Biophysics最新文献

{"title":"The Effect of Molixan, a Disulfide-Containing Immunomodulator, on Na+ Transport across Frog Skin Epithelium","authors":"A. V. Melnitskaya,&nbsp;Z. I. Krutetskaya,&nbsp;V. G. Antonov,&nbsp;N. I. Krutetskaya","doi":"10.1134/S0006350923050172","DOIUrl":"10.1134/S0006350923050172","url":null,"abstract":"<p>The effect of the pharmacological analogue of oxidized glutathione, disulfide-containing immunomodulator molixan, on the Na⁺ transport in the frog skin epithelium was studied. Using the voltage-clamp method, it was shown for the first time that molixan modulated Na⁺ transport in the frog skin epithelium. It was found that the application of molixan from the apical surface of the skin suppressed Na⁺ transport, whereas when added from the basolateral surface, molixan mimicked the action of insulin and stimulated Na⁺ transport. The results indicate that oxidized glutathione and its pharmacological analogues molixan and glutoxim unidirectionally modulate Na⁺ transport in frog skin.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 5","pages":"779 - 782"},"PeriodicalIF":4.033,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140073133","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":"Low Activity Forms of Cellulosolitic Microorganisms in Archaeological Contexts","authors":"L. N. Plekhanova,&nbsp;S. N. Udaltsov,&nbsp;A. S. Syrovatko,&nbsp;N. N. Kashirskaya","doi":"10.1134/S0006350923050214","DOIUrl":"10.1134/S0006350923050214","url":null,"abstract":"<p>The results of the study of low-activity forms of cellulolytic microorganisms in the soils of archaeological sites are presented. The objects of the study were soils with traces of wooden structures in the burials of Vyatichi (12th century). To date, traces of wood do not appear at the macro level. The data we obtained are compared with the results of a laboratory experiment to determine the rates of decomposition of cellulose in soils from various archaeological contexts. Cellulolytic activity was determined by the application method. It was shown that the cellulase activity of soils with traces of funerary wooden structures is 20% of the level of modern soils. This suggests the awakening or presence of living low activity forms of microorganisms that have been preserved in the soil for 800 years.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 5","pages":"823 - 830"},"PeriodicalIF":4.033,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140071727","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 Comparative Cytotoxic Activities of Lutein and Cisplatin in Combination with Liposomes in Relation to Breast Tumor Cells Exposed to Radiotherapy","authors":"R. A. Lafta,&nbsp;M. W. Shafaa,&nbsp;W. M. Darwish,&nbsp;M. S. El-Nagdy","doi":"10.1134/S0006350923050135","DOIUrl":"10.1134/S0006350923050135","url":null,"abstract":"<p>The interactions of the antitumor substance cisplatin and the antioxidant substance lutein with liposomes, which are considered as model membranes, have been characterized. The morphology of all liposomes was almost spherical; in the absence of the studied substances, liposomes were more evenly distributed by size and less prone to aggregation. The average size of unloaded liposomes was 617.90 ± 75.64 nm; after inclusion of cisplatin, lutein and their combination, it was 425.60 ± 64.74 nm, 877.85 ± 93.90 nm, and 189.91 ± 136.84 nm, respectively. The inclusion of cisplatin or lutein into liposomal membranes caused an increase in the zeta potential. In the presence of cisplatin in combination with lutein, the zeta potential reached the lowest values. The inclusion of cisplatin into liposomes led to a shift of the main melting point peak towards higher temperature compared to unloaded liposomes, which indicated a conformational violation of the structure of phospholipids. The addition of lutein caused the disappearance of the main endothermic peak characteristic of pure liposomes. A study by Fourier-transform infrared spectroscopy confirmed the interaction of lutein and cisplatin with functional groups of liposomes. In the absence of gamma irradiation, the <i>IC</i>₅₀ of lutein in the cytotoxicity test with MCF-7 cells was 10.62 μg/mL; the <i>IC</i>₅₀ of cisplatin was 41.02 μg/mL. The <i>IC</i>₅₀ of lutein and cisplatin in nanoliposomes was 65.84 and 34.29 μg/mL, respectively. In combination therapy with a dose of gamma radiation of 5 and 10 Gy, the <i>IC</i>₅₀ of lutein decreased from 17.0 to 9.5 μg/mL. The <i>IC</i>₅₀ of cisplatin changed from 51.00 to 43.09 μg/mL. This study showed that the cytotoxic effect of the standard form of lutein was stronger than that of lutein in nanoliposomes. According to this, a new therapy protocol can be proposed in which cisplatin should be replaced with lutein to increase the effectiveness of therapy against MCF-7 tumor cells.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 5","pages":"808 - 822"},"PeriodicalIF":4.033,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140073128","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":"Bioluminescence of Ctenophore Pleurobrachia pileus (O. F. Müller, 1776) in the Summer Period","authors":"A. V. Temnykh,&nbsp;M. I. Silakov,&nbsp;O. V. Mashukova","doi":"10.1134/S000635092304022X","DOIUrl":"10.1134/S000635092304022X","url":null,"abstract":"<p>The ability to bioluminescence has been found in many marine hydrobionts, including almost all representatives of the Ctenophora phylum which have the ability to emit light. The luminescence of species and bioluminescent substrates isolated from them are actively used in biology, ecology and medicine to study the physiological state of the organism or to identify unfavorable environmental parameters. Parameters of luminescence of representatives of Black Sea ctenophores <i>Mnemiopsis leidyi</i> A. Agassiz, 1865 (Lobata) and <i>Beroe ovata</i> Bruguière, 1789 (Beroida) are used in the study of the effects of toxicants, such as liquid hydrocarbons, polychlorinated biphenyls, and heavy metals. The ability to bioluminescence of an autochthonous inhabitant of the Black Sea, the ctenophore <i>Pleurobrachia pileus</i> (O.F. Müller, 1776), was doubted by some researchers. The aim of this study was to confirm the ability of this species to glow and to choose the optimal time for conducting experiments with it. It was found that all size groups of this species exhibited a bioluminescent reaction to mechanical and chemical stimulation at any time of the day. With chemical stimulation, the bioluminescent signal energy values were several times higher than with mechanical stimulation. It was found that the optimal time for conducting biophysical studies is the period from 20:00 to 6:00, since the energy indicators of the bioluminescent signal at this time are maximum within a day.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"596 - 606"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138629183","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":"Mechanism of Inhibition of the Oxygen-Evolving Complex of Photosystem II by Lanthanide Cations","authors":"E. R. Lovyagina,&nbsp;A. V. Loktyushkin,&nbsp;N. S. Vasiliev,&nbsp;B. K. Semin","doi":"10.1134/S0006350923040103","DOIUrl":"10.1134/S0006350923040103","url":null,"abstract":"<p>The interaction of La³⁺ and Tb³⁺ cations with the Ca-binding site of the oxygen-evolving complex of photosystem II samples depleted of calcium has been studied. The binding of cations to the Ca-binding site is irreversible and the bound cations cannot be washed out or replaced by Ca²⁺ cations. The feature of lanthanides to bind strongly to the Ca-binding site was used to investigate whether the bound Ln³⁺ cation has an effect on the high-affinity Mn-binding site of the oxygen-evolving complex. For this purpose, hydroquinone was used to extract manganese cations from the oxygen-evolving complex of the calcium-depleted photosystem II membranes with the Ca-binding site blocked by La³⁺ or Tb³⁺, and the activity of the high-affinity site was then examined using exogenous electron donors (Mn²⁺ + H₂O₂) and 1,5-diphenylcarbazide. It was found that lanthanide cations bound to the Ca-binding site significantly inhibited oxidation of electron donors through the high-affinity Mn-binding site. The mechanism of the observed effect is discussed.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"519 - 524"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138629010","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":"Comparative Analysis of Interchannel Relationships on Electroencephalograms in Healthy People and Patients with Depression Using the Method of Correlation Ratios","authors":"M. E. Sobolev,&nbsp;A. L. Gorelik,&nbsp;O. L. Vlasova","doi":"10.1134/S000635092304019X","DOIUrl":"10.1134/S000635092304019X","url":null,"abstract":"<p>During the study of patients with depression, an approach was applied to the clinical material based on the analysis of the interrelationships of electroencephalogram channels using correlation ratios capable of objectively assessing the properties of relationships in any of their models (linear and nonlinear). The possibility of analyzing paired relationships with the determination of parameters that differ for norm and pathology was shown based on the constructed correlation ratio matrices. The directionality of the relationships between the leads was also found. The most significant differences, in our opinion, were differences in interhemispheric occipital relationships. This approach can become the basis for determining unique quantitative markers of both depressive states and other neuropsychiatric disorders.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"643 - 652"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138629301","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":"Structure of an Ice-Binding Protein from Myoxocephalus octodecemspinosus Determined by Molecular Dynamics and Based on Circular Dichroism Spectra","authors":"G. A. Oleinik,&nbsp;P. Zhdanova,&nbsp;V. V. Koval,&nbsp;A. A. Chernonosov,&nbsp;S.V. Baranova","doi":"10.1134/S0006350923040152","DOIUrl":"10.1134/S0006350923040152","url":null,"abstract":"<p>The production of proteins capable of binding ice is one of the strategies evolved in biological organisms for survival in cold ecosystems where there is a risk of freezing. These proteins have an important ability to bind to the surface of ice, influence its growth and prevent cell damage and death. To understand the nature of interaction of such proteins with ice, it is necessary to know their structure. This study contributes to the understanding of the structural and dynamic mechanisms of action of ice-binding proteins that ensure the adaptation of organisms in critical conditions. The study of the contribution of proteins capable of binding ice to adaptation to cold conditions opens up wide opportunities in solving a number of important medical problems, including the development of effective cellular and organ cryoprotectants, as well as long-term storage of food products without loss of their consumer properties in the food industry.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"513 - 518"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352661","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 Effect of the Antioxidant System “Resveratrol – Iron Sulfonitrosyl Complex Sodium-μ2-Dithiosulphate-Tetranitrosyl Diferrate Tetrahydrate” on the Mitochondria of Pea Germ Epicotyls in vitro","authors":"N. Yu. Gerasimov,&nbsp;O. V. Nevrova,&nbsp;I. V. Zhigacheva,&nbsp;I. P. Generozova,&nbsp;A. N. Goloshchapov","doi":"10.1134/S0006350923040048","DOIUrl":"10.1134/S0006350923040048","url":null,"abstract":"<p>The interaction of antioxidants, plant polyphenol resveratrol and nitric oxide donor, sulfur nitrosyl iron complex with thiosulfate Na₂[Fe₂(S₂O₃)₂(NO)₄]₂ · 4H₂O (TNIC-thio), and their combined action on the mitochondria of epicotyls of pea seedlings in vitro were studied. The antioxidant activity of resveratrol at a concentration of 10^–6 M partially compensated for the toxic effect of TNIC-thio at high concentrations, which was most likely due to the manifestation of the pro-oxidant properties of high concentrations of the nitric oxide donor. The effect of resveratrol at concentrations of 10^–6 and 10^–8 M on the membranes of mitochondria isolated from the epicotyls of pea seedlings in the presence of 10^–8 M TNIC-thio led to a violation of the regulation system of lipid peroxidation of membranes, which caused antioxidant stress. The effect of resveratrol at a dose of 2 × 10^–5 M was of a dual nature and practically did not affect the structural state of mitochondrial membranes.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"525 - 530"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352558","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":"Influence of the Microenvironment Dynamics of Tryptophan on Its Fluorescence Parameters at Different Temperatures","authors":"V. V. Gorokhov,&nbsp;P. P. Knox,&nbsp;B. N. Korvatovsky,&nbsp;S. N. Goryachev,&nbsp;V. Z. Paschenko,&nbsp;A. B. Rubin","doi":"10.1134/S0006350923040061","DOIUrl":"10.1134/S0006350923040061","url":null,"abstract":"<p>The temperature dependences of the fast and slow fluorescence decay components of aqueous tryptophan solution after freezing under actinic light and in the dark were investigated in the temperature range from –170 to 20°C. A model of the direct and reverse electronic transitions from the excited state to the ground state and to the state with charge transfer in a tryptophan molecule was used to perform quantitative analysis. Three main spectral regions of tryptophan fluorescence were shown; they differed in the behavior of the temperature dependences depicted for the rates of transition from the excited state of tryptophan to the state with charge transfer. It was shown that the dynamics of the hydrogen bond system plays a key role in this transition. The system of hydrogen bonding determines the nonlinear nature of tryptophan fluorescence in the selected spectral regions. The non-linear behavior of the fluorescence lifetime and fluorescence spectra with temperature change is determined by the character of interaction of tryptophan with water and ice. It was shown that temperature rearrangements play a critical role in hydrogen bonding structure of H₂O that surrounds a tryptophan molecule in the excited state.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"503 - 512"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138629194","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":"Age-Related Peculiarities of the Effect of Stimulation of α2-Adrenergic Receptors on the Electrical Activity of Rat Cardiomyocytes","authors":"A. M. Galieva,&nbsp;N. I. Ziyatdinova,&nbsp;N. Mansour,&nbsp;L. I. Fashutdinov,&nbsp;T. L. Zefirov","doi":"10.1134/S0006350923040036","DOIUrl":"10.1134/S0006350923040036","url":null,"abstract":"<p>The effect of clonidine hydrochloride (an agonist of α2-adrenergic receptors) on the parameters of electrical activity of the atrial myocardium during pacing was studied. Clonidine hydrochloride in working cardiomyocytes with pacing causes a decrease in the action potential duration at the level of 50 and 90% in adult rats. In 1- and 3-week-old rats, this agonist causes an increase in the action potential duration at the level of 50 and 90%.</p>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"68 4","pages":"586 - 590"},"PeriodicalIF":4.033,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352152","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}