卷 50, 编号 5 (2024)

Gelatins are formed during technological stages of processing animal connective tissue proteins (primarily – collagens) and, from a biochemical point of view, are represented as various polypeptide products. In most cases, gelatins as commercial products are 52.5% made from the skin and bones of cattle; 46.0% – from pig skin and only 1.5% – using other animals. At the beginning of the 21st century, the bulk of gelatins produced are used in food products, about a third in the medical sector, and only about 6% in technical or other industrial applications. Currently, trends towards a healthy lifestyle have intensified, which, along with the religious and cultural traditions of many countries, encourages scientists to look for sources of gelatins that are not related to mammals, but are close to them in physicochemical and functional characteristics. Therefore, recently there has been a tendency that the gigantic volume of production of gelatins from mammals (cattle and pigs) is beginning to decline, although not significantly so far, compared with the relative increase in the production of gelatins from by-products and waste from industrial poultry farming. Moreover, over the past decades, global poultry meat production has increased by more than a third. The optimal content of amino acids (AA) and their ratios in gelatins from cattle and pig skin for their further use is shown. Of course, the AA content in gelatins from pig and cattle skin obtained under different technological conditions may differ significantly. However, in general, these differences are not critical and therefore, sometimes gelatins are obtained from a mixture of animal waste. Recently, in Russia, a composition of protein ingredients from hydrolysates of pig and cattle skin with the addition of dried blood plasma was proposed, which had a significantly better AA composition than in traditional gelatins, which allowed the authors to assume increased biological and nutritional value of the developed product. In addition, a number of authors have discovered an improvement in a number of indicators and biological properties of gelatins from a mixture of animal waste with the formation of a number of specific peptides. Thus, new compositions based on known gelatins with an optimal AA composition are currently being actively developed, leading to improved nutritional and functional properties. The fundamental and applied significance of this review lies in a detailed description of the main studies on the amino acid composition of gelatins and identifying their relationship with the key biochemical and technological indicators of gelatin-based materials.

In recent years, significant progress has been achieved in the treatment of patients with colon cancer, but in most cases treatment is accompanied by the development of drug resistance. Recently discovered iron-dependent cell death, ferroptosis, makes it a promissing therapeutic target to reduce the recurrence rates. In this study we have examined the effect of 3-hydoxyquinazoline derivatives on ferroptosis induction in two colon cancer cells HCT-116 and DLD-1. The ferroptotic cell death was identified by the level of lipid peroxidation. The level of lipid peroxidation in HCT-116 cells induced by some compounds approached the activity of the reference drug erastin. This scenario changed significantly when the ferroptosis induction was studied in DLD-1 cells. Two 3-hydroxyquinazoline derivatives induced levels of lipid peroxidation in DLD-1 cells that exceeded those of erastin. The preliminary results obtained suggest that three new compounds can be considered as an antitumor agent for the treatment of colon cancer, and also indicate the prospects of further searching for ferroptosis inducers among 3-hydroxyquinazoline derivatives.

The development of controllable gene editing systems on the base of CRISPR/Cas is an actually problem of modern molecular biology and genetic enginery. Interesting variant of solution of this problem is modification of guide RNA by introduction of photocleavable linkers. We developed the approach to the synthesis of cyclic photocleavable guide crRNA for the CRISPR/Cas9 system with photolinker on the base of 1-(2-nitrophenyl)-1,2-ethanediol (PL). Upon irradiation by UV-light these guide RNA are linearized and CRISPR/Cas9 system is activated. Two chemical methods to the cyclization of RNA were tested: Michael reaction (thiol-maleimide condensation) and Cu-catalyzed azide-alkyne cycloaddition (CuAAC, click-chemistry reaction). For this purpose 5',3'-modified RNA containing reactive groups were prepared. The advantages of CuAAC reaction for cyclic RNA preparation was demonstrated. Effectivity of cyclic RNAs is depends from their secondary structure and ability of reactive groups to draw together. Series of photocleavable and control non-cleavable cyclic crRNA were obtained. It was shown that cyclic crRNAs guide nuclease Cas9 for plasmid cleavage less effective but linearization of photocleavable cyclic crRNA increases extent of plasmid cleavage. Developed approach permits prepare cyclic photocleavable RNA including spatiotemporal activation of guide RNA for gene editing. Photoregulation of gene editing will permit to lower the off-target effects and to carry out the editing more targeting.

The Lon protease family belongs to the key peptide hydrolases of the protein quality control (PQC) system, which plays a leading role in maintaining the integrity of the cellular proteome in all natural kingdoms. Moreover, Lon proteases are the only family of ATP-dependent proteases of PQC which comprises a number of structurally distinct subfamilies. Recently, it has been suggested that the Lon family contains a previously unclassified LonBA subfamily, which includes enzymes from bacteria of the Bacilli and Clostridia classes. Using bioinformatics analysis, data were obtained on the structural features of enzymes of the putative new subfamily and on the existence of two different groups of Lon proteases in this subfamily.

A method has been developed for obtaining active amino groups on the surface of a polyethylene terephthalate (PET) substrate. A method has been developed to quantify the concentration and distribution of chemically accessible amino groups on the surface of a PET substrate using the cyanine dye Cy5 and digital fluorescence microscopy. Amino groups can be used for further chemical modification of the PET surface, grafting of various functional groups and covalent binding with biomolecules, which opens up prospects for widespread use of inexpensive PET as functional substrates in biochips, biosensors, “laboratory-on-a-chip” devices and other biotechnological applications.

Identification of driver mutations in tumors is an extremely important task in oncology for the choice of treatment strategy and assessment of therapy efficacy. In many cases, especially in disease monitoring, there is a need to detect a small number of copies of the mutant allele against the background of excessive content of wild-type DNA. In this work we investigated the possibilities of highly sensitive detection of mutations in IDH1 and IDH2 genes at suppression of wild-type DNA amplification using oligomers of “locked” nucleic acid (LNA) with subsequent hybridization of fluorescently labeled polymerase chain reaction (PCR) product on a biological microchip (biochip). The limit of detection of mutant DNA is 0.1% in the wild-type DNA background. The effectiveness of this approach is demonstrated by analyzing 26 samples of chondroid tumors and glial brain tumors with low representation of the mutant allele, previously undetected mutations R132C, R132L and R132H were identified in three cases.