Application of Nucleic Acid Frameworks in the Construction of Nanostructures and Cascade Biocatalysts: Recent Progress and Perspective

Nucleic acids underlie the storage and retrieval of genetic information literally in all living organisms, and also provide us excellent materials for making artificial nanostructures and scaffolds for constructing multi-enzyme systems with outstanding performance in catalyzing various cascade reactions, due to their highly diverse and yet controllable structures, which are well determined by their sequences. The introduction of unnatural moieties into nucleic acids dramatically increased the diversity of sequences, structures, and properties of the nucleic acids, which undoubtedly expanded the toolbox for making nanomaterials and scaffolds of multi-enzyme systems. In this article, we first introduce the molecular structures and properties of nucleic acids and their unnatural derivatives. Then we summarized representative artificial nanomaterials made of nucleic acids, as well as their properties, functions, and application. We next review recent progress on constructing multi-enzyme systems with nucleic acid structures as scaffolds for cascade biocatalyst. Finally, we discuss the future direction of applying nucleic acid frameworks in the construction of nanomaterials and multi-enzyme molecular machines, with the potential contribution that unnatural nucleic acids may make to this field highlighted.

Evaluation of the Safety and Toxicity of the Original Copper Nanocomposite Based on Poly-N-vinylimidazole

A new original copper nanocomposite based on poly-N-vinylimidazole was synthesized and characterized by a complex of modern physicochemical and biological methods. The low cytotoxicity of the copper nanocomposite in relation to the cultured hepatocyte cells was found. The possibility to involve the copper from the nanocomposite in the functioning of the copper-dependent enzyme systems was evaluated during the incubation of the hepatocyte culture with this nanocomposite introduced to the nutrient medium. The synthesized new water-soluble copper-containing nanocomposite is promising for biotechnological and biomedical research as a new non-toxic hydrophilic preparation that is allowed to regulate the work of key enzymes involved in energy metabolism and antioxidant protection as well as potentially serving as an additional source of copper.

Particular Patterns of the Influence of the Physiology of Normal Pregnancy on the Pharmacokinetics of Drugs in the Liver

Pregnant women are the most "untouchable" group of people in relation to pharmacological research due to ethical and legal aspects, as well as concerns for the health and integrity of the fetus. And that is why pregnant women practically do not participate in clinical, pharmacodynamic, or pharmacokinetic testing. The mechanisms of teratogenesis are unpredictable, and in this case mutations can occur regardless of the duration of pregnancy and at any level. In women during pregnancy, the activity of liver enzyme systems involved in drug metabolism changes completely, which affects their clearance. This should be taken into account when selecting drugs and dosages for the treatment of various diseases. Our study showed that during pregnancy, a significant decrease in the intrinsic hepatic clearance of the CYP1A2 substrate is enhanced by a decrease in the binding of theophylline to plasma proteins and an increase in the glomerular filtration rate.

Interconnection of phospholipolysis and monooxygenase catalysis

A review of the main experimental results in the field of studying the interaction in vivo and in vitro of enzyme systems responsible for the metabolism of arachidonic acid is presented. Metabolic events from its release from phospholipids (phospholipase A2) to its transformation (cytochromes P450) into the most important intracellular messengers of external signal transmission to the internal “language of the cell” are discussed.

Enzyme systems involved in glucosinolate metabolism in Companilactobacillus farciminis KB1089

Cruciferous vegetables are rich sources of glucosinolates (GSLs). GSLs are degraded into isothiocyanates, which are potent anticarcinogens, by human gut bacteria. However, the mechanisms and enzymes involved in gut bacteria-mediated GSL metabolism are currently unclear. This study aimed to elucidate the enzymes involved in GSL metabolism in lactic acid bacteria, a type of gut bacteria. Companilactobacillus farciminis KB1089 was selected as a lactic acid bacteria strain model that metabolizes sinigrin, which is a GSL, into allylisothiocyanate. The sinigrin-metabolizing activity of this strain is induced under glucose-absent and sinigrin-present conditions. A quantitative comparative proteomic analysis was conducted and a total of 20 proteins that were specifically expressed in the induced cells were identified. Three candidate proteins, β-glucoside-specific IIB, IIC, IIA phosphotransferase system (PTS) components (CfPttS), 6-phospho-β-glucosidase (CfPbgS) and a hypothetical protein (CfNukS), were suspected to be involved in sinigrin-metabolism and were thus investigated further. We hypothesize a pathway for sinigrin degradation, wherein sinigrin is taken up and phosphorylated by CfPttS, and subsequently, the phosphorylated entity is degraded by CfPbgS. As expression of both pttS and pbgS genes clearly gave Escherichia coli host strain sinigrin converting activity, these genes were suggested to be responsible for sinigrin degradation. Furthermore, heterologous expression analysis using Lactococcus lactis suggested that CfPttS was important for sinigrin degradation and CfPbgS degraded phosphorylated sinigrin.

Overview of lignocellulolytic enzyme systems with special reference to valorization of lignocellulosic biomass

: Lignocellulosic biomass, one of the most valuable natural resources, is abundantly present on earth. Being a renewable feedstock, it harbors a great potential to be exploited as a raw material, to produce various value-added products. Lignocellulolytic microorganisms hold a unique position regarding the valorization of lignocellulosic biomass as they contain efficient enzyme systems capable of degrading this biomass. The ubiquitous nature of these microorganisms and their survival under extreme conditions have enabled their use as an effective producer of lignocellulolytic enzymes with improved biochemical features crucial to industrial bioconversion processes. These enzymes can prove to be an exquisite tool when it comes to the eco-friendly manufacturing of value-added products using waste material. This review focuses on highlighting the significance of lignocellulosic biomass, microbial sources of lignocellulolytic enzymes and their use in the formation of useful products.

Indicators of lipid peroxidation and the activity of antioxidant system enzymes as predictors of the development of metabolic disorders in primary obesity

Aim. To assess the effectiveness of indicators of lipid peroxidation and the activity of antioxidant system enzymes in the early diagnosis of metabolic disorders. Methods. The study included 269 women of fertile age with primary obesity. The control group consisted of 35 women. The clinical examination included identification of the type of obesity, whole-body fat percentage, the level of glycemia and the index of insulin resistance, biochemical markers of lipids, hormones (leptin and insulin), malondialdehyde and enzyme activity (peroxidase and catalase). The statistical significance of the differences was determined by using the inversion test. Spearman's rank correlation coefficient was used to assess the degree of relationship between quantitative characteristics, and scatter diagrams were used to compare two variables (Statistica software version 10.0). Results. A statistically significant increase in basal and stimulated immunoreactive insulin was found in obese patients compared with the controls (p 0.01). Stimulated immunoreactive insulin levels, insulin resistance score (HOMA-IR) and the level of leptin in the group of patients with android obesity was higher than in the group with gynoid obesity (p 0.01). The relationship between the concentration of serum malondialdehyde and whole-body fat percentage was found to be more significant (r=0.412; p 0.001) than the relationship with the type of obesity (r=0.257; p 0.01). Positive correlations were found between serum malondialdehyde and insulin (r=0.35; p 0.001) and leptin (r=0.32; p 0.001) levels. The relationship between the concentration of serum malondialdehyde and the activity of enzyme systems was also noted. The activity of lipid peroxidation was higher in the group of patients with android obesity (malondialdehyde 3.3 mol/L) compared with the group of patients with gynoid obesity. In the same group, a higher activity of enzyme systems was noted. Conclusion. An increase in the concentration of serum malondialdehyde and the activity of enzyme systems should be considered as indicators of a high risk of developing metabolic syndrome.

Changes in the metabolism of innate immune cells of homoithermic animals infected with dormant forms of Yersinia pseudotuberculosis

Under the influence of unfavorable environmental factors, microorganisms pass into a viable, but uncultivated state and form a dormant (dormant) cellular phenotype, characterized by a lack of growth and metabolic activity. Dormant forms of bacteria are not detected by traditional microbiological methods, but they play an important role in the development of protracted and chronic infections in animals and humans. Purpose of the study: to characterize the experimental infectious process in warm-blooded animals, induced by the dormant phenotypes of Y. pseudotuberculosis, and to evaluate changes in the activity of the enzyme systems of inflammatory effector cells. For the study, bacteria were taken from a culture stored under static conditions for 10 years in a test tube under a layer of petroleum jelly at a temperature of 4–6 °C. Ultrastructural features of dormant cell forms were confirmed by transmission electron microscopy. The viability of dormant cells was assessed by the molecular genetic method (PCR). The absence of reproductive activity of the dormant phenotypes of Y. pseudotuberculosis was checked by repeated inoculations in LB broth, Endo and Serov›s media, and incubation at temperatures of 4–6, 22–24 and 37 °C. Further, the activity of the enzyme systems of cells of the inflammatory process effectors in vivo was investigated. During the experimental infection, the animals showed a gradual increase in the number of inflammatory effector cells. The prevailing number of neutrophils (65–70 %) on days 14–21 of infection indicated a developing inflammatory process. Reversion of the dormant form of Y. pseudotuberculosis in vivo and the development of an inflammatory process in the cells of the peritoneal exudate of infected animals inhibits the activity of the oxygen- and nitroxide-dependent bactericidal systems, as evidenced by the low values of lactate dehydrogenase, myeloperoxidase and nitric oxide. Thus, the data obtained indicate the possibility of reversion of the dormant forms of Y. pseudotuberculosis into vegetative forms 21 days after infection. On the part of the cells of innate immunity, modulation of the activity of intracellular enzymes, aimed at the induction of antimicrobial protection, was revealed.