Novel Hybrid Catalysts of Cysteine Proteases Enhanced by Chitosan and Carboxymethyl Chitosan Micro- and Nanoparticles.

Micro- and nanoparticles of chitosan and carboxymethyl chitosan were synthesized, both with and without ascorbic acid. Methods were developed to form complexes between these micro- and nanoparticles and plant proteases-ficin, papain, and bromelain. It was demonstrated that the activity of cysteine protease complexes with carboxymethyl chitosan micro- and nanoparticles was higher compared to those with chitosan micro- and nanoparticles.

Effect of Magnetite Nanoparticles on Human Blood Components.

The qualitative composition and zeta potential of magnetite nanoparticles (size 4.2±1.2 nm) obtained by co-precipitation method were determined by X-ray and diffraction dynamic light scattering.

The Low-Waste Grafting Copolymerization Modification of Chitosan Is a Promising Approach to Obtaining Materials for Food Applications.

Chitosan takes second place of the most abundant polysaccharides naturally produced by living organisms. Due to its abundance and unique properties, such as its polycationic nature, ability to form strong elastic porous films, and antibacterial potential, it is widely used in the food industry and biomedicine. However, its low solubility in both water and organic solvents makes its application difficult.

Thermal Inactivation, Denaturation and Aggregation Processes of Papain-Like Proteases.

The investigation into the behavior of ficin, bromelain, papain under thermal conditions holds both theoretical and practical significance. The production processes of medicines and cosmetics often involve exposure to high temperatures, particularly during the final product sterilization phase. Hence, it's crucial to identify the "critical" temperatures for each component within the mixture for effective technological regulation.

The Effect of Ficin Immobilized on Carboxymethyl Chitosan on Biofilms of Oral Pathogens.

In the last decade, Ficin, a proteolytic enzyme extracted from the latex sap of the wild fig tree, has been widely investigated as a promising tool for the treatment of microbial biofilms, wound healing, and oral care. Here we report the antibiofilm properties of the enzyme immobilized on soluble carboxymethyl chitosan (CMCh) and CMCh itself. Ficin was immobilized on CMCh with molecular weights of either 200, 350 or 600 kDa.

Novel biocatalysts based on enzymes in complexes with nano- and micromaterials.

In today's world, there is a wide array of materials engineered at the nano- and microscale, with numerous applications attributed to these innovations. This review aims to provide a concise overview of how nano- and micromaterials are utilized for enzyme immobilization. Enzymes act as eco-friendly biocatalysts extensively used in various industries and medicine.

Mechanisms of UV-induced human lymphocyte apoptosis.

The article reviews the results of the studies of marker parameters (indicators) of various pathways and mechanisms of apoptosis of lymphocytes in donor peripheral blood induced by UV light (240-390 nm) in doses of 151, 1510, and 3020 J/m. The article analyses the processes of DNA fragmentation, distortion of the structural asymmetry of the cell membranes, changes in the degree of DNA damage (single-strand breaks), transcriptional factor р53, cytochrome , Fas receptors (CD95), caspase-3, caspase-8, and caspase-9, reactive oxygen species, and calcium ions in UV modified cells. The study determined that programmed cell death of lymphocytes after UV irradiation with 1510 J/m involves the р53-dependent pathway of the nuclear mechanism, as well as receptor-mediated caspase mechanism, mitochondrial mechanism, and the mechanism associated with the defects in calcium homeostasis.

The Effect of Polyene Antibiotic Amphotericin B on Erythrocyte Cytoarchitectonics and Osmotic Resistance.

We studied the effect of amphotericin B (2.5×10 and 5.4×10 M) on osmotic resistance and surface cytoarchitectonics of donor blood erythrocytes.

Complexation of Bromelain, Ficin, and Papain with the Graft Copolymer of Carboxymethyl Cellulose Sodium Salt and -Vinylimidazole Enhances Enzyme Proteolytic Activity.

This study investigates the features of interactions between cysteine proteases (bromelain, ficin, and papain) and a graft copolymer of carboxymethyl cellulose sodium salt with -vinylimidazole. The objective is to understand the influence of this interactions on the proteolytic activity and stability of the enzymes. The enzymes were immobilized through complexation with the carrier.

Carboxymethyl Cellulose-Based Polymers as Promising Matrices for Ficin Immobilization.

The present work is devoted to research on the interaction between carboxymethyl cellulose sodium salt and its derivatives (graft copolymer of carboxymethyl cellulose sodium salt and ,-dimethyl aminoethyl methacrylate) with cysteine protease (ficin). The interaction was studied by FTIR and by flexible molecular docking, which have shown the conjugates' formation with both matrices. The proteolytic activity assay performed with azocasein demonstrated that the specific activities of all immobilized ficin samples are higher in comparison with those of the native enzyme.

Novel Biocatalysts Based on Bromelain Immobilized on Functionalized Chitosans and Research on Their Structural Features.

Enzyme immobilization on various carriers represents an effective approach to improve their stability, reusability, and even change their catalytic properties. Here, we show the mechanism of interaction of cysteine protease bromelain with the water-soluble derivatives of chitosan-carboxymethylchitosan, -(2-hydroxypropyl)-3-trimethylammonium chitosan, chitosan sulfate, and chitosan acetate-during immobilization and characterize the structural features and catalytic properties of obtained complexes. Chitosan sulfate and carboxymethylchitosan form the highest number of hydrogen bonds with bromelain in comparison with chitosan acetate and -(2-hydroxypropyl)-3-trimethylammonium chitosan, leading to a higher yield of protein immobilization on chitosan sulfate and carboxymethylchitosan (up to 58 and 65%, respectively).

Novel Immobilized Biocatalysts Based on Cysteine Proteases Bound to 2-(4-Acetamido-2-sulfanilamide) Chitosan and Research on Their Structural Features.

Briefly, 2-(4-Acetamido-2-sulfanilamide) chitosan, which is a chitosan water-soluble derivative, with molecular weights of 200, 350, and 600 kDa, was successfully synthesized. The immobilization of ficin, papain, and bromelain was carried out by complexation with these polymers. The interaction mechanism of 2-(4-acetamido-2-sulfanilamide) chitosan with bromelain, ficin, and papain was studied using FTIR spectroscopy.

Expression Level of Membrane Markers CD5, CD19, and CD20 in B Cells after UV-Irradiation and Incubation in the Presence of Autologous Plasma.

The effect of UV-light (240-390 nm) in doses of 151 and 755 J/m on the expression of membrane markers CD5, CD19, CD20 in human peripheral blood B cells was studied by flow cytometry. In 24 h after exposure to UV light, we observed activation of processes accompanied by structural rearrangements of B-cell membranes leading to changes in the expression of receptor molecules: the content of of CD19 and CD20 increased due to activation of the synthesis of these proteins, while the content of CD5 decreased. The percentage of CD5 cells decreased over 24 h after UV-irradiation of lymphocytes, while addition of autologous plasma to the incubation medium produced a photoprotective effect on CD5 cells.

Biochemical Properties and Anti-Biofilm Activity of Chitosan-Immobilized Papain.

Chitosan, the product of chitin deacetylation, is an excellent candidate for enzyme immobilization purposes. Here we demonstrate that papain, an endolytic cysteine protease (EC: 3.4.

Silver Nanoparticles Induce Changes in the Structural and Functional Properties of Human Lymphocytes.

Exposure of human lymphocytes to silver nanoparticles (2-12 nm) reduced viability of cells and RNA, reduced activities of lactate dehydrogenase, glutathione reductase, and cytosolic calcium, increased ROS content in cells, affected surface architectonics of cells and changed hydrophobicity and charge of their plasma membranes. Silver nanoparticles triggered the process of cellular death by the mechanism of ETosis that is accompanied by chromatin release into the extracellular environment and formation of extracellular traps.

Novel biotechnological formulations of cysteine proteases, immobilized on chitosan. Structure, stability and activity.

Bromelain, papain, and ficin are studied the most for meat tenderization, but have limited application due to their short lifetime. The aim of this work is to identify the adsorption mechanisms of these cysteine proteases on chitosan to improve the enzymes' stability. It is known that immobilization can lead to a significant loss of enzyme activity, which we observed during the sorption of bromelain (protease activity compared to soluble enzyme is 49% for medium and 64% for high molecular weight chitosan), papain (34 and 28% respectively) and ficin (69 and 70% respectively).

Kinetically Determined Shapes of Grain Boundaries in Graphene.

A large-scale chemical synthesis of graphene produces a polycrystalline material with grain boundaries (GBs) that disturb the lattice structure and drastically affect material properties. An uncontrollable formation of GB can be detrimental, yet precise GB engineering can impart added functionalities onto graphene-and its noncarbon two-dimensional "cousins." While the importance of growth kinetics in shaping single-crystalline graphene islands has lately been appreciated, kinetics' role in determining a GB structure remains unaddressed.

Anti-biofilm and wound-healing activity of chitosan-immobilized Ficin.

Biofouling is among the key factors slowing down healing of acute and chronic wounds. Here we report both anti-biofilm and wound-healing properties of the chitosan-immobilized Ficin. The proposed chitosan-adsorption approach allowed preserving ~90% of the initial total activity of the enzyme (when using azocasein as a substrate) with stabilization factor of 4.

Flexoelectricity and Charge Separation in Carbon Nanotubes.

The effect of flexoelectric voltage on the electronic and optical properties of single- and double-wall carbon nanotubes is evaluated by the first-principles calculations. The voltage between the inner channel of curved carbon nanostructures and their surroundings scales linearly with nanotube wall curvature and can be boosted/reversed by appropriate outer wall functionalization. We predict and verify computationally that in double-wall nanotubes, flexoelectricity causes a straddling to staggered band gap transition.

Second derivative analysis of synthesized spectra for resolution and identification of overlapped absorption bands of amino acid residues in proteins: Bromelain and ficin spectra in the 240-320 nm range.

We establish the origin and formation of peaks in UV absorption spectra of proteins by applying the second derivative analysis to (i) spectra of the native protein, (ii) to its model spectra "synthesized" as a sum of partial free amino acid spectra and (iii) to absorption spectra of the free amino acids. We show that the bromelain peaks at 248.2, 253.

Influence of UV radiation on molecular structure and catalytic activity of free and immobilized bromelain, ficin and papain.

Our research has shown that the degree of photosensitivity of the cysteine proteases can be arranged in the following order: bromelain → ficin → papain. After the UV irradiation with 151 J·m intensity of a bromelain solution, the enzyme activity has increased. No decrease in the catalytic capacity and the change in the size of the molecule was recorded in the 151-6040 J·m range of irradiation intensities.

Immobilization of inulinase on KU-2 ion-exchange resin matrix.

We develop a technique for the sorption of inulinase from Kluyveromyces marxianus on the KU-2 matrix cation-exchanger. The most appropriate conditions for immobilization are: 25 °C, pH 4.5, incubation time 1.

Modulation of Structural and Functional Properties of Human Lymphocytes by Reactive Oxygen Species.

The effects of ROS on functional properties (cytotoxic activity, antibody-producing activity, TNFα synthesis, and free cytosol calcium level), membrane structure (by expression of some surface markers), and apoptosis of lymphocytic cells were estimated in the peripheral blood of healthy volunteers. O, [Formula: see text], OH, and HO mostly suppressed cytotoxic activity of lymphocytes against Ehrlich ascites carcinoma cells and inhibited IgG synthesis and expression of receptors and surface markers (Fc receptors, CD3, CD19, and CD56). The exposure of lymphocytes to HO (10 M), O, and OH was followed by an increase in the level of a secondary messenger, intracellular calcium, in comparison with non-exposed cells.

Carbon Monoxide (CO) Modulates Surface Architectonics and Energy Metabolism of Human Blood Erythrocytes.

Scanning electron microscopy study showed that exposure to CO for 60, 75, and 90 min induced heterogeneous changes in erythrocyte population. Increasing the duration of exposure of blood erythrocytes to CO was followed by the appearance of cells with morphological changes. The formation of discocytes with processes (≥1) was followed by the appearance of "deflated ball"-shaped erythrocytes.

Efficient fructose production from plant extracts by immobilized inulinases from Kluyveromyces marxianus and Helianthus tuberosus.

The enzymatic hydrolysis of poly- and oligosaccharides from plants seems like an advantageous approach for sugars production. Two inulinases producing fructose from plant oligosaccharides were isolated from yeast Kluyveromyces marxianus and plant Helianthus tuberosus. Both enzymes were immobilized on polymeric carriers by using the static adsorption approach.