ray diffraction; SDS, sodium dodecylsulfate; SOD, superoxide dismutase; TB, thymol blue; TBAB, tetrabutyl ammonium bromide; TEA, triethanol amine; TEMED, tetramethylenediamine; TMB, tetramethyl benzidine; Tw20, Tween 20; TX100, Triton X‐100.
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