Non-Invasive Nanometer Resolution Assessment of Cell-Soft Hydrogel System Mechanical Properties by Scanning Ion Conductance Microscopy.

Biomimetic hydrogels have garnered increased interest due to their considerable potential for use in various fields, such as tissue engineering, 3D cell cultivation, and drug delivery. The primary challenge for applying hydrogels in tissue engineering is accurately evaluating their mechanical characteristics. In this context, we propose a method using scanning ion conductance microscopy (SICM) to determine the rigidity of living human breast cancer cells MCF-7 cells grown on a soft, self-assembled Fmoc-FF peptide hydrogel.

Mechanical properties of soft hydrogels: assessment by scanning ion-conductance microscopy and atomic force microscopy.

The growing interest in biomimetic hydrogels is due to their successful applications in tissue engineering, 3D cell culturing and drug delivery. The major characteristics of hydrogels include swelling, porosity, degradation rate, biocompatibility, and mechanical properties. Poor mechanical properties can be regarded as the main limitation for the use of hydrogels in tissue engineering, and advanced techniques for its precise evaluation are of interest.

Molecular mechanism of thiocyanate dehydrogenase at atomic resolution.

Some sulfur-oxidizing bacteria playing an important role in global geochemical cycles utilize thiocyanate as the sole source of energy and nitrogen. In these bacteria the process of thiocyanate into cyanate conversion is mediated by thiocyanate dehydrogenases - a recently discovered family of copper-containing enzymes with the three‑copper active site unique among the other copper proteins. To get a deeper insight into the structure and molecular mechanism of action of thiocyanate dehydrogenases we isolated, purified, and comprehensively characterized an enzyme from the bacterium Pelomicrobium methylotrophicum.

Diverse biophysical mechanisms in voltage-gated sodium channel Na1.4 variants associated with myotonia.

Mutations in SCN4A gene encoding Na1.4 channel α-subunit, are known to cause neuromuscular disorders such as myotonia or paralysis. Here, we study the effect of two amino acid replacements, K1302Q and G1306E, in the DIII-IV loop of the channel, corresponding to mutations found in patients with myotonia.

Detection of α-Galactosidase A Reaction in Samples Extracted from Dried Blood Spots Using Ion-Sensitive Field Effect Transistors.

Fabry disease is a lysosomal storage disorder caused by a significant decrease in the activity or absence of the enzyme α-galactosidase A. The diagnostics of Fabry disease during newborn screening are reasonable, due to the availability of enzyme replacement therapy. This paper presents an electrochemical method using complementary metal-oxide semiconductor (CMOS)-compatible ion-sensitive field effect transistors (ISFETs) with hafnium oxide-sensitive surfaces for the detection of α-galactosidase A activity in dried blood spot extracts.

Identification and Pathogenicity of Species Associated with Onion Basal Rot in the Moscow Region of Russian Federation.

Fusarium basal rot of onions causes large losses during storage of commercial production of onion bulbs, which in turn adversely affects the food market situation in the off-season period. There are no data on the composition of spp., which causes onion basal rot in the Russian Federation.

Trichlorobacter ammonificans, a dedicated acetate-dependent ammonifier with a novel module for dissimilatory nitrate reduction to ammonia.

Dissimilatory nitrate reduction to ammonia (DNRA) is a common biochemical process in the nitrogen cycle in natural and man-made habitats, but its significance in wastewater treatment plants is not well understood. Several ammonifying Trichlorobacter strains (former Geobacter) were previously enriched from activated sludge in nitrate-limited chemostats with acetate as electron (e) donor, demonstrating their presence in these systems. Here, we isolated and characterized the new species Trichlorobacter ammonificans strain G1 using a combination of low redox potential and copper-depleted conditions.

Extracellular Fe(III) reductase structure reveals a modular organization enabling S-layer insertion and electron transfer to insoluble substrates.

The thermophilic anaerobic Gram-positive bacterium Carboxydothermus ferrireducens utilizes insoluble Fe(III) oxides as electron acceptors in respiratory processes using an extracellular 11-heme cytochrome c OmhA as a terminal reductase. OmhA is able to transfer electrons to soluble and insoluble Fe(III) compounds, substrates of multiheme oxidoreductases, and soluble electron shuttles. The crystal structure of OmhA at 2.

Sensing Cells-Peptide Hydrogel Interaction In Situ via Scanning Ion Conductance Microscopy.

Peptide-based hydrogels were shown to serve as good matrices for 3D cell culture and to be applied in the field of regenerative medicine. The study of the cell-matrix interaction is important for the understanding of cell attachment, proliferation, and migration, as well as for the improvement of the matrix. Here, we used scanning ion conductance microscopy (SICM) to study the growth of cells on self-assembled peptide-based hydrogels.

Tunable Self-Assembled Peptide Hydrogel Sensor for Pharma Cold Supply Chain.

Defrost sensors are a crucial element for proper functioning of the pharmaceutical cold chain. In this paper, the self-assembled peptide-based hydrogels were used to construct a sensitive defrost sensor for the transportation and storage of medications and biomaterials. The turbidity of the peptide hydrogel was employed as a marker of the temperature regime.

Unusual Cytochrome 552 from : Solution NMR Structure and Interaction with Thiocyanate Dehydrogenase.

The search of a putative physiological electron acceptor for thiocyanate dehydrogenase (TcDH) newly discovered in the thiocyanate-oxidizing bacteria revealed an unusually large, single-heme cytochrome (CytC552), which was co-purified with TcDH from the periplasm. Recombinant CytC552, produced in as a mature protein without a signal peptide, has spectral properties similar to the endogenous protein and serves as an in vitro electron acceptor in the TcDH-catalyzed reaction. The CytC552 structure determined by NMR spectroscopy reveals significant differences compared to those of the typical class I bacterial cytochromes : a high solvent accessible surface area for the heme group and so-called "intrinsically disordered" nature of the histidine-rich N- and C-terminal regions.

[Comprehensive medical rehabilitation using therapeutic physical factors including hydrokinesiotherapy in a pool with mineral water and its effect on circadian rhythms of arterial pressure and autonomic regulation in patients with arterial hypertension and with chronic psychoemotional stress].

Objective: To study the effect of the course-based comprehensive rehabilitation using the therapeutic physical factors of the Belokurikha resort, including hydrokinesiotherapy in a pool with mineral water on the circadian rhythms of arterial pressure and its autonomous regulation in patients with arterial hypertension (AH) associated with chronic psychoemotional stress (CPES).

Material And Methods: The study involved 83 patients with stage I-II grade 1-2 of AH, whose professional activities were associated with CPES. Each participant had 24-hours Holter blood pressure monitored, and cardiointervalography (CIG) was performed before and after the medical rehabilitation course.

Catalytic Properties of Flavocytochrome c Sulfide Dehydrogenase from Haloalkaliphilic Bacterium Thioalkalivibrio paradoxus.

Flavocytochrome c sulfide dehydrogenase (FCC) is one of the central enzymes of the respiratory chain in sulfur-oxidizing bacteria. FCC catalyzes oxidation of sulfide and polysulfide ions to elemental sulfur accompanied by electron transfer to cytochrome c. The catalytically active form of the enzyme is a non-covalently linked heterodimer composed of flavin- and heme-binding subunits.

Octaheme nitrite reductase: The mechanism of intramolecular electron transfer and kinetics of nitrite bioelectroreduction.

Detailed impedance and voltammetric studies of hexameric octaheme nitrite reductase immobilized on carbon-based nanomaterials, specifically nanotubes and nanoparticles, were performed. Well-pronounced bioelectrocatalytic reduction of nitrite on enzyme-modified electrodes was obtained. Analysis of the impedance data indicated the absence of long-lived intermediates involved in the nitrite reduction.

Fluorescence Lifetime and Intensity of Thioflavin T as Reporters of Different Fibrillation Stages: Insights Obtained from Fluorescence Up-Conversion and Particle Size Distribution Measurements.

Thioflavin T (ThT) assay is extensively used for studying fibrillation kinetics in vitro. However, the differences in the time course of ThT fluorescence intensity and lifetime and other physical parameters of the system, such as particle size distribution, raise questions about the correct interpretation of the aggregation kinetics. In this work, we focused on the investigation of the mechanisms, which underlay the difference in sensitivity of ThT fluorescence intensity and lifetime to the formation of protein aggregates during fibrillation by the example of insulin and during binding to globular proteins.

Sulfur-mediated synthesis of unsymmetrically substituted N-aryl oxalamides by the cascade thioamidation/cyclocondensation and hydrolysis reaction.

A facile and straightforward synthesis of unsymmetrically substituted N-aryl oxalamides from 2,2'-biphenyldiamines, 2-chloroacetic acid derivatives, elemental sulfur, and water has been developed. This protocol is distinguished by efficiency in water under metal-free conditions for N-aryl oxalamides bearing a side-chain NH2-group; it can be adapted for scale-up synthesis. The scope and limitations of this transformation have been investigated.

Trinuclear copper biocatalytic center forms an active site of thiocyanate dehydrogenase.

Biocatalytic copper centers are generally involved in the activation and reduction of dioxygen, with only few exceptions known. Here we report the discovery and characterization of a previously undescribed copper center that forms the active site of a copper-containing enzyme thiocyanate dehydrogenase (suggested EC 1.8.

Synthesis of Dibenzo[,][1,3]Diazepines via Elemental Sulfur-Mediated Cyclocondensation of 2,2'-Biphenyldiamines with 2-Chloroacetic Acid Derivatives.

The three-component reaction of 2,2'-biphenyldiamines with 2-chloroacetic acid derivatives and elemental sulfur was developed for the practical synthesis of unknown 2-carboxamide-substituted dibenzo[,][1,3]diazepines. This protocol is distinguished by efficiency in water and good tolerance to functional groups and can be adapted to a large-scale synthesis. The chemoselective preparation of a variety of 2-,,-substituted dibenzo[,][1,3]diazepines was accomplished using the developed method.

Development of 1,3-thiazole analogues of imidazopyridines as potent positive allosteric modulators of GABA receptors.

Structure-activity relationship studies were conducted in the search for 1,3-thiazole isosteric analogs of imidazopyridine drugs (Zolpidem, Alpidem). Three series of novel γ-aminobutyric acid receptor (GABAR) ligands belonging to imidazo[2,1-b]thiazoles, imidazo[2,1-b][1,3,4]thiadiazoles, and benzo[d]imidazo[2,1-b]thiazoles were synthesized and characterized as active agents against GABAR benzodiazepine-binding site. In each of these series, potent compounds were discovered using a radioligand competition binding assay.

Comparative Genomics of HRh1 and sp. SCN-R1, Halophilic Chemolithoautotrophic Sulfur-Oxidizing Capable of Using Thiocyanate as Energy Source.

The genomes of and (formerly known as ) sp. SCN-R1, two gammaproteobacterial halophilic sulfur-oxidizing bacteria (SOB) capable of thiocyanate oxidation via the "cyanate pathway", have been analyzed with a particular focus on their thiocyanate-oxidizing potential and sulfur oxidation pathways. Both genomes encode homologs of the enzyme thiocyanate dehydrogenase (TcDH) that oxidizes thiocyanate via the "cyanate pathway" in members of the haloalkaliphilic SOB of the genus However, despite the presence of conservative motives indicative of TcDH, the putative TcDH of the halophilic SOB have a low overall amino acid similarity to the enzyme, and also the surrounding genes in the TcDH locus were different.

Structure of the Anti-C60 Fullerene Antibody Fab Fragment: Structural Determinants of Fullerene Binding.

The structure of the anti-C fullerene antibody Fab fragment (FabC) was solved by X-ray crystallography. The computer-aided docking of C into the antigen-binding pocket of FabC showed that binding of C to FabC is governed by the enthalpy and entropy; namely, by π-π stacking interactions with aromatic residues of the antigen-binding site and reduction of the solvent-accessible area of the hydrophobic surface of C. A fragment of the mobile CDR H3 loop located on the surface of FabC interferes with C binding in the antigen-binding site, thereby resulting in low antibody affinity for C.