Biophysics最新文献

{"title":"Magnetic Biological Effect: Quantum Constraints","authors":"V. N. Binhi","doi":"10.1134/S0006350925700411","DOIUrl":"10.1134/S0006350925700411","url":null,"abstract":"<div><p>The spin-chemical mechanism of radical pairs is considered today as the most probable molecular mechanism explaining the observed biological effects of weak magnetic fields. The magnitude of these effects depends on the spin relaxation rate, but no explicit functional dependence has been proposed. In this paper, an analytical solution of the Liouville–Neumann equation for a system of two electrons and a nucleus is found, taking into account spin relaxation and chemical kinetics. A relationship is obtained that relates the magnitude of the magnetic effect to the rate of relaxation due to thermal disturbances. The effect obeys a general quantum constraint. At plausible relaxation rates, the calculated effects are small and cannot explain the observations. It can be concluded that today, despite the attractiveness of the radical pair mechanism and the increased theoretical understanding, the problem of magnetobiology still does not have a conceptual solution free from contradictions.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"353 - 360"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Macromolecular Crowding in Erythrocyte Cytoplasm","authors":"O. V. Slatinskaya,&nbsp;E. Yu. Parshina,&nbsp;A. I. Yusipovich,&nbsp;N. A. Brazhe,&nbsp;A. B. Rubin,&nbsp;G. V. Maksimov","doi":"10.1134/S0006350925700332","DOIUrl":"10.1134/S0006350925700332","url":null,"abstract":"<div><p>Using Raman spectroscopy, fluorescence spectroscopy, and time-correlated photon counting, it was found that an increase in the temperature of the human erythrocyte incubation medium causes an increase in the homogeneity of hemoglobin distribution in the cytoplasm of erythrocytes and a decrease in the packing density of the globin molecule, which is most likely the result of the effect of “macromolecular crowding” of the cell. The revealed conformational changes are characteristic only of hemoglobin in the cell and do not depend on changes in the surface potential of the plasma membrane. It is assumed that there are several pools of hemoglobin molecules that differ in the structure and dynamics of the protein globule, forming a heterogeneous distribution of hemoglobin inside the erythrocyte due to the combining of hemoglobin molecules into clusters. The possibility of the involvement of these effects in the signaling and regulatory function of oxygen transport and transport is discussed.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"277 - 284"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Purinergic Modulation of Ocular Muscle Contraction","authors":"S. N. Grishin,&nbsp;A. N. Gorshunova,&nbsp;A. Yu. Teplov,&nbsp;A. S. Grishin,&nbsp;A. R. Nasybullin,&nbsp;A. E. Khairullin","doi":"10.1134/S0006350925700381","DOIUrl":"10.1134/S0006350925700381","url":null,"abstract":"<div><p>The problem of purinergic regulation in synapses of phasic and tonic muscles of warm-blooded animals has been investigated. For this purpose, the effect of the cotransmitter of the main mediator, ATP, and its persistent metabolite, adenosine, on the contraction of various oculomotor systems of the rat, the lateral rectus (tonic) and circular (phasic) muscles of the eye, has been evaluated. ATP potentiated the carbacholine-evoked contraction of the rat lateral rectus muscle by one-quarter, while this purine, on the contrary, significantly inhibited the carbacholine-evoked contraction of the circular eye muscle. No significant manifestation of the modulatory effect of adenosine on the carbacholine-evoked contraction of the muscles under study was revealed. These results indicate a multidirectional postsynaptic effect of ATP on phasic and tonic oculomotor systems.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"320 - 323"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Photoprotective Properties of Chitosan and Chitosan Succinate against Trypsin for Different Methods of Enzyme Immobilization on Their Matrix","authors":"S. M. Pankova,&nbsp;M. G. Holyavka,&nbsp;M. S. Kondratyev,&nbsp;A. N. Lukin,&nbsp;V. G. Artyukhov","doi":"10.1134/S0006350925700289","DOIUrl":"10.1134/S0006350925700289","url":null,"abstract":"<div><p>UV irradiation at doses of 3020, 4510, and 6040 J/m² was found to decrease the level of specific activity of free trypsin by 28, 32, and 49%, respectively. Adsorption immobilization on the matrix of chitosans with molecular weights of 200 and 350 kDa, entrapment in chitosan (&lt;100 kDa) and chitosan succinate gel contribute to the preservation of trypsin molecule activity at the level of ~90% and higher. Under UV irradiation in the dose range of up to 6040 J/m² in the presence of a photosensitizer, methylene blue, at a concentration of 10^–4 mol/L the activity of free trypsin decreased by 72%. After immobilization, the stability of the enzyme complex under the above conditions increased: the activity of trypsin immobilized on the matrix of chitosans with molecular weights of 200 and 300 kDa was maintained at the level of about 75%, after entrapment of the enzyme in the chitosan gel (&lt;100 kDa), by up to ~50%, and chitosan succinate, by up to ~70%. The molecular docking method revealed that a number of tryptophan, tyrosine, and phenylalanine residues, as well as two cystines, take part in the formation of bonds and interactions between the trypsin molecule and the matrices of chitosan and chitosan succinate, which probably determines the photoprotective properties of these polysaccharides. IR spectroscopy showed that after UV irradiation in the presence of methylene blue and without it, no significant changes in the wave number values in the region of the amide I, II, and III bands were detected in the spectra of trypsin immobilized on chitosan and chitosan succinate matrices, which indicates that the stability of the enzyme structure in the complexes with these polysaccharides is maintained.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"226 - 238"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Octacalcium Phosphate Doped with Barium Cations for Application in Tissue Engineering","authors":"I. V. Smirnov,&nbsp;P. V. Smirnova,&nbsp;A. Yu. Teterina,&nbsp;V. V. Minaichev,&nbsp;M. I. Kobyakova,&nbsp;P. S. Salynkin,&nbsp;A. I. Zvyagina,&nbsp;K. V. Pyatina,&nbsp;E. I. Meshcheryakova,&nbsp;I. S. Fadeeva,&nbsp;S. M. Barinov,&nbsp;V. S. Komlev","doi":"10.1134/S0006350925700368","DOIUrl":"10.1134/S0006350925700368","url":null,"abstract":"<div><p>The effect of barium cation doping of octacalcium phosphate powder obtained using a low-temperature method on its phase and structural characteristics, as well as biocompatibility, including under in vitro conditions simulating inflammation, has been studied. It was found that doping with Ba²⁺ cations in the concentration range used (1, 5, and 10 calculated%) does not interfere with the low-temperature chemical transformation of dicalcium phosphate dihydrate and its conversion to octacalcium phosphate; however, the actual substitution is at a maximum of 6.7 at %. The results of in vitro studies show that the replacement of calcium ions with barium ions in the structure of octacalcium phosphate does not lead to an increase in cytotoxic properties; all studied variants of low-temperature octacalcium phosphate and its barium-substituted forms at the recommended concentration of 1 mg/mL do not exhibit toxic effects and are biocompatible. The effects identified for octacalcium phosphate with a maximum degree of Ca²⁺ substitution by Ba²⁺ equal to 10%, namely the absence of an effect on the content of lysosomes and reactive oxygen species in human macrophages under normal conditions and a significant decrease in the production of reactive oxygen species under conditions simulating inflammation, as well as a significant increase in the constitutive activation of T-lymphocytes in vitro, indicate that these processes are directly and dose-dependently associated with Ba²⁺ cations in the composition of octacalcium phosphate. Thus, the proposed method of low-temperature chemical transformation of Ba²⁺-substituted variants of octacalcium phosphate is promising and is of interest for obtaining materials based on calcium phosphate compounds with immunoregulatory properties. The obtained Ba²⁺-substituted variants of octacalcium phosphate are safe and biocompatible, while octacalcium phosphate with the maximum degree of Ca²⁺ substitution by Ba²⁺ is not only bioactive, but also has potential antioxidant and immunomodulatory effects.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"302 - 313"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Smoking on the State of the Thiol Disulphide System in Blood Plasma and the Frequency of TCR-Mutant Lymphocytes in Healthy Individuals and Cancer Patients","authors":"G. F. Ivanenko,&nbsp;I. A. Zamulaeva","doi":"10.1134/S0006350925700435","DOIUrl":"10.1134/S0006350925700435","url":null,"abstract":"<div><p>A comparative study of indicators of somatic mutagenesis and the thiol disulfide system in the peripheral blood of cancer patients before treatment and healthy individuals with different smoking status (<i>n</i> = 95) has been carried out. All studied parameters including the content of reduced (GSH) and oxidized (GSSG) glutathione and their ratio (GSH/GSSG), the frequency of lymphocytes with mutations at the T-cell receptor (TCR) locus were found to be significantly increased by 1.5–2.7 times in the general group of patients compared to those in the general group of healthy individuals (<i>p</i> &lt; 0.01 in all cases). After cessation of smoking, a decrease in the frequency of mutant cells and the ratio of reduced and oxidized glutathione was observed in patients (<i>p</i> &lt; 0.05). At the individual level, strong correlations were found between the frequency of TCR-mutant cells and the contents of GSH and GSSG only in the subgroup of smoking patients with a high level of mutagenesis. The correlation coefficient between the frequency of TCR-mutant lymphocytes and the GSH content in this subgroup was 0.82 (<i>p</i> &lt; 0.001) and for GSSG <i>r</i> = 0.68 (<i>p</i> &lt; 0.01). The results we obtained indicate the contribution of the thiol disulfide system to the formation of a high frequency of gene mutations in smokers with cancer.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"366 - 377"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum-Chemical Modelling of Adenosine Triphosphate Hydrolysis in Water Medium","authors":"G. N. Mukseev,&nbsp;A. N. Tikhonov","doi":"10.1134/S0006350925700253","DOIUrl":"10.1134/S0006350925700253","url":null,"abstract":"<div><p>The hydrolysis of adenosine triphosphate to adenosine diphosphate and orthophosphate was simulated using the density functional method. Two systems were considered: an adenosine triphosphate molecule in an aqueous solution and reaction products (adenosine diphosphate, orthophosphate, and H⁺) uniformly surrounded by water (<span>({{n}_{{{{{text{H}}}_{{text{2}}}}{text{O}}}}})</span> = 80). Calculations have shown that the hydrolysis of adenosine triphosphate is accompanied by a decrease in the total energy of the system, which is consistent with the ideas of the energy-donor nature of the reaction of hydrolysis of adenosine triphosphate to adenosine diphosphate and orthophosphate. In the absence of divalent cations, the decrease in energy as a result of adenosine triphosphate hydrolysis is Δ<i>E</i> = <i>E</i>_ADP+Pi − <i>E</i>_ATP ≈ −110 kJ/mol. Electrostatic interactions due to the presence of divalent cations (Mg²⁺ or Ca²⁺) increase the energy of hydrolysis (Δ<i>E</i> ≈ −135 kJ/mol). The results obtained are discussed in the context of the energy role of adenosine triphosphate in biological systems.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"189 - 199"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring LINE-1 Activity and the ATP Level in Human Cell Cultures","authors":"E. V. Kanov,&nbsp;O. M. Semenov,&nbsp;Yu. A. Gnennaya,&nbsp;D. N. Razgulyaeva,&nbsp;V. V. Gursky","doi":"10.1134/S0006350925700356","DOIUrl":"10.1134/S0006350925700356","url":null,"abstract":"<div><p>DNA demethylation makes closed regions of the genome available for transcription and thus causes increased activity of mobile genetic elements (transposons) in the genome. The study of the influence of abnormal activity of transposons on cell energy attracts attention due to the potential possibility of using this effect to create an energy deficit with subsequent launch of cell death programs, which may be relevant for the development of anti-cancer strategies. This paper presents the results of experimental measurements of the ATP level in HEK-293 cells obtained from human embryonic kidneys and the MCF-7 breast cancer cell line under normal and demethylation conditions. The HEK-293 line was transfected with a plasmid containing the LINE-1-EGFP genetic construct, and active insertion of the LINE-1 transposon in the transfected cells was shown. Transposon expression in demethylated MCF-7 cells was shown using real-time PCR. The results of ATP measurements demonstrate an increase in energy stores in cells upon both demethylation and transfection with LINE-1-EGFP. The observed effect suggests that the energy load expected from transposon activation is overwhelmed by the energy release from other cellular processes that occur during demethylation and transfection.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"297 - 301"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the Structure and Peroxidase Activity of Cytochrome C in Its Interaction with Phosphatidic Acid","authors":"V. V. Volkov,&nbsp;S. P. Konyukhova,&nbsp;A. V. Blagova,&nbsp;G. O. Stepanov,&nbsp;Yu. A. Vladimirov,&nbsp;A. N. Osipov","doi":"10.1134/S0006350925700319","DOIUrl":"10.1134/S0006350925700319","url":null,"abstract":"<div><p>A comparative study of the properties of cytochrome <i>c</i> in its interaction with phosphatidic acid is carried out. Similar conformational changes in the active center of cytochrome <i>c</i> occurring during its interaction with both cardiolipin and phosphatidic acid are demonstrated using the methods of spectrofluorometry. The presence of similar magnitudes of peroxidase activity of cytochrome <i>c</i> in its interaction with both cardiolipin and phosphatidic acid was corroborated by luminol-dependent chemiluminescence, and the use of the EPR method enabled the detection formation of phenoxyl radical of etoposide in both complexes. It can be concluded that both phosphatidic acid and cardiolipin effectively alter the structure of the active center of cytochrome <i>c</i> and contribute to the enhancement of its peroxidase activity. The obtained results may indicate a very probable participation of both cardiolipin and phosphatidic acid in the development of cytochrome <i>c</i>–mediated proapoptotic processes in mitochondria.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 2","pages":"259 - 267"},"PeriodicalIF":4.033,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The 3VmrMLM Method Provides New Genomic Variants Associated with Fiber Characteristics in Flax","authors":"M. A. Duk,&nbsp;A. A. Kanapin,&nbsp;M. P. Bankin,&nbsp;M. G. Samsonova","doi":"10.1134/S0006350925700186","DOIUrl":"10.1134/S0006350925700186","url":null,"abstract":"<div><p>Flax is an important agricultural crop grown for oil and fiber. Flax fiber is used in various industries and breeding new flax varieties with better fiber characteristics is subject of interest. Genome-wide association studies (GWAS) can find variants associated with traits important for fiber quality, but differences in data due to different growing conditions in different years reduce the power of GWAS methods. The 3VmrMLM method allows one to search for variants in data measured in several environments, allowing one to find new variants not found by other methods. Measurements in different years were taken as different environments; the method found a total of 205 variants characteristic of all or several environments, 37 of which were located in the body of known genes with important functions; the effect of some variants on fiber characteristics was also confirmed in an independent set of plants.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 1","pages":"136 - 145"},"PeriodicalIF":4.033,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145165884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}