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Papers by Alexander Yusipovich
International Journal of Molecular Sciences
The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At th... more The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At the beginning of the review, the basic concepts of biological methods of environmental monitoring, namely bioanalytical and biomonitoring methods, are briefly considered. The main part of the review describes the basic principles and concepts of vibration spectroscopy and microspectrophotometry, in particular IR spectroscopy, mid- and near-IR spectroscopy, IR microspectroscopy, Raman spectroscopy, resonance Raman spectroscopy, Surface-enhanced Raman spectroscopy, and Raman microscopy. Examples of the use of various methods of vibration spectroscopy for the study of biological samples, especially in the context of environmental monitoring, are given. Based on the described results, the authors conclude that the near-IR spectroscopy-based methods are the most convenient for environmental studies, and the relevance of the use of IR and Raman spectroscopy in environmental monitoring will incre...
Hormone Research in Paediatrics, 2012
Hormone Research in Paediatrics, 2016
Laser Physics Letters, 2016
We used 3D phase images obtained by laser interference microscopy (LIM) for ex vivo evaluation of... more We used 3D phase images obtained by laser interference microscopy (LIM) for ex vivo evaluation of changes in the structure of myelin during repetitive stimulation. In this work we propose a simple model of myelinated nerve fiber (mNF), which describes phase images as a result of different geometry and membrane-to-cytoplasm ratio in various regions, particularly, the internode and paranodal–nodal–paranodal region, including the node of Ranvier. Application of this model provides clear interpretation of the phase images and also demonstrates that repetitive action potentials are accompanied by structural changes in myelin in the internode and cytoplasmic modification in the node of Ranvier. The first 20 min of stimulation did not induce significant changes in the measured parameters, but then the optical path difference at the periphery of mNF and at the node of Ranvier declined reversibly. We believe that our model is also applicable to other modifications of interference and non-interference imaging.
Biochemistry (Moscow)
Binding of dinitrosyl iron complex (DNIC) to albumin was studied using time-resolved fluorescence... more Binding of dinitrosyl iron complex (DNIC) to albumin was studied using time-resolved fluorescence (TRF) and electron spin resonance (ESR) spectroscopy. It was found that the fluorescence lifetime of bovine serum albumin (BSA) and human serum albumin (HSA) decreases with binding and depends on DNIC concentration. The observed biexponential pattern of the BSA tryptophan (Trp) fluorescence decay is explained by the presence of two tryptophan residues in the protein molecule. We believe that DNIC forms stable complexes with the cysteine (Cys34) residue in the domain I of albumin. It was shown that the lifetime of albumin tryptophan fluorescence decreased during co-incubation of BSA with DNICs and glutathione. Effects of DNIC on the binding of specific spin-labeled fatty acids with albumin in human blood plasma were studied in vitro. The presence of DNIC in blood plasma does not change conformation of albumin domains II and III. We suggest that the most possible interaction between DNICs and albumin is the formation of a complex; and nitrosylation of the cysteine residue in the albumin domain I occurs without the changes in albumin conformation.
58th Annual ESPE Meeting (ESPE 2019), 2019
Instruments and Experimental Techniques, 2021
Aerospace and Environmental Medicine, 2019
Pflügers Archiv - European Journal of Physiology, 2013
Previously, we reported that in mammalian erythrocytes irreversible annealing of spectrin heterod... more Previously, we reported that in mammalian erythrocytes irreversible annealing of spectrin heterodimers at 49-50°C abolished cell volume-dependent regulation of ion carriers, thus suggesting an implication of a twodimensional (2D) membrane carcass in volume sensing and/or signal transduction. To further examine this hypothesis, we employed atomic force microscopy. This method revealed folded membrane relief of fixed human erythrocytes with an average wave height of 3-5 nm covered by globular structures with a diameter of 40-50 nm and an average height of 1-2 nm. Erythrocyte swelling caused by reduction of medium osmolality decreased the height of membrane surface waves by 40 % and increased K + ,Cl − cotransport by approximately sixfold. Both volumesensitive changes of membrane relief and activity of K + , Cl − cotransporter were abolished by a 10-min preincubation at 50°C. Our results strongly suggest that volumedependent alterations of the human erythrocyte membrane relief are caused by reorganization of the 2D spectrin-actin network contributing to regulation of the activity of volumesensitive ion transporters.
Applied Biochemistry and Microbiology, 2012
Moscow University Biological Sciences Bulletin
The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-lo... more The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-loop, exhibiting reduced efficiency of electron transfer, were studied. CD spectroscopy studies showed that the ordering of mutant structure increases by 3–6% compared to that of the WT molecules due to the higher content of β-structural elements. The IR spectroscopy data are consistent with the CD results and demonstrate that some α-helical elements change into β-structures, and the amount of the non-structured elements is decreased. The analysis of the 1H-NMR spectra demonstrated that cytochrome c mutants have a well-determined secondary structure with some specific features related to changes in the heme microenvironment. The observed changes in the structure of cytochrome c mutants are likely to be responsible for the decrease in the conformational mobility of the P76GTKMIFA83 sequence carrying mutations and for the decline in succinate:cytochrome c-reductase and cytochrome c-oxidase a...
Moscow University Chemistry Bulletin, 2015
Raman spectroscopy (RS) in conjunction with silver nanoparticles (SNPs) is a sensitive method for... more Raman spectroscopy (RS) in conjunction with silver nanoparticles (SNPs) is a sensitive method for diagnostics of hemoglobin in biomedicine. It is shown that the applicability of this method with the injec tion of SNPs into the body is limited due to adverse effects on the capacity of hemoglobin to transport O 2. The use of nanostructured silver substrates is a more effective and native way to study hemoglobin conforma tion without requiring injection of SNPs into the body.
Hormone Research in Paediatrics, 2015
We study certain nonlinear continuous models of opinion formation derived from a kinetic descript... more We study certain nonlinear continuous models of opinion formation derived from a kinetic description involving exchange of opinion between individual agents. These models imply that the only possible final opinions are the extremal ones, and are similar to models of pure drift in magnetization. Both analytical and numerical methods allow to recover the final distribution of opinion between the two extremal ones.
International Journal of Molecular Sciences
The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At th... more The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At the beginning of the review, the basic concepts of biological methods of environmental monitoring, namely bioanalytical and biomonitoring methods, are briefly considered. The main part of the review describes the basic principles and concepts of vibration spectroscopy and microspectrophotometry, in particular IR spectroscopy, mid- and near-IR spectroscopy, IR microspectroscopy, Raman spectroscopy, resonance Raman spectroscopy, Surface-enhanced Raman spectroscopy, and Raman microscopy. Examples of the use of various methods of vibration spectroscopy for the study of biological samples, especially in the context of environmental monitoring, are given. Based on the described results, the authors conclude that the near-IR spectroscopy-based methods are the most convenient for environmental studies, and the relevance of the use of IR and Raman spectroscopy in environmental monitoring will incre...
Hormone Research in Paediatrics, 2012
Hormone Research in Paediatrics, 2016
Laser Physics Letters, 2016
We used 3D phase images obtained by laser interference microscopy (LIM) for ex vivo evaluation of... more We used 3D phase images obtained by laser interference microscopy (LIM) for ex vivo evaluation of changes in the structure of myelin during repetitive stimulation. In this work we propose a simple model of myelinated nerve fiber (mNF), which describes phase images as a result of different geometry and membrane-to-cytoplasm ratio in various regions, particularly, the internode and paranodal–nodal–paranodal region, including the node of Ranvier. Application of this model provides clear interpretation of the phase images and also demonstrates that repetitive action potentials are accompanied by structural changes in myelin in the internode and cytoplasmic modification in the node of Ranvier. The first 20 min of stimulation did not induce significant changes in the measured parameters, but then the optical path difference at the periphery of mNF and at the node of Ranvier declined reversibly. We believe that our model is also applicable to other modifications of interference and non-interference imaging.
Biochemistry (Moscow)
Binding of dinitrosyl iron complex (DNIC) to albumin was studied using time-resolved fluorescence... more Binding of dinitrosyl iron complex (DNIC) to albumin was studied using time-resolved fluorescence (TRF) and electron spin resonance (ESR) spectroscopy. It was found that the fluorescence lifetime of bovine serum albumin (BSA) and human serum albumin (HSA) decreases with binding and depends on DNIC concentration. The observed biexponential pattern of the BSA tryptophan (Trp) fluorescence decay is explained by the presence of two tryptophan residues in the protein molecule. We believe that DNIC forms stable complexes with the cysteine (Cys34) residue in the domain I of albumin. It was shown that the lifetime of albumin tryptophan fluorescence decreased during co-incubation of BSA with DNICs and glutathione. Effects of DNIC on the binding of specific spin-labeled fatty acids with albumin in human blood plasma were studied in vitro. The presence of DNIC in blood plasma does not change conformation of albumin domains II and III. We suggest that the most possible interaction between DNICs and albumin is the formation of a complex; and nitrosylation of the cysteine residue in the albumin domain I occurs without the changes in albumin conformation.
58th Annual ESPE Meeting (ESPE 2019), 2019
Instruments and Experimental Techniques, 2021
Aerospace and Environmental Medicine, 2019
Pflügers Archiv - European Journal of Physiology, 2013
Previously, we reported that in mammalian erythrocytes irreversible annealing of spectrin heterod... more Previously, we reported that in mammalian erythrocytes irreversible annealing of spectrin heterodimers at 49-50°C abolished cell volume-dependent regulation of ion carriers, thus suggesting an implication of a twodimensional (2D) membrane carcass in volume sensing and/or signal transduction. To further examine this hypothesis, we employed atomic force microscopy. This method revealed folded membrane relief of fixed human erythrocytes with an average wave height of 3-5 nm covered by globular structures with a diameter of 40-50 nm and an average height of 1-2 nm. Erythrocyte swelling caused by reduction of medium osmolality decreased the height of membrane surface waves by 40 % and increased K + ,Cl − cotransport by approximately sixfold. Both volumesensitive changes of membrane relief and activity of K + , Cl − cotransporter were abolished by a 10-min preincubation at 50°C. Our results strongly suggest that volumedependent alterations of the human erythrocyte membrane relief are caused by reorganization of the 2D spectrin-actin network contributing to regulation of the activity of volumesensitive ion transporters.
Applied Biochemistry and Microbiology, 2012
Moscow University Biological Sciences Bulletin
The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-lo... more The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-loop, exhibiting reduced efficiency of electron transfer, were studied. CD spectroscopy studies showed that the ordering of mutant structure increases by 3–6% compared to that of the WT molecules due to the higher content of β-structural elements. The IR spectroscopy data are consistent with the CD results and demonstrate that some α-helical elements change into β-structures, and the amount of the non-structured elements is decreased. The analysis of the 1H-NMR spectra demonstrated that cytochrome c mutants have a well-determined secondary structure with some specific features related to changes in the heme microenvironment. The observed changes in the structure of cytochrome c mutants are likely to be responsible for the decrease in the conformational mobility of the P76GTKMIFA83 sequence carrying mutations and for the decline in succinate:cytochrome c-reductase and cytochrome c-oxidase a...
Moscow University Chemistry Bulletin, 2015
Raman spectroscopy (RS) in conjunction with silver nanoparticles (SNPs) is a sensitive method for... more Raman spectroscopy (RS) in conjunction with silver nanoparticles (SNPs) is a sensitive method for diagnostics of hemoglobin in biomedicine. It is shown that the applicability of this method with the injec tion of SNPs into the body is limited due to adverse effects on the capacity of hemoglobin to transport O 2. The use of nanostructured silver substrates is a more effective and native way to study hemoglobin conforma tion without requiring injection of SNPs into the body.
Hormone Research in Paediatrics, 2015
We study certain nonlinear continuous models of opinion formation derived from a kinetic descript... more We study certain nonlinear continuous models of opinion formation derived from a kinetic description involving exchange of opinion between individual agents. These models imply that the only possible final opinions are the extremal ones, and are similar to models of pure drift in magnetization. Both analytical and numerical methods allow to recover the final distribution of opinion between the two extremal ones.