Moscow University Chemistry Bulletin最新文献

This article succinctly outlines the key points of the emergence and development of methods for chemical modification of the surface of inorganic substrates. It is shown that the assumption of the presence of chemically active functional groups on such surfaces arose relatively recently, although the first experience of practical application was carried out in the middle of the 19th century. The main stages in the development of the chemistry of surface compounds are traced.

This review is devoted to the consideration of pathological intracellular mechanisms characteristic of Huntington’s disease and the central role of huntingtin protein in these processes. The features of mutant huntingtin aggregates utilization by the ubiquitin–proteasome system and autophagy, as well as the possibilities of polyglutamine-containing substrates hydrolysis by proteasome are discussed.

Biopolymer materials based on natural collagen (gelatin, hydrolyzed collagen) are widely used in the food, pharmaceutical, and cosmetic industries due to their low toxicity, high biocompatibility, low antigenicity, and unique mechanical and technological properties. Hydrolyzed collagen, unlike gelatin, is formed by peptides with a lower molecular weight. Its advantages are higher bioavailability and biodegradability in comparison with gelatin. In this study, biopolymer matrices containing a dioxidine antibacterial drug are obtained based on hydrolyzed collagen using low-temperature technologies. It is shown that, varying synthesis parameters such as the concentration of hydrolyzed collagen in the precursor solution (from 1 to 10%), matrix crosslinking time (0.1–24 h), and cryoforming temperature (–30 and –196°C), it is possible to change the morphology and structure of the matrix, its degradation time, and drug release time. The composition and structure of dioxidine/hydrolyzed collagen systems are characterized by SEM and IR and UV spectroscopy. The antibacterial activity of the resulting dioxidine/hydrolyzed collagen systems against E. coli and S. aureus is characterized by the disk diffusion method.

The review is dedicated to the photochemical reactions of radical cations (RC) of various organic oxygen-containing compounds stabilized in low-temperature matrices. The nature of RC and the products of their photochemical reactions has been established via quantum chemistry, electron paramagnetic resonance (EPR) and low-temperature optical spectroscopy. Depending on the structure of the precursor molecule, various mechanisms of photoconversion arise for these RC: charge transfer to matrix molecules, hydrogen atom and proton transfer, isomerization, dissociation. This study allowed us to posit that there is no correlation between the structure of the molecule of the precursor molecule and the variety of available phototransformation channels for the corresponding RC in frozen matrices.

This review presents the data on the structure of bioluminescent systems of marine animals that use coelenterazine-dependent luciferases as light-emitting proteins. It is shown that these luciferases and their genetic variants with new useful properties are successfully used as reporter molecules in a variety of analytical systems in vitro and in vivo due to the availability, stability, and high quantum yield of the reactions. Their application ensures a high level of sensitivity, simple design, and fast analysis.

In today’s world, disease rates are increasing day after day because of environmental factors, lifestyles and technology. Although there are many drugs for many diseases, people’s interest and demand for herbal products are increasing. So, plants that can be used in the treatment of diseases have to be researched scientifically. Neuraminidase belongs to a class of glycosyl hydrolases that release terminal sialic acid from glycoproteins, glycolipids and polysaccharides. Neuraminidases could be found in animals, microorganisms and viruses. They have an impact on pathogenicity. This enzyme which is required for viral replication is a surface glycoprotein in influenza types A and B. In this study, we examined the inhibitory effects of some plant extracts and chemical compounds on neuraminidase activity. The result of our experiments indicates that the neuraminidase inhibitory activities of plant extracts and chemical compounds increased in a dose-dependent manner. We can conclude that the plant extracts and chemicals/drugs can be used in pharmaceutical industries and drug treatment due to their neuraminidase inhibitory activities.

In this study, an attempt is made to analyze the published data regarding the effectors of bacterial lysis in the presence of various bacteriolytic enzymes. Despite the differences between such enzymes, it is possible to identify certain general patterns of their action on a highly complex substrate—a living bacterial cell protected by a cell wall and additional complexes of biopolymers associated with it. Chicken and human lysozymes are the best known of these enzymes. They have some structural differences but are generally very similar in properties. Understanding the characteristics of the antibacterial action of bacteriolytic enzymes present both in medications and in the human immune system is extremely important for the development of new approaches to combat bacterial infections, including antibiotic-resistant ones. Moreover, certain logical and methodological approaches used to study bacteriolytic enzymes can be extremely useful for studying and describing other enzymes that affect complex polymer substrates in real biological situations.

A quantitative assessment of the expression of estrogen receptors alpha (ERα) is carried out in 115 samples of non-small cell lung cancer (NSCLC) by an immunofluorescent assay and flow cytometry. It is shown that a high level of ERα of ≥20% predicts a higher aggressiveness of NSCLC than at a low level of <20%: median survival based on a follow-up period of 78 months increases by 1.5 times; the risk of death is reduced by a factor of almost 2.0 (p = 0.04). The time to death increases on average by 18 months in about 20% of patients with a low ERα expression. The results validate the informative value of the immunofluorescence analysis and flow cytometry for quantifying the ERα expression and substantiate the prospects of antiestrogen therapy as a new option for NSCLC treatment, in particular, by analogy with breast cancer—in a long-term adjuvant therapy in ERα⁺ NSCLC patients.

A search for amino acid residues, whose replacement could contribute to the optimal maturation of the moxSAASoti fluorescent protein at 37°C, is carried out. For many other fluorescent proteins, this characteristic was improved by chance through many rounds of random mutagenesis; however, we managed to find two positions, 74 and 125, which clearly affect the process of moxSAASoti maturation, which is verified by introducing substitutions at these positions by site-directed and site-saturation mutagenesis.