Барсуков Леонид Иванович

Избранные публикации

  1. Sychev S.V., Balandin S.V., Panteleev P.V., Barsukov L.I., Ovchinnikova T.V. (2015). Lipid-dependent pore formation by antimicrobial peptides arenicin-2 and melittin demonstrated by their proton transfer activity. J. Pept. Sci. 21 (2), 71–6 [+]

    This work presents a comparative study of proton transfer activity (PTA) of two cationic (+6) antimicrobial peptides, β-structural arenicin-2 and α-helical melittin. A new approach was proposed for the detection of passive proton transfer by using proteoliposomes containing bacteriorhodopsin, which creates a small light-induced electrochemical proton gradient ∆ΔpH. Addition of several nanomoles of the peptides lowers ∆ΔpH that is proximately indicative of the pore formation. The quantitative analysis of sigmoidal dependences of ∆pH on the peptides concentration was carried out using liposomes prepared from PC, PC/PE, PC/PE/PI and PC/PG. Substitution of PC-containing liposomes with PE-containing ones, having negative spontaneous curvature, reduced the PTA of α-helical melittin and increased that of β-structural arenicin-2. This result indicates an essential difference in the pore formation by these peptides. Further increase of PTA in response to arenicin-2 (in contrast to melittin) was observed in the liposomes prepared from PC/PE/PI. The data analysis leads to the conclusion that PTA is influenced by (i) efficiency of the pore assemblage, which depends on the structure of pore-forming peptides, and the spontaneous curvature of lipids and (ii) the presence of mobile protons in the polar head groups of phospholipids.

  2. Shenkarev Z.O., Balandin S.V., Trunov K.I., Paramonov A.S., Sukhanov S.V., Barsukov L.I., Arseniev A.S., Ovchinnikova T.V. (2011). Molecular mechanism of action of β-hairpin antimicrobial peptide arenicin: oligomeric structure in dodecylphosphocholine micelles and pore formation in planar lipid bilayers. Biochemistry 50 (28), 6255–65 [+]

    The membrane-active, cationic, β-hairpin peptide, arenicin, isolated from marine polychaeta Arenicola marina exhibits a broad spectrum of antimicrobial activity. The peptide in aqueous solution adopts the significantly twisted β-hairpin conformation without pronounced amphipathicity. To assess the mechanism of arenicin action, the spatial structure and backbone dynamics of the peptide in membrane-mimicking media and its pore-forming activity in planar lipid bilayers were studied. The spatial structure of the asymmetric arenicin dimer stabilized by parallel association of N-terminal strands of two β-hairpins was determined using triple-resonance nuclear magnetic resonance (NMR) spectroscopy in dodecylphosphocholine (DPC) micelles. Interaction of arenicin with micelles and its oligomerization significantly decreased the right-handed twist of the β-hairpin, increased its amphipathicity, and led to stabilization of the peptide backbone on a picosecond to nanosecond time scale. Relaxation enhancement induced by water-soluble (Mn(2+)) and lipid-soluble (16-doxylstearate) paramagnetic probes pointed to the dimer transmembrane arrangement. Qualitative NMR and circular dichroism study of arenicin-2 in mixed DPC/1,2-dioleoyl-sn-glycero-3-phosphoglycerol bicelles, sodium dodecyl sulfate micelles, and lipid vesicles confirmed that a similar dimeric assembly of the peptide was retained in membrane-mimicking systems containing negatively charged lipids and detergents. Arenicin-induced conductance was dependent on the lipid composition of the membrane. Arenicin low-conductivity pores were detected in the phosphatidylethanolamine-containing lipid mixture, whereas the high-conductivity pores were observed in an exclusively anionic lipid system. The measured conductivity levels agreed with the model in which arenicin antimicrobial activity was mediated by the formation of toroidal pores assembled of two, three, or four β-structural peptide dimers and lipid molecules. The structural transitions involved in arenicin membrane-disruptive action are discussed.

  3. Bystrov V.F., Dubrovina N.I., Barsukov L.I., Bergelson L.D. (1971). NMR differentiation of the internal and external phospholipid membrane surfaces using paramagnetic Mn2+ and Eu3+ ions. Chem. Phys. Lipids 6 (4), 343–350 [+]

    The effect of paramagnetic Mn2+ and Eu3+ ions on the NMR spectra of sonicated lecithin dispersions in water and benzene has been investigated. In aqueous dispersions containing paramagnetic ions the N+(CH3)3 signal of the lecithin molecules in the lipid bilayer consists of two components, one broadened by Mn2+ and shifted to high field by Eu3+ must correspond to molecules in the external surface in contact with the bulk salt solution, and the other corresponding to internal lecithin molecules in contact with the ion free internal aqueous phase. Thus the external and internal surfaces of a lecithin containing membrane can be discriminated. The rates of exchange of the paramagnetic ions, of the lecithin and the water molecules between micelles and/or between micelles and external medium have been evaluated.

  4. Шемякин М.М., Бергельсон Л.Д., Барсуков Л.И., Вавер В.А. (1963). Стереохимия и механизм реакции Виттига. Известия АН СССР. ОХН. 6, 1053–1063 [+]

    Сетерохимия реакции Виттига до сих пор не изучалась. Нами было предпринято систематическое изучение влияния различных внешних факторов на стерическую направленность реакции Виттига, так как так как выяснение условий избирательного получения цис- и транс-изомеров могло бы иметь существенное значение для синтеза в дальнейшем многих типов синтеза природных веществ.