Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology最新文献

{"title":"Effect of Methyltriclosan on the Functioning of Isolated Rat Liver Mitochondria and Permeability of Liposomal Membranes","authors":"K. S. Tenkov,&nbsp;M. V. Dubinin,&nbsp;A. A. Semenova,&nbsp;K. N. Belosludtsev","doi":"10.1134/S1990747821020082","DOIUrl":"10.1134/S1990747821020082","url":null,"abstract":"<p>Effects of methyltriclosan, a biodegradation product of the antimicrobial agent triclosan, on the functional parameters of rat liver mitochondria were studied. It was found that methyltriclosan inhibits the activity of complexes II and IV of the respiratory chain. This causes a decrease in the rate of oxygen consumption by mitochondria in states 3 and 3U_DNP. Methyltriclosan was shown to increase the rate of hydrogen peroxide production by rat liver mitochondria. In addition, methyltriclosan induces permeabilization of both mitochondrial membranes and the liposome membranes. Methyltriclosan, in contrast to triclosan, has a milder effect on organelles and their membranes. Possible mechanisms of methyltriclosan effects on mitochondria and liposomes are discussed.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"147 - 155"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426622","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 Effects of Dicyclohexylcarbamimidoyl Oximes on the Properties of Model Lipid Membranes","authors":"S. S. Efimova,&nbsp;D. A. Chernyshova,&nbsp;Z. M. Sarkisyan,&nbsp;P. Brémond,&nbsp;O. S. Ostroumova","doi":"10.1134/S1990747821020045","DOIUrl":"10.1134/S1990747821020045","url":null,"abstract":"<p>The molecular mechanisms of action of dicyclohexyl-containing derivatives of O-iminoisourea, (<i>E</i>)-O-(N,N'-dicyclohexylcarbamimidoyl) oxime of cyclohexanone (<b><i>1</i></b>), (<i>E</i>)-O-(N,N'-dicyclohexylcarbodimide) oxime of propane-2-one (<b><i>2</i></b>) and (1-(<i>E</i>)-[(<i>E</i>)-(N,N'- dicyclohexylcarbamimidoyl)oxy]imino-1-(pyridine-4-yl)ethane (<b><i>3</i></b>), on model lipid membranes, unilamellar vesicles and planar lipid bilayers, were investigated. It was found that all the tested compounds did not affect the electrical properties of uncharged membranes of 1-palmitoyl-2-oleyl-<i>sn</i>-glycerol-3-phosphocholine (POPC), while oxime <b><i>2</i></b> at a concentration more than 0.2 mM increased the boundary potential of negatively charged membranes of 1-palmitoyl-2-oleyl-<i>sn</i>-glycerol-3-phospho-1'-rac-glycerol (POPG) by 40 mV. It was shown that the ability of the oximes to induce leakage of a fluorescent probe calcein from POPC liposomes at the equimolar oxime/lipid ratio decreased in the order <b><i>2</i></b> &gt; <b><i>1</i></b> ≈ <b><i>3</i></b> from 25 to 15%. Compound <b><i>2</i></b> released up to 50% of the total calcein captured by POPG vesicles, while compounds <b><i>1</i></b> and <b><i>3</i></b> released no more than 15% of the probe. The observed differences in the ability of compound <b><i>2</i></b> to cause leakage of the probe from POPC and POPG liposomes can be explained by the formation of ion permeable pores in the POPG membranes. A higher efficiency of compound <b><i>2</i></b> compared to compounds <b><i>1</i></b> and <b><i>3</i></b> was due to the disordering effect of compound <b><i>2</i></b> on the lipid bilayers, which was confirmed by the data of differential scanning microcalorimetry. The results obtained are important in choosing a matrix for further chemical modification in the development of anticancer drugs based on dicyclohexylcarbamimidoyl.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"167 - 174"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4425381","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":"Boundary Potential and the Energy of Lipid Monolayer Compression at the Liquid Expanded State","authors":"Yu. A. Ermakov","doi":"10.1134/S1990747821020057","DOIUrl":"10.1134/S1990747821020057","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Compression diagrams were obtained and analyzed for monolayers composed from DOPC, POPC, DMPC, DPPC, DPhPC, and DMPS at the surface of solutions containing KCl, CaCl₂, or BeCl₂ and in the presence of polylysine (PLL) or chlorpromazine (CPZ). Elastic properties of monolayers are characterized by the area of lipid molecules, presented as an incompressible area with a soft shell, the size of which exponentially depends on the lateral pressure and the coefficient of elasticity. This assumption describes well the shape of the lipid compression diagrams, including lipids with saturated hydrocarbon chains (DPPC and DMPS) in the region, where they exhibit liquid crystal properties (liquid expanded state, LE). All lipids show changes in the interfacial Volta potential in this region; these changes linearly depend on the effective value of the work applied to compress the monolayer. Choosing for zero value of the Volta potential its magnitude at the point with a lateral pressure of about 1 mN/m, the slope of linear section of this dependence was estimated. The slope of this dependence makes it possible to identify different types of membrane-active compounds affecting the elastic and electrostatic characteristics of the monolayer. It turned out that this slope is practically independent of the pH and ionic composition of the aqueous subphase but decreases upon adsorption of PLL polypeptides on the surface of the DMPS monolayer. The adsorption of small positively charged CPZ molecules on this monolayer leads to the deviation in the potential vs work dependence from the linear. A quantitative description of this deviation is in a good agreement with the assumption that CPZ molecules are incorporated into the monolayer. Their contribution to the change in the energy of the monolayer and the Volta potential is determined by the amount of incorporated CPZ molecules, the effect of which on lateral pressure can be approximated by a function similar to the Boltzmann relation.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"130 - 141"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426289","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":"Malondialdehyde but Not Methylglyoxal Impairs Insulin Signaling, NO Production, and Endothelial Barrier","authors":"M. V. Samsonov,&nbsp;N. V. Podkuychenko,&nbsp;V. Z. Lankin,&nbsp;A. V. Vorotnikov,&nbsp;V. P. Shirinsky","doi":"10.1134/S1990747821030089","DOIUrl":"10.1134/S1990747821030089","url":null,"abstract":"<p>Dyslipidemia and hyperglycemia portray “cause-and-consequence” of type 2 diabetes mellitus (T2DM). They are linked to malondialdehyde (MDA) and methylglyoxal (MGO) generation that result from membrane lipid peroxidation and oxidative glucose conversions. We compared the effects of exogenous MDA and MGO on human umbilical vein endothelial cells and found that MDA but not MGO impairs insulin activation of PI3-kinase pathway, NO production, and endothelial barrier capacity. MDA abolished insulin activation of Akt and eNOS but not that of IRS. These results substantiate the hypothesis that MDA may be involved in endothelial dysfunction as an early event in the development of T2DM.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"195 - 200"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426624","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":"Interaction of Peptides Containing CRAC Motifs with Lipids in Membranes of Various Composition","authors":"P. E. Volynsky,&nbsp;T. R. Galimzyanov,&nbsp;S. A. Akimov","doi":"10.1134/S1990747821010074","DOIUrl":"10.1134/S1990747821010074","url":null,"abstract":"<p>The lateral distribution of integral and peripheral proteins, as well as lipids in the plasma membranes of mammalian cells is extremely heterogeneous. It is believed that various lipid-protein domains are formed in membranes. Domains enriched in sphingomyelin and cholesterol are called rafts. It is assumed that the distribution of proteins into rafts is largely related to the presence in their primary sequence of a specific amino acid region called the CRAC motif, which is responsible for cholesterol binding. In this work, the interaction of two peptides containing CRAC motifs in their structure with membranes of different compositions was studied by means of molecular dynamics. It has been shown that the average number of lipid molecules in contact with each peptide is proportional to the mole fraction of lipid in the membrane. The predominant interaction of peptides with cholesterol was not observed. In addition, cholesterol did not form long-lived contacts with any amino acid or amino acid sequence. We suppose that in some cases the predominant lateral distribution of peptides and proteins containing CRAC motifs into rafts may be due to amphipathicity of the CRAC motif rather than due to specific strong binding of cholesterol.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"120 - 129"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1990747821010074.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Glucocorticoid Deflazacort on Respiration and Calcium-Dependent Permeability of Rat Liver Mitochondria","authors":"M. V. Dubinin,&nbsp;A. A. Semenova,&nbsp;E. I. Khoroshavina,&nbsp;K. N. Belosludtsev","doi":"10.1134/S1990747821020033","DOIUrl":"10.1134/S1990747821020033","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>This study examines the effect of glucocorticoid deflazacort on the functioning of rat liver mitochondria. Deflazacort at concentrations up to 100 μM has been shown to have no effect on respiration and oxidative phosphorylation of rat liver mitochondria, energized both in the presence of glutamate/malate (substrates of complex I of the respiratory chain) and succinate (substrate of complex II of the respiratory chain), and also does not affect activity of complexes of the respiratory chain of organelles. It was found that deflazacort does not affect the permeability of the inner membrane of liver mitochondria, but reduces the resistance of organelles to the induction of calcium-dependent MPT pore. In addition, we have found that this glucocorticoid is able to induce a decrease in the level of mitochondrial NAD(P)H, as well as inhibit the production of hydrogen peroxide by organelles. The paper discusses how the effects of deflazacort on mitochondrial function may be related to the therapeutic effects of this agent.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"156 - 166"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426623","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 and Functions of Gap Junctions and Their Constituent Connexins in the Mammalian CNS","authors":"E. Yu. Kirichenko,&nbsp;S. N. Skatchkov,&nbsp;A. M. Ermakov","doi":"10.1134/S1990747821020069","DOIUrl":"10.1134/S1990747821020069","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Numerous data obtained in the last 20 years indicate that all parts of the mature central nervous system, from the retina and olfactory bulb to the spinal cord and brain, contain cells connected by gap junctions (GJs). The morphological basis of the GJs is a group of joined membrane hemichannels called connexons, the subunit of each connexon is the protein connexin. In the central nervous system, connexins show specificity and certain types of them are expressed either in neurons or in glial cells. Connexins and GJs of neurons, combining certain types of inhibitory hippocampal and neocortical neuronal ensembles, provide synchronization of local impulse and rhythmic activity, thalamocortical conduction, control of excitatory connections, which reflects their important role in the processes of perception, concentration of attention and consolidation of memory, both on the cellular and at the system level. Connexins of glial cells are ubiquitously expressed in the brain, and the GJs formed by them provide molecular signaling and metabolic cooperation and play a certain role in the processes of neuronal migration during brain development, myelination, tissue homeostasis, and apoptosis. At the same time, mutations in the genes of glial connexins, as well as a deficiency of these proteins, are associated with such diseases as congenital neuropathies, hearing loss, skin diseases, and brain tumors. This review summarizes the existing data of numerous molecular, electrophysiological, pharmacological, and morphological studies aimed at progress in the study of the physiological and pathophysiological significance of glial and neuronal connexins and GJs for the central nervous system.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"107 - 119"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1990747821020069.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induction Changes of Chlorophyll Fluorescence in Chara Cells Related to Metabolite Exchange between Chloroplasts and Cytoplasmic Flow","authors":"A. A. Bulychev","doi":"10.1134/S199074782103003X","DOIUrl":"10.1134/S199074782103003X","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Induction changes in chlorophyll fluorescence are associated with photosynthetic electron transfer, generation of the transmembrane proton gradient, and production of carbohydrates in the CO₂ fixation cycle. The reactions of photosynthesis are also accompanied by the outflow of photoproducts from illuminated chloroplasts and their long-distance transport. The exchange of metabolites across the chloroplast envelope membranes is carried out by transporters that are active in the light and cease to operate in darkness. Inactivation of light-dependent envelope transporters in <i>Chara</i> cells interrupts spatial signaling manifested as a transient fluorescence rise in response to illumination of a distant cell area. The dark adaptation was found to down-regulate the entry of metabolites from the streaming cytoplasm into shaded chloroplasts but had rather low influence on metabolite export from illuminated plastids. Fluorescence induction curves were quite sensitive to illumination or darkening of the sample area residing outside the region of photometric assay. The amplitude of slow fluorescence changes observed under dim illumination of the whole <i>Chara</i> internode was substantially larger than under narrow-field illumination of the fluorescence assay region. The results indicate that the slow increase in fluorescence during the induction period in characean cells results not only from photosynthetic activity of chloroplasts in the examined cell region but also from interactions between the analyzed and neighboring cell areas. When the cytoplasmic streaming was arrested by cytochalasin D, similar induction changes were induced by local and global illumination, indicating a disruption of long-range interactions. The results suggest that the liquid flow not only carries metabolites from illuminated to shaded cell parts but also facilitates the export of photometabolites from chloroplasts to the cytoplasm.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"184 - 194"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4426295","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 Ionic Strength on Adsorption of Polypeptides on Lipid Membranes: Theoretical Analysis","authors":"R. J. Molotkovsky,&nbsp;T. R. Galimzyanov,&nbsp;Yu. A. Ermakov","doi":"10.1134/S1990747821030053","DOIUrl":"10.1134/S1990747821030053","url":null,"abstract":"<p>Theoretical analysis of the effect of the ionic strength of a solution on the surface (zeta) potential of liposomes formed by an anionic phospholipid (cardiolipin) with adsorbed polycations has been carried out. The experimental data were previously measured by the electrokinetic method in the presence of polylysine molecules of different molecular weights and a supporting electrolyte, KCl, at concentrations of 10, 40, and 100 mM. To approximate the experimental dependences of the potential on the amount of polylysine in the suspension, we used a theoretical model with parameters, among which the most physically significant are the thickness of the polymer layer, the adsorption constant, and the fraction of the surface of lipid membranes occupied by the polypeptide at the saturation. The found values of the model parameters demonstrate the effect of the length of the polypeptide molecules on the structure of the polymer layer varying from homogeneous to clustered distribution over the surface. A noticeable decrease in the efficiency of adsorption with an increase in the ionic strength of the solution is explained by the conformational rearrangements of the macromolecules on the surface and a decrease in the area of the surface available for their adsorption upon the saturation.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"175 - 183"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4422164","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":"Styryl Dyes di-4-ANEPPS and RH-421 as Sensors of the Protons on the Surface of Lipid Membranes","authors":"A. N. Konstantinova,&nbsp;Yu. V. Kharitonova,&nbsp;V. Yu. Tashkin,&nbsp;V. S. Sokolov","doi":"10.1134/S1990747821020070","DOIUrl":"10.1134/S1990747821020070","url":null,"abstract":"<p>It has been shown that electrochromic styryl dyes can be used as probes to study proton binding on the membrane surface. These dyes are adsorbed on the membrane as neutral molecules with a significant dipole moment, due to which a dipole potential jump occurs at the boundary of the membrane with the solution. A decrease in pH led to the disappearance of both this potential jump and fluorescence of the membrane-bound molecules of dyes di-4-ANEPPS and RN-421. This can be explained by the inability of protonated dye molecules formed at low pH to adsorb on lipid membranes. The dependence of the dipole potential jump on pH was measured in the experiment to estimate pK of the dyes, which was estimated to be about 4.5. Desorption of the dye molecules from the surface of the lipid membrane occurred not only under the solution pH decrease, but also upon photoactivated release of protons on the membrane surface caused by photolysis of the caged-H⁺ molecules of sodium 2-methoxy-5-nitrophenyl sulfate. This indicated a significant increase in the concentration of protons on the surface of the lipid membrane caused by this process.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"15 2","pages":"142 - 146"},"PeriodicalIF":0.5,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4731415","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}