Беркут Антонина Анатольевна


Период обученияСтрана, городУчебное заведениеДополнительная информация
2006–2012 Россия, Москва Московский физико-технический институт

Избранные публикации

  1. Oparin P.B., Nadezhdin K.D., Berkut A.A., Arseniev A.S., Grishin E.V., Vassilevski A.A. (2016). Structure of purotoxin-2 from wolf spider: modular design and membrane-assisted mode of action in arachnid toxins. Biochem. J. 473 (19), 3113–26 [+]

    Traditionally, arachnid venoms are known to contain two particularly important groups of peptide toxins. One is disulfide-rich neurotoxins with a predominance of β-structure that specifically target protein receptors in neurons or muscle cells. The other is linear cationic cytotoxins that form amphiphilic α-helices and exhibit rather non-specific membrane-damaging activity. In the present paper, we describe the first 3D structure of a modular arachnid toxin, purotoxin-2 (PT2) from the wolf spider Alopecosa marikovskyi (Lycosidae), studied by NMR spectroscopy. PT2 is composed of an N-terminal inhibitor cystine knot (ICK, or knottin) β-structural domain and a C-terminal linear cationic domain. In aqueous solution, the C-terminal fragment is hyper-flexible, whereas the knottin domain is very rigid. In membrane-mimicking environment, the C-terminal domain assumes a stable amphipathic α-helix. This helix effectively tethers the toxin to membranes and serves as a membrane-access and membrane-anchoring device. Sequence analysis reveals that the knottin + α-helix architecture is quite widespread among arachnid toxins, and PT2 is therefore the founding member of a large family of polypeptides with similar structure motifs. Toxins from this family target different membrane receptors such as P2X in the case of PT2 and calcium channels, but their mechanism of action through membrane access may be strikingly similar.

  2. Berkut A.A., Peigneur S., Myshkin M.Y., Paramonov A.S., Lyukmanova E.N., Arseniev A.S., Grishin E.V., Tytgat J., Shenkarev Z.O., Vassilevski A.A. (2015). Structure of Membrane-active Toxin from Crab Spider Heriaeus melloteei Suggests Parallel Evolution of Sodium Channel Gating Modifiers in Araneomorphae and Mygalomorphae. J. Biol. Chem. 290 (1), 492–504 [+]

    We present a structural and functional study of a sodium channel activation inhibitor from crab spider venom. Hm-3 is an insecticidal peptide toxin consisting of 35 amino acid residues from the spider Heriaeus melloteei (Thomisidae). We produced Hm-3 recombinantly in Escherichia coli and determined its structure by NMR spectroscopy. Typical for spider toxins, Hm-3 was found to adopt the so-called "inhibitor cystine knot" or "knottin" fold stabilized by three disulfide bonds. Its molecule is amphiphilic with a hydrophobic ridge on the surface enriched in aromatic residues and surrounded by positive charges. Correspondingly, Hm-3 binds to both neutral and negatively charged lipid vesicles. Electrophysiological studies showed that at a concentration of 1 μm Hm-3 effectively inhibited a number of mammalian and insect sodium channels. Importantly, Hm-3 shifted the dependence of channel activation to more positive voltages. Moreover, the inhibition was voltage-dependent, and strong depolarizing prepulses attenuated Hm-3 activity. The toxin is therefore concluded to represent the first sodium channel gating modifier from an araneomorph spider and features a "membrane access" mechanism of action. Its amino acid sequence and position of the hydrophobic cluster are notably different from other known gating modifiers from spider venom, all of which are described from mygalomorph species. We hypothesize parallel evolution of inhibitor cystine knot toxins from Araneomorphae and Mygalomorphae suborders.

  3. Berkut A.A., Usmanova D.R., Peigneur S., Oparin P.B., Mineev K.S., Odintsova T.I., Tytgat J., Arseniev A.S., Grishin E.V., Vassilevski A.A. (2014). Structural similarity between defense peptide from wheat and scorpion neurotoxin permits rational functional design. J. Biol. Chem. 289 (20), 14331–40 [+]

    In this study, we present the spatial structure of the wheat antimicrobial peptide (AMP) Tk-AMP-X2 studied using NMR spectroscopy. This peptide was found to adopt a disulfide-stabilized α-helical hairpin fold and therefore belongs to the α-hairpinin family of plant defense peptides. Based on Tk-AMP-X2 structural similarity to cone snail and scorpion potassium channel blockers, a mutant molecule, Tk-hefu, was engineered by incorporating the functionally important residues from κ-hefutoxin 1 onto the Tk-AMP-X2 scaffold. The designed peptide contained the so-called essential dyad of amino acid residues significant for channel-blocking activity. Electrophysiological studies showed that although the parent peptide Tk-AMP-X2 did not present any activity against potassium channels, Tk-hefu blocked Kv1.3 channels with similar potency (IC50 ∼ 35 μm) to κ-hefutoxin 1 (IC50 ∼ 40 μm). We conclude that α-hairpinins are attractive in their simplicity as structural templates, which may be used for functional engineering and drug design.

  4. Slavokhotova A.A., Rogozhin E.A., Musolyamov A.K., Andreev Y.A., Oparin P.B., Berkut A.A., Vassilevski A.A., Egorov T.A., Grishin E.V., Odintsova T.I. (2014). Novel antifungal α-hairpinin peptide from Stellaria media seeds: structure, biosynthesis, gene structure and evolution. Plant Mol. Biol. 84 (1-2), 189–202 [+]

    Plant defense against disease is a complex multistage system involving initial recognition of the invading pathogen, signal transduction and activation of specialized genes. An important role in pathogen deterrence belongs to so-called plant defense peptides, small polypeptide molecules that present antimicrobial properties. Using multidimensional liquid chromatography, we isolated a novel antifungal peptide named Sm-AMP-X (33 residues) from the common chickweed (Stellaria media) seeds. The peptide sequence shows no homology to any previously described proteins. The peculiar cysteine arrangement (C(1)X3C(2)XnC(3)X3C(4)), however, allocates Sm-AMP-X to the recently acknowledged α-hairpinin family of plant defense peptides that share the helix-loop-helix fold stabilized by two disulfide bridges C(1)-C(4) and C(2)-C(3). Sm-AMP-X exhibits high broad-spectrum activity against fungal phytopathogens. We further showed that the N- and C-terminal "tail" regions of the peptide are important for both its structure and activity. The truncated variants Sm-AMP-X1 with both disulfide bonds preserved and Sm-AMP-X2 with only the internal S-S-bond left were progressively less active against fungi and presented largely disordered structure as opposed to the predominantly helical conformation of the full-length antifungal peptide. cDNA and gene cloning revealed that Sm-AMP-X is processed from a unique multimodular precursor protein that contains as many as 12 tandem repeats of α-hairpinin-like peptides. Structure of the sm-amp-x gene and two related pseudogenes sm-amp-x-ψ1 and sm-amp-x-ψ2 allows tracing the evolutionary scenario that led to generation of such a sophisticated precursor protein. Sm-AMP-X is a new promising candidate for engineering disease resistance in plants.

  5. Chugunov A.O., Koromyslova A.D., Berkut A.A., Peigneur S., Tytgat J., Polyansky A.A., Pentkovsky V.M., Vassilevski A.A., Grishin E.V., Efremov R.G. (2013). Modular Organization of α-Toxins from Scorpion Venom Mirrors Domain Structure of Their Targets, Sodium Channels. J. Biol. Chem. 288 (26), 19014–27 [+]

    To gain success in the evolutionary "arms race," venomous animals such as scorpions produce diverse neurotoxins selected to hit targets in the nervous system of prey. Scorpion α-toxins affect insect and/or mammalian voltage-gated sodium channels (Navs) and thereby modify the excitability of muscle and nerve cells. Although more than 100 α-toxins are known and a number of them have been studied into detail, the molecular mechanism of their interaction with Navs is still poorly understood. Here, we employ extensive molecular dynamics simulations and spatial mapping of hydrophobic/hydrophilic properties distributed over the molecular surface of α-toxins. It is revealed that despite the small size and relatively rigid structure, these toxins possess modular organization from structural, functional, and evolutionary perspectives. The more conserved and rigid "core module" is supplemented with the "specificity module" (SM) that is comparatively flexible and variable and determines the taxon (mammal versus insect) specificity of α-toxin activity. We further show that SMs in mammal toxins are more flexible and hydrophilic than in insect toxins. Concomitant sequence-based analysis of the extracellular loops of Navs suggests that α-toxins recognize the channels using both modules. We propose that the core module binds to the voltage-sensing domain IV, whereas the more versatile SM interacts with the pore domain in repeat I of Navs. These findings corroborate and expand the hypothesis on different functional epitopes of toxins that has been reported previously. In effect, we propose that the modular structure in toxins evolved to match the domain architecture of Navs.