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FLEX: genetically encodable enzymatic fluorescence signal amplification using engineered peroxidase.Cell Chemical Biology Mar 2024Fluorescent tagging of biomolecules enables their sensitive detection during separation and determining their subcellular location. In this context, peroxidase-based...
Fluorescent tagging of biomolecules enables their sensitive detection during separation and determining their subcellular location. In this context, peroxidase-based reactions are actively utilized for signal amplification. To harness this potential, we developed a genetically encodable enzymatic fluorescence signal amplification method using APEX (FLEX). We synthesized a fluorescent probe, Jenfluor triazole (JFT1), which effectively amplifies and restricts fluorescence signals under fixed conditions, enabling fluorescence-based detection of subcellularly localized electron-rich metabolites. Moreover, JFT1 exhibited stable fluorescence signals even under osmium-treated and polymer-embedded conditions, which supported findings from correlative light and electron microscopy (CLEM) using APEX. Using various APEX-conjugated proteins of interest (POIs) targeted to different organelles, we successfully visualized their localization through FLEX imaging while effectively preserving organelle ultrastructures. FLEX provides insights into dynamic lysosome-mitochondria interactions upon exposure to chemical stressors. Overall, FLEX holds significant promise as a sensitive and versatile system for fluorescently detecting APEX2-POIs in multiscale biological samples.
PubMed: 38513646
DOI: 10.1016/j.chembiol.2024.02.007 -
Science Progress 2024Termites cause a serious menace to wooden structures all over the world. They rely mostly on entozoic fauna residing in their hindgut for the digestion of cellulosic and...
Termites cause a serious menace to wooden structures all over the world. They rely mostly on entozoic fauna residing in their hindgut for the digestion of cellulosic and hemicellulosic materials. One of the ways to control termites is through their gut symbionts. The present study was designed to characterize the hindgut bacteria isolated from and . Furthermore, the growth inhibitory effect of eight tropical plant extracts was investigated to find out potential control agents for these bacterial isolates. The characterization of bacteria was carried out based on their morphology, Gram staining, biochemical and amplification of 16SrRNA gene. Amplified products were sequenced to confirm their relationship with bacterial isolates from termites of other regions. The growth inhibitory effect of ethanolic leaf extracts of eight plants was evaluated in an invitro agar well diffusion method. Qualitative and quantitative phytochemical analysis of the most effective plant was carried out to learn about bioactive agents. The results confirmed the presence of five bacteria from each termite species. The , and were common to both termites whereas and were found in only and harbor and in addition to common three ones. Among the plant extracts of , , , and , the > were found to have growth inhibitory effects with increasing concentrations from 100 to 2000 µg/mL. The biodiversity of the bacterial fauna is important for the biological control of termites. Leaf extracts of these medicinal plants can be used to control termite infestation in an environment-friendly manner to save huge economic loss.
Topics: Animals; Isoptera; Bacteria; Plant Extracts; Biodiversity
PubMed: 38490163
DOI: 10.1177/00368504241236026 -
Molecules (Basel, Switzerland) Feb 2024A series of new chelating bidentate (SS) alkylimidazole-2-thione-Ru(II)/Os(II) complexes (, , , /, , ), and the tridentate (SNS)...
A series of new chelating bidentate (SS) alkylimidazole-2-thione-Ru(II)/Os(II) complexes (, , , /, , ), and the tridentate (SNS) pyridine-2,6-diylimidazole-2-thione-Ru(II)/Os(II) complexes (, /, , ) in the forms [M(cym)(L)Cl]PF and [M(cym)(L)]PF (M = Ru or Os, cym = η--cymene, and L = heterocyclic derivatives of thiourea) respectively, were successfully synthesized. Spectroscopic and analytical methods were used to characterize the complexes and their ligands. Solid-state single-crystal X-ray diffraction analyses revealed a "piano-stool" geometry around the Ru(II) or Os(II) centers in the respective complexes. The complexes were investigated for in vitro chemotherapeutic activities against human cervical carcinoma (HeLa) and the non-cancerous cell line (Hek293) using the MTT assay. The compounds , , , , , , and the reference drug, 5-fluorouracil were found to be selective toward the tumor cells; the compounds , , , , , and , which were found not to be selective between normal and tumor cell lines. The IC value of the tridentate half-sandwich complex (86 ± 9 μM) showed comparable anti-proliferative activity with the referenced commercial anti-cancer drug, 5-fluorouracil (87 ± 15 μM). The pincer (SNS) osmium complexes (36 ± 10 μM) and (40 ± 4 μM) were twice as effective as the reference drug 5-fluorouracil at the respective dose concentrations. However, the analogous pincer (SNS) ruthenium complex was ineffective and did not show anti-proliferative activity, even at a higher concentration of 147 ± 1 μM. These findings imply that the higher stability of the chelating (SS) and the pincer (SNS) ligand architectures in the complexes improves the biological (anti-proliferative) activity of the complexes by reducing the chance of ligand dissociation under physiological conditions. In general, the pincer (SNS) osmium complexes were found to be more cytotoxic than their ruthenium analogues, suggesting that the anti-proliferative activity of the imidazole-2-thione-Ru/Os complexes depends on the ligand's spatial coordination, the nature of the metal center, and the charge of the metal complex ions.
Topics: Humans; Ruthenium; Osmium; Ligands; HEK293 Cells; Thiones; Chelating Agents; Antineoplastic Agents; Coordination Complexes; Cell Line, Tumor; Fluorouracil; Cymenes
PubMed: 38474456
DOI: 10.3390/molecules29050944 -
ACS Omega Feb 2024To study transcriptome dynamics without harming cells, it is essential to convert chemical bases. 4-Thiouridine (4sU) is a biocompatible uridine analogue that can be...
To study transcriptome dynamics without harming cells, it is essential to convert chemical bases. 4-Thiouridine (4sU) is a biocompatible uridine analogue that can be converted into a cytidine analogue. Although several reactions can convert 4sU into a cytidine analogue, few studies have compared the features of these reactions. In this study, we performed three reported base conversion reactions, including osmium tetroxide, iodoacetamide, and sodium periodate treatment, as well as a new reaction using 2,4-dinitrofluorobenzene. We compared the reaction time, conversion efficacy, and effects on reverse transcription. These reactions successfully converted 4sU into a cytidine analogue quantitatively using trinucleotides. However, the conversion efficacy and effect on reverse transcription vary depending on the reaction with the RNA transcript. OsO treatment followed by NHCl treatment showed the best base-conversion efficiency. Nevertheless, each reaction has its own advantages and disadvantages as a tool for studying the transcriptome. Therefore, it is crucial to select the appropriate reaction for the target of interest.
PubMed: 38434802
DOI: 10.1021/acsomega.3c08516 -
Scientific Reports Feb 2024Testing the hemocompatibility of medical devices after their interaction with blood entails the need to evaluate the activation of blood elements and the degree of their...
Testing the hemocompatibility of medical devices after their interaction with blood entails the need to evaluate the activation of blood elements and the degree of their coagulation and adhesion to the device surface. One possible way to achieve this is to use scanning electron microscopy (SEM). The aim was to develop a novel SEM-based method to assess the thrombogenic potential of medical devices and their adhesiveness to blood cells. As a part of this task, also find a convenient procedure of efficient and non-destructive sample fixation for SEM while reducing the use of highly toxic substances and shortening the fixation time. A polymeric surgical mesh was exposed to blood so that blood elements adhered to its surface. Such prepared samples were then chemically fixed for a subsequent SEM measurement; a number of fixation procedures were tested to find the optimal one. The fixation results were evaluated from SEM images, and the degree of blood elements' adhesion was determined from the images using ImageJ software. The best fixation was achieved with the May-Grünwald solution, which is less toxic than chemicals traditionally used. Moreover, manipulation with highly toxic osmium tetroxide can be avoided in the proposed procedure. A convenient methodology for SEM image analysis has been developed too, enabling to quantitatively evaluate the interaction of blood with the surfaces of various medical devices. Our method replaces the subjective assessment of surface coverage with a better-defined procedure, thus offering more precise and reliable results.
Topics: Microscopy, Electron, Scanning; Histological Techniques; Osmium Tetroxide
PubMed: 38409219
DOI: 10.1038/s41598-024-55136-z -
Biology Feb 2024Mice lacking () manifest reduced trabecular bone mass. However, the impact of expression in osteoblasts in vivo remains understudied. Herein, we generated...
Mice lacking () manifest reduced trabecular bone mass. However, the impact of expression in osteoblasts in vivo remains understudied. Herein, we generated osteoblast-specific transgenic (Tg) mice expressing and characterized their skeletal phenotype. Micro-CT analyses of the distal metaphysis of the femur showed a 50% and a 38% increase in trabecular bone mass in Tg male and female mice, respectively, due to a significant increase in trabecular number and a reduction in trabecular separation. Histomorphometry and serum biomarker studies uncovered that increased trabecular bone mass in Tg mice was the consequence of enhanced bone formation. Accordingly, an abundance of bone formation (, ), but not bone resorption (), markers were augmented in the femurs of Tg mice. Since the trabecular bone density is known to inversely correlate with the amount of marrow adipose tissue (MAT), we measured the MAT in osmium-tetroxide-labeled bones by micro-CT scanning. We found 86% less MAT in the proximal tibia of the Tg males. Consistently, the expression levels of the adipogenic markers, and , were 50% lower in the femurs of the Tg males. Our data are consistent with the possibility that claudin11 exerts anabolic effects in osteoblastic lineage cells that act via promoting the differentiation of marrow stem cells towards osteoblasts at the expense of adipocytes.
PubMed: 38392326
DOI: 10.3390/biology13020108 -
Biomedicine & Pharmacotherapy =... Feb 2024Research into cancer therapeutics has uncovered various potential medications based on metal-containing scaffolds after the discovery and clinical applications of... (Review)
Review
Research into cancer therapeutics has uncovered various potential medications based on metal-containing scaffolds after the discovery and clinical applications of cisplatin as an anti-cancer agent. This has resulted in many metallodrugs that can be put into medical applications. These metallodrugs have a wider variety of functions and mechanisms of action than pure organic molecules. Although platinum-based medicines are very efficient anti-cancer agents, they are often accompanied by significant side effects and toxicity and are limited by resistance. Some of the most studied and developed alternatives to platinum-based anti-cancer medications include metallodrugs based on ruthenium, gold, copper, iridium, and osmium, which showed effectiveness against many cancer cell lines. These metal-based medicines represent an exciting new category of potential cancer treatments and sparked a renewed interest in the search for effective anti-cancer therapies. Despite the widespread development of metal complexes touted as powerful and promising in vitro anti-cancer therapeutics, only a small percentage of these compounds have shown their worth in vivo models. Metallodrugs, which are more effective and less toxic than platinum-based drugs and can treat drug-resistant cancer cells, are the focus of this review. Here, we highlighted some of the most recently developed Pt, Ru, Au, Cu, Ir, and Os complexes that have shown significant in vivo antitumor properties between 2017 and 2023.
Topics: Humans; Coordination Complexes; Neoplasms; Antineoplastic Agents; Cisplatin; Platinum
PubMed: 38290253
DOI: 10.1016/j.biopha.2024.116211 -
The Journal of Physical Chemistry. A Feb 2024Dye sensitizers with wideband absorption covering the near-IR region have long been of interest because they potentially harvest a wide range of solar energies essential...
Enhancing Near-Infrared Absorption in Terpyridyl Ru/Os Complexes with Ancillary Ligands to Activate Spin-Forbidden Transitions in Dye-Sensitized Solar Cells: A TDDFT Investigation.
Dye sensitizers with wideband absorption covering the near-IR region have long been of interest because they potentially harvest a wide range of solar energies essential to promote photocurrent power conversion efficiencies. In this study, we used time-dependent density functional theory with spin-orbit (SO) interactions to theoretically explore the long-wavelength absorptions and spin-forbidden triplet transitions activated by SO interactions for terpyridyl ruthenium/osmium complex dyes. These dyes feature a Ru(II) sensitizer coordinated with a phosphine ligand and are exemplified by DX1, denoted as [-dichloro-(phenyldimethoxyphosphine)(2,2';6',2″-terpyridyl-4,4',4″-tricarboxylic)Ru]. We found that ancillary ligands significantly affected the longest wavelength spin-allowed absorption, with NCS ligands yielding longer wavelength S transitions than halides. High atomic number halide ligands caused blue shifts in the S transition. Os complexes consistently exhibited longer wavelength S transitions than Ru complexes with identical ligands. In Ru/Os complexes, ancillary ligands with higher atomic numbers have a more pronounced effect in activating spin-forbidden triplet transitions through spin-orbit coupling (SOC) than those with lower atomic numbers. The absorption wavelength of the SOC-activated transition primarily depended on the energy of lower lying triplet states. Some complexes exhibited T states activated by SOC, leading to longer wavelength absorption than that of SOC-activated T states. Our study revealed the significance of ancillary ligands and SOC interactions in Ru/Os complexes, offering insights for optimizing materials with enhanced long-wavelength absorption properties, particularly in the near-IR range, for photovoltaic and optoelectronic applications.
PubMed: 38271995
DOI: 10.1021/acs.jpca.3c07554 -
Scientific Reports Dec 2023The Turonian age (~ 90-94 Ma) was the hottest geological interval in the Cretaceous and also marked by the K3 event, a pronounced enrichment of He in pelagic...
The Turonian age (~ 90-94 Ma) was the hottest geological interval in the Cretaceous and also marked by the K3 event, a pronounced enrichment of He in pelagic sediments (i.e., massive input of extraterrestrial materials). Here, we present Os isotopic (Os/Os) and platinum group element (PGE) data from Turonian sedimentary records. After a sharp unradiogenic shift during the end-Cenomanian oceanic anoxic event 2, the Os/Os ratios declined continuously throughout the Turonian, which could be ascribed to the formations of several large igneous provinces (LIPs). Because the interval with the most unradiogenic Os/Os ratios (i.e., enhanced LIP volcanism) does not correspond to the warmest interval during the mid-Cretaceous, additional sources of CO, such as subduction zone volcanism or the kimberlite formation, may explain the Cretaceous Thermal Maximum. As Os isotope ratios do not show any sharp unradiogenic shifts and PGE concentrations do not exhibit a pronounced enrichment, an influx of fine-grained cosmic dust to the Earth's surface, possibly from the long-period comet showers, can be inferred at the time of the He enrichment during the mid-Turonian K3 event. Our findings highlight the different behaviors of He and PGE information in the sedimentary rocks during the input of fined-grained extraterrestrial materials.
PubMed: 38086887
DOI: 10.1038/s41598-023-49252-5 -
Data in Brief Dec 2023This paper presents a dataset offering profound insights into the formation and physical properties of two-dimensional (2D) noble metals under various configurations,...
This paper presents a dataset offering profound insights into the formation and physical properties of two-dimensional (2D) noble metals under various configurations, with a primary focus on their role as catalysts for the hydrogen evolution reaction (HER). These data are of significant value to catalysis researchers, materials scientists, and computational chemists, providing them with a detailed understanding of 2D noble metals' behavior as catalysts and enabling advancements in their respective studies. The dataset, thoughtfully structured and meticulously documented, comprises five primary sections, each housing distinct content and analyses. It offers a comprehensive view of the substrate-mediated stabilization and physical properties of 2D noble metals, including silver (Ag), gold (Au), iridium (Ir), osmium (Os), palladium (Pd), platinum (Pt), rhodium (Rh), and ruthenium (Ru). The substrates utilized include bare Si-face 4H-SiC, buffer layer (BuL), and monolayer epitaxial graphene (MEG). The data collection process involves the use of the SIESTA code for density functional theory (DFT) calculations. The vdW-BH functional is consistently applied in conjunction with a double-ζ polarized (DZP) basis set, known for its reliability in capturing nuanced interactions with noble metals. Parameters such as an energy shift of 200 meV and a force tolerance of 0.02 eV/Å are meticulously configured for accurate results. In-depth structural information, including optimized structures in top and side views and Cartesian coordinates for various substrate-metal configurations, is a central component of the dataset. These structural details are pivotal for comprehending the physical properties of 2D noble metals. Furthermore, the dataset encompasses results from charge density difference (CDD) analyses, including cube files, planar-averaged CDD curves, and 3D CDD maps. These analyses provide essential data for understanding the electronic properties of these materials. The dataset also includes outcomes from charge population analyses utilizing Hirshfeld and Voronoi schemes. These analyses offer insights into structural parameters, Hirshfeld charge magnitudes on 2D metal layers, and various energy-related metrics, further enhancing the dataset's richness. In addition to structural data, the dataset presents atomic structures in top and side views of free-standing and substrate-supported 2D noble metals after hydrogen adsorption, along with corresponding Cartesian coordinates. Gibbs free energy (Δ) data for hydrogen adsorption on both free-standing and substrate-supported 2D noble metals contribute to the dataset's depth. This meticulously curated dataset not only serves as a valuable resource for researchers exploring the properties and behaviors of 2D noble metals but also holds significant reuse potential. Researchers can employ this dataset to validate their computational methods and models in catalysis research, enhancing the quality and reliability of their simulations. Furthermore, it serves as a possible educational tool, fostering hands-on learning for students and emerging researchers in the field of computational materials science and catalysis, thereby promoting methodological consistency within the scientific community.
PubMed: 38053595
DOI: 10.1016/j.dib.2023.109801