Biochemistry (Moscow)最新文献

This review focuses on current challenges associated with the study and standardization of chitosan, a promising biopolymer for medical applications. Its key properties, such as biodegradability, low toxicity, mucoadhesion, and antimicrobial effects, make it highly sought in various fields of medicine. Particular attention is given to the analysis of chitosan parameters, including molecular weight, degree of deacetylation, and pattern of acetylation, as well as compliance with pharmacopoeial requirements. The challenges associated with the reproducibility of chitosan properties and the absence of uniform analytical standards are addressed. The review also summarized the data on the relationship between the chitosan structural characteristics and biological activity (antimicrobial, antioxidant, immunomodulatory, etc.), which is important for predicting its behavior in biological systems. Regulatory considerations governing the medical use of chitosan and prospects for its introduction into medical practice are examined. This review will be useful for researchers engaged in the development, characterization, and standardization of chitosan-based biomaterials.

Proteins that bind components of bacterial cell wall play a key role in innate immunity and interactions between bacteria and host organisms. They participate in the control of peptidoglycan synthesis and degradation, determine the pathogenic specificity of bacteria, affect their ability to adhere and invade, and serve as important elements of molecular recognition. The review discusses proteins of diverse origins and their recombinant analogues, their structure and binding mechanisms, and prospects for application in the diagnostics of bacterial infections and functionalization of nanomaterials.

The TPO gene belongs to the group of genes responsible for the biosynthesis of thyroid hormones and encodes thyroid peroxidase, a key enzyme involved in this process. Mutations in these genes can result in thyroid dysfunction characterized by reduced levels of thyroid hormones. Hypothyroidism caused by TPO pathogenic variants typically presents as permanent hypothyroidism and is frequently associated with endemic goiter. This analytical review summarizes and systematizes data from the studies conducted in different regions of the world on mutations identified in the TPO gene in patients with hypothyroidism. Particular attention is given to mutations within structural and functional domains of thyroid peroxidase, which has a unique molecular architecture within its family.

This article reviews biosynthesis of the valuable fat-soluble compounds with antioxidant activity, in particular vitamin E isomers and carotenoids, in yeast cells. Main genetic engineering approaches to increase microbial production of these substances are described. The main innovative strategies for subcellular separation of synthesis, storage, and recovery of lipophilic compounds are discussed, and examples of cell morphology engineering importance of are shown.

In recent years, reconstructive surgery strategies have been supplemented with innovative approaches aimed at developing tissue-engineered structures using autologous tissues and biodegradable scaffolds and matrices, the purpose of which is to reduce the risk of postoperative complications, on the one hand, while ensuring accelerated restoration of the structure and functions of organs, on the other hand. The review systematizes modern scientific trends in the field of tissue engineering of the urethra, focused on creation of biocompatible and functionally active tissue-engineered structures using achievements of cellular technologies and materials science. Particular attention is paid to describing the mechanisms and ways of forming a complete and functional three-dimensional structure of the urethra, including the use of organoids. It is expected that this strategy will contribute to the development of personalized therapeutic approaches and improved clinical outcomes in the patients with urological diseases.

Widespread interest and broad application of alginic acid and its salts in tissue engineering, regenerative medicine, biotechnology, and pharmaceutical industry is due to the several unique properties: biomechanical compatibility with living tissue, lack of toxicity, and bioabsorption capacity. This literature review analyzes effects of the anionic structure of the binary alginate copolymer on physicochemical properties of the resulting solutions and gels, as well as characteristics and conditions of their processing to obtain functional products for medical and biological applications. Dependence of functionality of the products on the ratio of M(β-D-mannuronate)/G(α-L-guluronate) blocks in the chain and on the source of alginate are also considered. Influence of the quantitative content of guluronic (G) acid blocks in the chain of linear alginate on its susceptibility to H⁺-induced gelation is described. A review of the mechanisms of gelling in the alginate solutions caused by formation of ionic, hydrogen, and covalent bonds is provided. In particular, attention is paid to the rate of dissolution of alginate salts, viscosity properties of the solutions based on them, and their dependence on ionic strength and pH. The mechanisms of interaction between both native and chemically modified alginates with various biologically active substances, drugs, and surfactants are considered. A detailed study of these processes opens new possibilities not only for obtaining dimensionally stable gels for tissue engineering structures, but also for obtaining systems designed for the controlled release of drugs.

Insulin exerts a complex effect on metabolism, cell growth, and differentiation interacting with its receptor. Adipose tissue is one of the key targets for insulin; in this tissue insulin regulates the processes of energy storage, as well as tissue renewal and emergence of new adipocytes. Insulin activates conversion of glucose into fatty acids, inhibits lipolysis, and induces adipogenic differentiation of adipose tissue stem cells. The insulin receptor is a classic tyrosine kinase receptor that activate phosphoinositide-3-kinase and mitogen-activated protein kinase signaling cascades. At the same time, insulin receptor activates several non-canonical signaling cascades that determine features of the receptor functioning. For example, insulin can affect phosphoinositide metabolism, as well as calcium and redox-dependent signaling. In addition, the insulin receptor can also interact with the trimeric G proteins-coupled receptors (GPCRs). Here, we review canonical and non-canonical signaling cascades activated by the insulin receptor and molecular mechanisms of their involvement in regulating the human adipose tissue renewal.

The Escherichia coli bacterial expression system was the first platform developed for recombinant protein production and remains the fastest, simplest, and most cost-effective system for achieving high protein yields for fundamental research, as well as biotechnological and pharmaceutical applications. Bacterial surface display systems and secretion of target proteins have become widely used approaches. These strategies help prevent intracellular aggregation and proteolytic degradation of recombinant proteins, enabling the recovery of soluble, properly folded, and stable protein products. In the case of toxic proteins, secretion mitigates their inhibitory effects on essential host cell processes. Furthermore, secretion of target proteins and peptides significantly simplifies their purification. The review summarizes the data on E. coli secretion systems with a special focus on protein export and display strategies, and discusses their applications in scientific research, industrial biotechnology, and medicine.

D-Amino acid oxidase (DAAO, EC 1.4.3.3) is a FAD-dependent enzyme that catalyzes the oxidative deamination of D-amino acids to produce the corresponding α-keto acids, hydrogen peroxide, and ammonium ion. High stereoselectivity toward D-enantiomers and favorable kinetic parameters make DAAO a convenient biocatalytic element for analytical applications. This review systematizes the main areas of DAAO use in bioanalysis, including clinical diagnostics, monitoring of food and biotechnological processes, and environmental surveillance. Sensor platforms and detection modes are discussed, including colorimetry, fluorimetry, chemiluminescence, electrochemistry, photoelectrochemistry, and oxygen-based detection methods. The review also addresses factors determining analytical suitability, strategies to broaden selectivity, as well as engineering approaches and structure-guided discovery of new DAAOs. Current limitations are highlighted and future prospects are outlined, such as improving enzyme stability, scaling up portable devices, and integrating biosensing with digital analytics and machine-learning algorithms.

Fluorescent proteins (FP) are widely used to visualize biological processes in living cells, including their use as genetically encoded markers for molecular and cellular research. However, their expression, even at the cellular level, could lead to some difficulties in interpreting molecular events due to protein–cell interactions. At the level of immunocompetent organisms, immune mechanisms could also take place, complicating the work with the cells expressing fluorescent proteins and interpretation of the experimental results. This led to the study of immunogenicity of FPs in the models of various diseases, in particular, cancer, and development of the models exhibiting immune tolerance to FP. This review describes various approaches for selecting disease models that are more immunotolerant to the expression of fluorescent proteins, and for reducing immunogenicity of both FP-expressing tumor models and some other diseases models. It highlights the ways to use the increased immunogenicity of the fluorescent tumors in experimental oncology, as well highlights some aspects of reducing immunogenicity of the fluorescent proteins exogenously administered to laboratory animals.