Волынский Павел Евгеньевич

Образование

Период обученияСтрана, городУчебное заведениеДополнительная информация
1991–1997 Россия, Долгопрудный, Московская обл. Московский Физико-Технический Институт (Государственный университет). Факультет физико-химической биологии.

Избранные публикации

  1. Dubovskii P.V., Dubinnyi M.A., Volynsky P.E., Pustovalova Y.E., Konshina A.G., Utkin Y.N., Arseniev A.S., Efremov R.G. (2017). Impact of membrane partitioning on the spatial structure of an S-type cobra cytotoxin. J. Biomol. Struct. Dyn. , 1–16 [+]

    Cobra cytotoxins (CTs) belong to the three-fingered protein family. They are classified into S- and P-types, the latter exhibiting higher membrane-perturbing capacity. In this work, we investigated the interaction of CTs with phospholipid bilayers, using coarse-grained (CG) and full-atom (FA) molecular dynamics (MD). The object of this work is a CT of an S-type, cytotoxin I (CT1) from N.oxiana venom. Its spatial structure in aqueous solution and in the micelles of dodecylphosphocholine (DPC) were determined by (1)H-NMR spectroscopy. Then, via CG- and FA MD-computations, we evaluated partitioning of CT1 molecule into palmitoyloleoylphosphatidylcholine (POPC) membrane, using the toxin spatial models, obtained either in aqueous solution, or detergent micelle. The latter model exhibits minimal structural changes upon partitioning into the membrane, while the former deviates from the starting conformation, loosing the tightly bound water molecule in the loop-2. These data show that the structural changes elicited by CT1 molecule upon incorporation into DPC micelle take place likely in the lipid membrane, although the mode of the interaction of this toxin with DPC micelle (with the tips of the all three loops) is different from its mode in POPC membrane (primarily with the tip of the loop-1 and both the tips of the loop-1 and loop-2).

    ID:1943
  2. Akimov S.A., Volynsky P.E., Galimzyanov T.R., Kuzmin P.I., Pavlov K.V., Batishchev O.V. (2017). Pore formation in lipid membrane II: Energy landscape under external stress. Sci Rep 7 (1), 12509 [+]

    Lipid membranes are extremely stable envelopes allowing cells to survive in various environments and to maintain desired internal composition. Membrane permeation through formation of transversal pores requires substantial external stress. Practically, pores are usually formed by application of lateral tension or transmembrane voltage. Using the same approach as was used for obtaining continuous trajectory of pore formation in the stress-less membrane in the previous article, we now consider the process of pore formation under the external stress. The waiting time to pore formation proved a non-monotonous function of the lateral tension, dropping from infinity at zero tension to a minimum at the tension of several millinewtons per meter. Transmembrane voltage, on the contrary, caused the waiting time to decrease monotonously. Analysis of pore formation trajectories for several lipid species with different spontaneous curvatures and elastic moduli under various external conditions provided instrumental insights into the mechanisms underlying some experimentally observed phenomena.

    ID:1941
  3. Akimov S.A., Volynsky P.E., Galimzyanov T.R., Kuzmin P.I., Pavlov K.V., Batishchev O.V. (2017). Pore formation in lipid membrane I: Continuous reversible trajectory from intact bilayer through hydrophobic defect to transversal pore. Sci Rep 7 (1), 12152 [+]

    Lipid membranes serve as effective barriers allowing cells to maintain internal composition differing from that of extracellular medium. Membrane permeation, both natural and artificial, can take place via appearance of transversal pores. The rearrangements of lipids leading to pore formation in the intact membrane are not yet understood in details. We applied continuum elasticity theory to obtain continuous trajectory of pore formation and closure, and analyzed molecular dynamics trajectories of pre-formed pore reseal. We hypothesized that a transversal pore is preceded by a hydrophobic defect: intermediate structure spanning through the membrane, the side walls of which are partially aligned by lipid tails. This prediction was confirmed by our molecular dynamics simulations. Conversion of the hydrophobic defect into the hydrophilic pore required surmounting some energy barrier. A metastable state was found for the hydrophilic pore at the radius of a few nanometers. The dependence of the energy on radius was approximately quadratic for hydrophobic defect and small hydrophilic pore, while for large radii it depended on the radius linearly. The pore energy related to its perimeter, line tension, thus depends of the pore radius. Calculated values of the line tension for large pores were in quantitative agreement with available experimental data.

    ID:1942
  4. Mineev K.S., Goncharuk S.A., Goncharuk M.V., Volynsky P.E., Novikova E.V., Aresinev A.S. (2017). Spatial structure of TLR4 transmembrane domain in bicelles provides the insight into the receptor activation mechanism. Sci Rep 7 (1), 6864 [+]

    Toll-like receptors (TLRs) play a key role in the innate and adaptive immune systems. While a lot of structural data is available for the extracellular and cytoplasmic domains of TLRs, and a model of the dimeric full-length TLR3 receptor in the active state was build, the conformation of the transmembrane (TM) domain and juxtamembrane regions in TLR dimers is still unclear. In the present work, we study the transmembrane and juxtamembrane parts of human TLR4 receptor using solution NMR spectroscopy in a variety of membrane mimetics, including phospholipid bicelles. We show that the juxtamembrane hydrophobic region of TLR4 includes a part of long TM α-helix. We report the dimerization interface of the TM domain and claim that long TM domains with transmembrane charged aminoacids is a common feature of human toll-like receptors. This fact is analyzed from the viewpoint of protein activation mechanism, and a model of full-length TLR4 receptor in the dimeric state has been proposed.

    ID:1913
  5. Bocharov E.V., Bragin P.E., Pavlov K.V., Bocharova O.V., Mineev K.S., Polyansky A.A., Volynsky P.E., Efremov R.G., Arseniev A.S. (2017). The Conformation of the Epidermal Growth Factor Receptor Transmembrane Domain Dimer Dynamically Adapts to the Local Membrane Environment. Biochemistry 56 (12), 1697–1705 [+]

    The epidermal growth factor receptor (EGFR) family is an important class of receptor tyrosine kinases, mediating a variety of cellular responses in normal biological processes and in pathological states of multicellular organisms. Different modes of dimerization of the human EGFR transmembrane domain (TMD) in different membrane mimetics recently prompted us to propose a novel signal transduction mechanism based on protein-lipid interaction. However, the experimental evidence for it was originally obtained with slightly different TMD fragments used in the two different mimetics, compromising the validity of the comparison. To eliminate ambiguity, we determined the nuclear magnetic resonance (NMR) structure of the bicelle-incorporated dimer of the EGFR TMD fragment identical to the one previously used in micelles. The NMR results augmented by molecular dynamics simulations confirm the mutual influence of the TMD and lipid environment, as is required for the proposed lipid-mediated activation mechanism. They also reveal the possible functional relevance of a subtle interplay between the concurrent processes in the lipid and protein during signal transduction.

    ID:1780
  6. Bragin P.E., Mineev K.S., Bocharova O.V., Volynsky P.E., Bocharov E.V., Arseniev A.S. (2016). HER2 Transmembrane Domain Dimerization Coupled with Self-Association of Membrane-Embedded Cytoplasmic Juxtamembrane Regions. J. Mol. Biol. 428 (1), 52–61 [+]

    Receptor tyrosine kinases of the human epidermal growth factor receptor (HER or ErbB) family transduce biochemical signals across plasma membrane, playing a significant role in vital cellular processes and in various cancers. Inactive HER/ErbB receptors exist in equilibrium between the monomeric and unspecified pre-dimerized states. After ligand binding, the receptors are involved in strong lateral dimerization with proper assembly of their extracellular ligand-binding, single-span transmembrane, and cytoplasmic kinase domains. The dimeric conformation of the HER2 transmembrane domain that is believed to support the cytoplasmic kinase domain configuration corresponding to the receptor active state was previously described in lipid bicelles. Here we used high-resolution NMR spectroscopy in another membrane-mimicking micellar environment and identified an alternative HER2 transmembrane domain dimerization coupled with self-association of membrane-embedded cytoplasmic juxtamembrane region. Such a dimerization mode appears to be capable of effectively inhibiting the receptor kinase activity. This finding refines the molecular mechanism regarding the signal propagation steps from the extracellular to cytoplasmic domains of HER/ErbB receptors.

    ID:1369
  7. Chugunov A.O., Volynsky P.E., Krylov N.A., Nolde D.E., Efremov R.G. (2016). Temperature-sensitive gating of TRPV1 channel as probed by atomistic simulations of its trans- and juxtamembrane domains. Sci Rep 6, 33112 [+]

    Heat-activated transient receptor potential channel TRPV1 is one of the most studied eukaryotic proteins involved in temperature sensation. Upon heating, it exhibits rapid reversible pore gating, which depolarizes neurons and generates action potentials. Underlying molecular details of such effects in the pore region of TRPV1 is of a crucial importance to control temperature responses of the organism. Despite the spatial structure of the channel in both open (O) and closed (C) states is known, microscopic nature of channel gating and mechanism of thermal sensitivity are still poorly understood. In this work, we used unrestrained atomistic molecular dynamics simulations of TRPV1 (without N- and C-terminal cytoplasmic domains) embedded into explicit lipid bilayer in its O- and C-states. We found that the pore domain with its neighboring loops undergoes large temperature-dependent conformational transitions in an asymmetric way, when fragments of only one monomer move with large amplitude, freeing the pore upon heating. Such an asymmetrical gating looks rather biologically relevant because it is faster and more reliable than traditionally proposed "iris-like" symmetric scheme of channel opening. Analysis of structural, dynamic, and hydrophobic organization of the pore domain revealed entropy growth upon TRPV1 gating, which is in line with current concepts of thermal sensitivity.

    ID:1558
  8. Kuznetsov A.S., Polyansky A.A., Fleck M., Volynsky P.E., Efremov R.G. (2015). Adaptable Lipid Matrix Promotes Protein-Protein Association in Membranes. J. Chem. Theory Comput. 11 (9), 4415–26 [+]

    Трансмембранные домены играют важную роль в функционировании мембранных белков. Их взаимодействия определяют работу ряда важнейших рецепторов, в частности, рецепторных тирозинкиназ. В настоящей работе на примере гликофорина А и двух модельних пептидов показали, что липидный бислой играет важную роль в димеризации трансмембранных спиралей. Встраивание пептида в мембрану вызывает формирование характерных неоднородностей в последней. Таким образом, димеризация трансмембранных спиралей может носить энтропийный характер.

    ID:1342
  9. Kuznetsov A.S., Volynsky P.E., Efremov R.G. (2015). Role of the Lipid Environment in the Dimerization of Transmembrane Domains of Glycophorin A. Acta Naturae 7 (4), 122–7 [+]

    An efficient computational approach is developed to quantify the free energy of a spontaneous association of the α-helices of proteins in the membrane environment. The approach is based on the numerical decomposition of the free energy profiles of the transmembrane (TM) helices into components corresponding to protein-protein, protein-lipid, and protein-water interactions. The method was tested for the TM segments of human glycophorin A (GpA) and two mutant forms, Gly83Ala and Thr87Val. It was shown that lipids make a significant negative contribution to the free energy of dimerization, while amino acid residues forming the interface of the helix-helix contact may be unfavorable in terms of free energy. The detailed balance between different energy contributions is highly dependent on the amino acid sequence of the TM protein segment. The results show the dominant role of the environment in the interaction of membrane proteins that is changing our notion of the driving force behind the spontaneous association of TM α-helices. Adequate estimation of the contribution of the water-lipid environment thus becomes an extremely urgent task for a rational design of new molecules targeting bitopic membrane proteins, including receptor tyrosine kinases.

    ID:1396
  10. Alekseeva A.S., Korotaeva A.A., Samoilova E.V., Volynsky P.E., Vodovozova E.L., Boldyrev I.A. (2014). Secretory phospholipase A2 activity in blood serum: The challenge to sense. Biochem. Biophys. Res. Commun. 454 (1), 178–182 [+]

    Excess levels of secretory phospholipase A2 (sPLA2) is known to contribute to several inflammatory diseases including vascular inflammation correlating with coronary events in coronary artery disease. Thus a method to monitor sPLA2 activity in blood serum is urgently needed. Such method is still a challenge since existing fluorescent probes do not allow to monitor sPLA2 activity directly in blood serum. Here we analyze and overcome barriers in sPLA2 sensing methodology and report a fluorescent probe and a kinetic model of its hydrolysis by sPLA2. New probe is designed with a fluorophore and a quencher not interfering binding to the enzyme. At the same time phospholipid matrix bearing the probe promotes efficient initial quenching of the fluorophore. Kinetic model of probe hydrolysis takes into account signal change due to the side processes. The probe and the kinetic model applied together prove the concept that the activity of sPLA can be measured directly in blood serum.

    ID:1124
  11. Polyansky A.A., Chugunov A.O., Volynsky P.E., Krylov N.A., Nolde D.E., Efremov R.G. (2014). PREDDIMER: a web server for prediction of transmembrane helical dimers. Bioinformatics 30 (6), 889–90 [+]

    Here we present PREDDIMER, a web tool for prediction of dimer structure of transmembrane (TM) helices. PREDDIMER allows (i) reconstruction of a number of dimer structures for given sequence(s) of TM protein fragments, (ii) ranking and filtering of predicted structures according to respective values of a scoring function, (iii) visualization of predicted 3D dimer structures and (iv) visualization of surface hydrophobicity of TM helices and their contacting (interface) regions represented as 2D maps.

    ID:975
  12. Chugunov A.O., Volynsky P.E., Krylov N.A., Boldyrev I.A., Efremov R.G. (2014). Liquid but Durable: Molecular Dynamics Simulations Explain the Unique Properties of Archaeal-Like Membranes. Sci Rep 4, 7462 [+]

    Археи, прежде известные как архебактерии, в основном являются экстремофилами: их среда обитания — это высокие температура, давление, соленость и кислотность. Возможно, «особый путь» архей был определен необычными свойствами их мембран, существенно отличающихся по составу от «обычных» фосфолипидов у бактерий и эукариот. В Лаборатории моделирования биомолекулярных систем ИБХ РАН провели компьютерное исследование архейных мембран, объяснив взаимосвязь между химической структурой липидов и физическими свойствами мембран. Статья опубликована в журнале Scientific Reports. По ее материалам написан пресс-релиз: «Прочные, но гибкие: молекулярная динамика объясняет уникальность биомембран архей».

    ID:1110
  13. Volynsky P.E., Polyansky A.A., Fakhrutdinova G.N., Bocharov E.V., Efremov R.G. (2013). Role of Dimerization Efficiency of Transmembrane Domains in Activation of Fibroblast Growth Factor Receptor 3. J. Am. Chem. Soc. , [+]

    Mutations in transmembrane (TM) domains of receptor tyrosine kinases are shown to cause a number of inherited diseases and cancer development. Here, we use a combined molecular modeling approach to understand molecular mechanism of effect of G380R and A391E mutations on dimerization of TM domains of human fibroblast growth factor receptor 3 (FGFR3). According to results of Monte Carlo conformational search in the implicit membrane and further molecular dynamics simulations, TM dimer of this receptor is able to form a number of various conformations, which differ significantly by the free energy of association in a full-atom model bilayer. The aforementioned mutations affect dimerization efficiency of TM segments and lead to repopulation of conformational ensemble for the dimer. Particularly, both mutations do not change the dimerization free energy of the predominant (putative "non-active") symmetric conformation of TM dimer, while affect dimerization efficiency of its asymmetric ("intermediate") and alternative symmetric (putative "active") models. Results of our simulations provide novel atomistic prospective of the role of G380 and A391E mutations in dimerization of TM domains of FGFR3 and their consecutive contributions to the activation pathway of the receptor.

    ID:972
  14. Polyansky A.A., Volynsky P.E., Efremov R.G. (2012). Multistate organization of transmembrane helical protein dimers governed by the host membrane. J. Am. Chem. Soc. 134 (35), 14390–400 [+]

    Association of transmembrane (TM) helices taking place in the cell membrane has an important contribution to the biological function of bitopic proteins, among which receptor tyrosine kinases represent a typical example and a potent target for medical applications. Since this process depends on a complex interplay of different factors (primary structures of TM domains and juxtamembrane regions, composition and phase of the local membrane environment, etc.), it is still far from being fully understood. Here, we present a computational modeling framework, which we have applied to systematically analyze dimerization of 18 TM helical homo- and heterodimers of different bitopic proteins, including the family of epidermal growth factor receptors (ErbBs). For this purpose, we have developed a novel surface-based modeling approach, which not only is able to predict particular conformations of TM dimers in good agreement with experiment but also provides screening of their conformational heterogeneity. Using all-atom molecular dynamics simulations of several of the predicted dimers in different model membranes, we have elucidated a putative role of the environment in selection of particular conformations. Simulation results clearly show that each particular bilayer preferentially stabilizes one of possible dimer conformations, and that the energy gain depends on the interplay between structural properties of the protein and the membrane. Moreover, the character of protein-driven perturbations of the bilayer is reflected in the contribution of a particular membrane to the free energy gain. We have found that the approximated dimerization strength for ErbBs family can be related to their oncogenic ability.

    ID:810
  15. Semenova A.A., Chugunov A.O., Dubovskii P.V., Chupin V.V., Volynsky P.E., Boldyrev I.A. (2011). The role of chain rigidity in lipid self-association: Comparative study of dihexanoyl- and disorbyl-phosphatidylcholines. Chem. Phys. Lipids 165, 382–386 [+]

    In the course of structure-function investigations of lipids a phosphatidylcholine molecule with short and rigid tails, di-2,4-hexadienoylphosphatidylcholine (DiSorbPC), was synthesized and studied in comparison with its saturated analog, dihexanoylphosphatidylcholine (DHPC). Conjugated double bonds in the acyl chains in DiSorbPC reduce considerably the number of possible conformers of the lipid within an aggregate. This leads to impaired packing of unsaturated acyl chains and thus, to a surprisingly high (115Å(2)) area per molecule for DiSorbPC at the air-water interface and failure to form micelles of regular size and shape. Details on DiSorbPC aggregation and packing provided by a set of experimental techniques combined with molecular dynamics simulations are presented.

    ID:669
  16. Bocharov E.V., Mayzel M.L., Volynsky P.E., Mineev K.S., Tkach E.N., Ermolyuk Y.S., Schulga A.A., Efremov R.G., Arseniev A.S. (2010). Left-handed dimer of EphA2 transmembrane domain: Helix packing diversity among receptor tyrosine kinases. Biophys. J. 98 (5), 881–9 [+]

    The Eph receptor tyrosine kinases and their membrane-bound ephrin ligands control a diverse array of cell-cell interactions in the developing and adult organisms. During signal transduction across plasma membrane, Eph receptors, like other receptor tyrosine kinases, are involved in lateral dimerization and subsequent oligomerization presumably with proper assembly of their single-span transmembrane domains. Spatial structure of dimeric transmembrane domain of EphA2 receptor embedded into lipid bicelle was obtained by solution NMR, showing a left-handed parallel packing of the transmembrane helices (535-559)(2). The helices interact through the extended heptad repeat motif L(535)X(3)G(539)X(2)A(542)X(3)V(546)X(2)L(549) assisted by intermolecular stacking interactions of aromatic rings of (FF(557))(2), whereas the characteristic tandem GG4-like motif A(536)X(3)G(540)X(3)G(544) is not used, enabling another mode of helix-helix association. Importantly, a similar motif AX(3)GX(3)G as was found is responsible for right-handed dimerization of transmembrane domain of the EphA1 receptor. These findings serve as an instructive example of the diversity of transmembrane domain formation within the same family of protein kinases and seem to favor the assumption that the so-called rotation-coupled activation mechanism may take place during the Eph receptor signaling. A possible role of membrane lipid rafts in relation to Eph transmembrane domain oligomerization and Eph signal transduction was also discussed.

    ID:320
  17. Volynsky P.E., Mineeva E.A., Goncharuk M.V., Ermolyuk Y.S., Arseniev A.S., Efremov R.G. (2010). Computer simulations and modeling-assisted ToxR screening in deciphering 3D structures of transmembrane alpha-helical dimers: ephrin receptor A1. Phys Biol 7, 16014 [+]

    Membrane-spanning segments of numerous proteins (e.g. receptor tyrosine kinases) represent a novel class of pharmacologically important targets, whose activity can be modulated by specially designed artificial peptides, the so-called interceptors. Rational construction of such peptides requires understanding of the main factors driving peptide-peptide association in lipid membranes. Here we present a new method for rapid prediction of the spatial structure of transmembrane (TM) helix-helix complexes. It is based on computer simulations in membrane-like media and subsequent refinement/validation of the results using experimental studies of TM helix dimerization in a bacterial membrane by means of the ToxR system. The approach was applied to TM fragments of the ephrin receptor A1 (EphA1). A set of spatial structures of the dimer was proposed based on Monte Carlo simulations in an implicit membrane followed by molecular dynamics relaxation in an explicit lipid bilayer. The resulting models were employed for rational design of wild-type and mutant genetic constructions for ToxR assays. The computational and the experimental data are self-consistent and provide an unambiguous spatial model of the TM dimer of EphA1. The results of this work can be further used to develop new biologically active 'peptide interceptors' specifically targeting membrane domains of proteins.

    ID:312
  18. Polyansky A.A., Volynsky P.E., Arseniev A.S., Efremov R.G. (2009). Adaptation of a membrane-active peptide to heterogeneous environment. I. Structural plasticity of the peptide. The journal of physical chemistry. B 113 (4), 1107–19 [+]

    В статье приводится детальное описание различных факторов, определяющих процесс взаимодействия мембрано-активного пептида (неспецифический переносчик—пенетратин) с липидными бислоями разного состава. К ключевым факторам следует отнести: конформационную подвижность пептида, способность аминокислотных остатков образовывать специфические контакты с другими остатками пептида, а также полярными головками липидов.

    ID:125
  19. Polyansky A.A., Volynsky P.E., Arseniev A.S., Efremov R.G. (2009). Adaptation of a membrane-active peptide to heterogeneous environment. II. The role of mosaic nature of the membrane surface. The journal of physical chemistry. B 113 (4), 1120–6 [+]

    В статье постулируется мозаичная гидрофобно-гдрофильная организация поверхности липидной мембраны. Рассматривается влияние гетерогенности полярных свойств границы раздела вода-липиды на процесс связывания мембрано-активных агентов (на примере неспецифического пептидного переносчика — пенетратина).

    ID:126
  20. Bocharov E.V., Volynsky P.E., Pavlov K.V., Efremov R.G., Arseniev A.S. (2009). Structure elucidation of dimeric transmembrane domains of bitopic proteins. Cell Adh Migr 4 (2), 284–98 [+]

    The interaction between transmembrane helices is of great interest because it directly determines biological activity of a membrane protein. Either destroying or enhancing such interactions can result in many diseases related to dysfunction of different tissues in human body. One much studied form of membrane proteins known as bitopic protein is a dimer containing two membrane-spanning helices associating laterally. Establishing structure-function relationship as well as rational design of new types of drugs targeting membrane proteins requires precise structural information about this class of objects. At present time, to investigate spatial structure and internal dynamics of such transmembrane helical dimers, several strategies were developed based mainly on a combination of NMR spectroscopy, optical spectroscopy, protein engineering and molecular modeling. These approaches were successfully applied to homo- and heterodimeric transmembrane fragments of several bitopic proteins, which play important roles in normal and in pathological conditions of human organism.

    ID:1047
  21. Dubovskii P.V., Volynsky P.E., Polyansky A.A., Karpunin D.V., Chupin V.V., Efremov R.G., Arseniev A.S. (2008). Three-dimensional structure/hydrophobicity of latarcins specifies their mode of membrane activity. Biochemistry 47 (11), 3525–33 [+]

    Latarcins, linear peptides from the Lachesana tarabaevi spider venom, exhibit a broad-spectrum antimicrobial activity, likely acting on the bacterial cytoplasmic membrane. We study their spatial structures and interaction with model membranes by a combination of experimental and theoretical methods to reveal the structure-activity relationship. In this work, a 26 amino acid peptide, Ltc1, was investigated. Its spatial structure in detergent micelles was determined by (1)H nuclear magnetic resonance (NMR) and refined by Monte Carlo simulations in an implicit water-octanol slab. The Ltc1 molecule was found to form a straight uninterrupted amphiphilic helix comprising 8-23 residues. A dye-leakage fluorescent assay and (31)P NMR spectroscopy established that the peptide does not induce the release of fluorescent marker nor deteriorate the bilayer structure of the membranes. The voltage-clamp technique showed that Ltc1 induces the current fluctuations through planar membranes when the sign of the applied potential coincides with the one across the bacterial inner membrane. This implies that Ltc1 acts on the membranes via a specific mechanism, which is different from the carpet mode demonstrated by another latarcin, Ltc2a, featuring a helix-hinge-helix structure with a hydrophobicity gradient along the peptide chain. In contrast, the hydrophobic surface of the Ltc1 helix is narrow-shaped and extends with no gradient along the axis. We have also disclosed a number of peptides, structurally homologous to Ltc1 and exhibiting similar membrane activity. This indicates that the hydrophobic pattern of the Ltc1 helix and related antimicrobial peptides specifies their activity mechanism. The latter assumes the formation of variable-sized lesions, which depend upon the potential across the membrane.

    ID:315
  22. Bocharov E.V., Mineev K.S., Volynsky P.E., Ermolyuk Y.S., Tkach E.N., Sobol A.G., Chupin V.V., Kirpichnikov M.P., Efremov R.G., Arseniev A.S. (2008). Spatial structure of the dimeric transmembrane domain of the growth factor receptor ErbB2 presumably corresponding to the receptor active state. J. Biol. Chem. 283 (11), 6950–6 [+]

    Proper lateral dimerization of the transmembrane domains of receptor tyrosine kinases is required for biochemical signal transduction across the plasma membrane. The spatial structure of the dimeric transmembrane domain of the growth factor receptor ErbB2 embedded into lipid bicelles was obtained by solution NMR, followed by molecular dynamics relaxation in an explicit lipid bilayer. ErbB2 transmembrane segments associate in a right-handed alpha-helical bundle through the N-terminal tandem GG4-like motif Thr652-X3-Ser656-X3-Gly660, providing an explanation for the pathogenic power of some oncogenic mutations.

    ID:314
  23. Vereshaga Y.A., Volynsky P.E., Pustovalova J.E., Nolde D.E., Arseniev A.S., Efremov R.G. (2007). Specificity of helix packing in transmembrane dimer of the cell death factor BNIP3: a molecular modeling study. Proteins 69 (2), 309–25 [+]

    Предложен вычислительный метод предсказания пространственной структуры димеров трансмембранных альфа-спиралей. Подход основан на применении модели неявно заданной мембраны и конформационного поиска методом Монте-Карло в пространстве двугранных углов пептидов. Эффективность метода продемонстрирована на примере трансмембранного домена проапоптотического митохондриального белка BNIP3.

    ID:124
  24. Volynsky P.E., Bocharov E.V., Nolde D.E., Vereshaga Y.A., Mayzel M.L., Mineev K.S., Mineeva E.V., Pustovalova Yu.E., Gagnidze I.A., Efremov R.G., Arseniev A.S. (2006). Solution of the Spatial Structure of Dimeric Transmembrane Domains of Proteins by Heteronuclear NMR Spectroscopy and Molecular Modeling. Biophysics 51 (S1), S23–S27 [+]

    Membrane proteins play an important role in various biological processes. An approach combining
    NMR spectroscopy with molecular modeling was used to study the spatial structure and intramolecular dynamics of protein transmembrane domains consisting of two interacting α-helices. The approach was tested with model transmembrane domains and yielded detailed atomic-level data on the protein–protein and protein–lipid interactions.

    ID:347
  25. Polyansky A.A., Volynsky P.E., Nolde D.E., Arseniev A.S., Efremov R.G. (2005). Role of lipid charge in organization of water/lipid bilayer interface: insights via computer simulations. The journal of physical chemistry. B 109 (31), 15052–9 [+]

    Anionic unsaturated lipid bilayers represent suitable model systems that mimic real cell membranes: they are fluid and possess a negative surface charge. Understanding of detailed molecular organization of water-lipid interfaces in such systems may provide an important insight into the mechanisms of proteins' binding to membranes. Molecular dynamics (MD) of full-atom hydrated lipid bilayers is one of the most powerful tools to address this problem in silico. Unfortunately, wide application of computational methods for such systems is limited by serious technical problems. They are mainly related to correct treatment of long-range electrostatic effects. In this study a physically reliable model of an anionic unsaturated bilayer of 1,2-dioleoyl-sn-glycero-3-phosphoserine (DOPS) was elaborated and subjected to long-term MD simulations. Electrostatic interactions were treated with two different algorithms: spherical cutoff function and particle-mesh Ewald summation (PME). To understand the role of lipid charge in the system behavior, similar calculations were also carried out for zwitterionic bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). It was shown that, for the charged DOPS bilayer, the PME protocol performs much better than the cutoff scheme. In the last case a number of artifacts in the structural organization of the bilayer were observed. All of them were attributed to inadequate treatment of electrostatic interactions of lipid headgroups with counterions. Electrostatic properties, along with structural and dynamic parameters, of both lipid bilayers were investigated. Comparative analysis of the MD data reveals that the water-lipid interface of the DOPC bilayer is looser than that for DOPS. This makes possible deeper penetration of water molecules inside the zwitterionic (DOPC) bilayer, where they strongly interact with carbonyls of lipids. This can lead to thickening of the membrane interface in zwitterionic as compared to negatively charged bilayers.

    ID:843
  26. Dioubankova N.N., Malakhov A.D., Stetsenko D.A., Gait M.J., Volynsky P.E., Efremov R.G., Korshun V.A. (2003). Pyrenemethyl ara-uridine-2'-carbamate: a strong interstrand excimer in the major groove of a DNA duplex. Chembiochem 4 (9), 841–7 [+]

    The synthesis of new nucleoside derivatives, ara-uridine-2'-carbamates, and their incorporation into synthetic DNA oligomers is described. The modification directs ligands into the major groove of duplex DNA and somewhat destabilizes the duplexes of modified oligonucleotides with complementary DNA or RNA. In the case of pyrenemethyl carbamate modification in DNA-DNA duplexes, the destabilization is considerably reduced. The pyrenemethyl derivative also shows remarkable spectral properties: a "reversed" absorbance change for pyrene at 350 nm in the course of denaturation of the DNA duplex, as compared to the change seen in the nucleotide absorbance at 260 nm. This derivatization also causes pronounced sequence-dependent excimer formation in the major groove.

    ID:768