Laboratory of neuroreceptors and neuroregulators

Department of Molecular Neurobiology

Head: Sergey Kozlov, D.Sc
serg@ibch.ru+7(495)336 4022

Toxinology, neurotoxins, ionotropic receptors, protein structure, recombinant polypeptides, bioactive molecules for medicine

The laboratory conducts research of biologically active components from natural sources, interacting with a variety of targets in the cell membrane, as well as developing a common approach for the identification, isolation, structural and functional analysis and use as a thin tool which modulate the activity of the nerve cells membrane receptors. Laboratory research allows to be closer to an understanding the molecular mechanisms of the natural ligand specificity action and lays the foundation for the development of fundamentally new highly specific drugs and insecticides.

The laboratory cooperates with The Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, (Magazanik L.G.), Federal Scientific Clinical Center of Physical-Chemical Medicine (Govorun V.M.), Sadykov Institute of Bioorganic Chemistry of the Academy of Sciences of Uzbekistan (Salikhov S.I.), Vavilov Institute of General Genetics RAS (Odintsova T.I., PhD), All-Russian Research Institute of Agricultural Biotechnology (prof. Babakov A.V.), University of Leuven, Belgium (Prof. Tytgat J.).

The laboratory has also performed studies in cooperation with Monsanto, Bayer, Zeneka, DuPont and other companies.

Young people are always welcome and get first class practical courses. Since its foundation, 23 PhD dissertations have been successfully defended in the Laboratory. High quality equipment, use of state-of-the-art methods, ongoing staff practical skill training, open-mindedness and ambitious scientific goals – this is what best describes the Laboratory today.

The Laboratory was founded in 1987 by Professor Eugene V. Grishin, member of the Russian Academy of Sciences. The laboratory has evolved into a world-leading scientific team studying natural neurotoxins and their neuronal receptors. The focus is on toxic components of animal venoms acting on different targets in the cell membrane. General approaches have been elaborated to active venom components identification, isolation, structure-function analyses and use as high-precision tools modulating neural membrane receptor activity.

  • Search and investigation of polypeptide toxins and lower-modulated compounds that modulate activity of membrane receptors involved in processes of generation and pain signaling (Korolkova Y.V., PhD; Andreev Ya.A., PhD; Koshelev S.G., PhD)
  • Studies of antimicrobial peptides from arthropods and plant defense peptides (Rogozhin E.A., PhD)
  • Production of recombinant polypeptide toxins (Andreev Ya.A. PhD); study of DNA complex nanostructure (Danilevich V.N.).
  • Development of agricultural crop protection methods to increase crop (Rogozhin E.)
  • Development of methods for the production of recombinant polypeptide toxins in various heterologous expression systems (Yaroslav A. Andreev, Catherine E. Maleeva)
  • Omixed technologies implementation in search and structural identification of biologically active compounds of complex multi-component mixtures (Mikov A.)
  • Creation of cell lines for the analysis of ligand-receptor interactions (Julia Korol'kova, Yaroslav A. Andreev)
  • Studying the DNA nanostructure complexes (Vasiliy Danilevich)
  • a new class of toxins such as spiders argiope – polyamine blocker of glutamate receptors (Grishin et al., 1983)
  • a family of high-selective neurotoxins from the venom of the Black Widow ("black widow") – latrotoxin (Kiyatkin et al., 1990)
  • membrane-active peptides from the venom of ants and spiders (Kozlov et al., 2006)
  • polypeptide toxins specific for sodium, potassium, calcium, proton-sensitive, TRPV1, TRPA1-channels.
  • low-molecular weight biologically active compounds from medicinal plants with analgesic effect.
  • In the study of neuronal receptors isolated and characterized for the first time all of the individual components of the mammalian sodium channel electro-excitability membranes.
NamePositionContacts
Anna Slavokhotova
Sergey Kozlov, D.Scdepart. dir.serg@ibch.ru+7(495)336 4022
Yaroslav Andreev, Ph.D.s. r. f.ay@land.ru+7(495)336-40-20
Vasilij Danilevich, Ph.D.s. r. f.dan@mx.ibch.ru+7(495)336-40-22
Elena Eljakova, Ph.D.s. r. f.elyakova@yandex.ru+7(495)429-87-20
Yulija Korol'kova, Ph.D.s. r. f.july@ibch.ru+7(495)3366540
Sergej Koshelev, Ph.D.s. r. f.sknew@yandex.ru+7(495)3306683
Evgenij Rogozhinr. f.rea21@list.ru+7(495)336-40-22
Dmitry Osmakovr. f.
Alexander Mikovj. r. f.mikov.alexander@gmail.com+7(495)3366540
Ekaterina Maleevaj. r. f.+7()3364022
Irina Mosharovaj. r. f.+7()3306683
Yulia Logashinaj. r. f.julek022@rambler.ru
Ljudmila Aleksandrovaeng.+7(495)336-40-22
Ksenia Lybovaeng.
Anna Emelianovares. eng.annaemelyan@gmail.com

Former members:

Tseziy Egorov, D.Scl. r. f.ego@ibch.ru
Alexander Vassilevski, Ph.D.s. r. f.avas@ibch.ru
Tat'jana Valjakina, Ph.D.s. r. f.valyakina@ibch.ru
Kirill Pluzhnikov, Ph.D.s. r. f.
Maria Simonova, Ph.D.r. f.simonova@ibch.ru
Ravilja Komalevar. f.
Ol'ga Lahtinar. f.
Elena Petrova, Ph.D.r. f.petrova@ibch.ru
Aleksandr Musoljamovj. r. f.musolyamov@ibch.ru
Larisa Samohvalovaj. r. f.
A Astafevaj. r. f.a_sanya@mail.ru
Maria Sachkova, Ph.D.PhD stud.sachkovamasha@mail.ru
Alexander Arzamasovstud.Alex_arzamasov@hotmail.com
Zhanna Kanaevskayalab. as.zh-kanewskaya@yandex.ru
Evgeny Grishin, member of the academy of sciencesdept. head

Selected publications

  1. Babenko V.V., Mikov A.N., Manuvera V.A., Anikanov N.A., Kovalchuk S.I., Andreev Y.A., Logashina Y.A., Kornilov D.A., Manolov A.I., Sanamyan N.P., Sanamyan K.E., Kostryukova E.S., Kozlov S.A., Grishin E.V., Govorun V.M., Lazarev V.N. (2017). Identification of unusual peptides with new Cys frameworks in the venom of the cold-water sea anemone Cnidopus japonicus. Sci Rep 7 (1), 14534 [+]

    Sea anemones (Actiniaria) are intensely popular objects of study in venomics. Order Actiniaria includes more than 1,000 species, thus presenting almost unlimited opportunities for the discovery of novel biologically active molecules. The venoms of cold-water sea anemones are studied far less than the venoms of tropical sea anemones. In this work, we analysed the molecular venom composition of the cold-water sea anemone Cnidopus japonicus. Two sets of NGS data from two species revealed molecules belonging to a variety of structural classes, including neurotoxins, toxin-like molecules, linear polypeptides (Cys-free), enzymes, and cytolytics. High-throughput proteomic analyses identified 27 compounds that were present in the venoms. Some of the toxin-like polypeptides exhibited novel Cys frameworks. To characterise their function in the venom, we heterologously expressed 3 polypeptides with unusual Cys frameworks (designated CjTL7, CjTL8, and AnmTx Cj 1c-1) in E. coli. Toxicity tests revealed that the CjTL8 polypeptide displays strong crustacean-specific toxicity, while AnmTx Cj 1c-1 is toxic to both crustaceans and insects. Thus, an improved NGS data analysis algorithm assisted in the identification of toxins with unusual Cys frameworks showing no homology according to BLAST. Our study shows the advantage of combining omics analysis with functional tests for active polypeptide discovery.

    ID:1908
  2. Logashina Y.A., Solstad R.G., Mineev K.S., Korolkova Y.V., Mosharova I.V., Dyachenko I.A., Palikov V.A., Palikova Y.A., Murashev A.N., Arseniev A.S., Kozlov S.A., Stensvåg K., Haug T., Andreev Y.A. (2017). New Disulfide-Stabilized Fold Provides Sea Anemone Peptide to Exhibit Both Antimicrobial and TRPA1 Potentiating Properties. Toxins (Basel) 9 (5), [+]

    A novel bioactive peptide named τ-AnmTx Ueq 12-1 (short name Ueq 12-1) was isolated and characterized from the sea anemone Urticina eques. Ueq 12-1 is unique among the variety of known sea anemone peptides in terms of its primary and spatial structure. It consists of 45 amino acids including 10 cysteine residues with an unusual distribution and represents a new group of sea anemone peptides. The 3D structure of Ueq 12-1, determined by NMR spectroscopy, represents a new disulfide-stabilized fold partly similar to the defensin-like fold. Ueq 12-1 showed the dual activity of both a moderate antibacterial activity against Gram-positive bacteria and a potentiating activity on the transient receptor potential ankyrin 1 (TRPA1). Ueq 12-1 is a unique peptide potentiator of the TRPA1 receptor that produces analgesic and anti-inflammatory effects in vivo. The antinociceptive properties allow us to consider Ueq 12-1 as a potential analgesic drug lead with antibacterial properties.

    ID:1914
  3. Nekrasova O.V., Volyntseva A.D., Kudryashova K.S., Novoseletsky V.N., Lyapina E.A., Illarionova A.V., Yakimov S.A., Korolkova Y.V., Shaitan K.V., Kirpichnikov M.P., Feofanov A.V. (2016). Complexes of Peptide Blockers with Kv1.6 Pore Domain: Molecular Modeling and Studies with KcsA-Kv1.6 Channel. J Neuroimmune Pharmacol , [+]

    Potassium voltage-gated Kv1.6 channel, which is distributed primarily in neurons of central and peripheral nervous systems, is of significant physiological importance. To date, several high-affinity Kv1.6-channel blockers are known, but the lack of selective ones among them hampers the studies of tissue localization and functioning of Kv1.6 channels. Here we present an approach to advanced understanding of interactions of peptide toxin blockers with a Kv1.6 pore. It combines molecular modeling studies and an application of a new bioengineering system based on a KcsA-Kv1.6 hybrid channel for the quantitative fluorescent analysis of blocker-channel interactions. Using this system we demonstrate that peptide toxins agitoxin 2, kaliotoxin1 and OSK1 have similar high affinity to the extracellular vestibule of the K(+)-conducting pore of Kv1.6, hetlaxin is a low-affinity ligand, whereas margatoxin and scyllatoxin do not bind to Kv1.6 pore. Binding of toxins to Kv1.6 pore has considerable inverse dependence on the ionic strength. Model structures of KcsA-Kv1.6 and Kv1.6 complexes with agitoxin 2, kaliotoxin 1 and OSK1 were obtained using homology modeling and molecular dynamics simulation. Interaction interfaces, which are formed by 15-19 toxin residues and 10 channel residues, are described and compared. Specific sites of Kv1.6 pore recognition are identified for targeting of peptide blockers. Analysis of interactions between agitoxin 2 derivatives with point mutations (S7K, S11G, L19S, R31G) and KcsA-Kv1.6 confirms reliability of the calculated complex structure.

    ID:1611
  4. Osmakov D.I., Koshelev S.G., Andreev Y.A., Dyachenko I.A., Bondarenko D.A., Murashev A.N., Grishin E.V., Kozlov S.A. (2015). Conversed mutagenesis of an inactive peptide to ASIC3 inhibitor for active sites determination. Toxicon , [+]

    Peptide Ugr9-1 from the venom of sea anemone Urticina grebelnyi selectively inhibits the ASIC3 channel and significantly reverses inflammatory and acid-induced pain in vivo. A close homolog peptide Ugr 9-2 does not have these features. To find the pharmacophore residues and explore structure-activity relationships of Ugr 9-1, we performed site-directed mutagenesis of Ugr 9-2 and replaced several positions by the corresponding residues from Ugr 9-1. Mutant peptides Ugr 9-2 T9F and Ugr 9-2 Y12H were able to inhibit currents of the ASIC3 channels 2.2 times and 1.3 times weaker than Ugr 9-1, respectively. Detailed analysis of the spatial models of Ugr 9-1, Ugr 9-2 and both mutant peptides revealed the presence of the basic-aromatic clusters on opposite sides of the molecule, each of which is responsible for the activity. Additionally, Ugr9-1 mutant with truncated N- and C-termini retained similar with the Ugr9-1 action in vitro and was equally potent in vivo model of thermal hypersensitivity. All together, these results are important for studying the structure-activity relationships of ligand-receptor interaction and for the future development of peptide drugs from animal toxins.

    ID:1472
  5. Dubovskii P.V., Vassilevski A.A., Kozlov S.A., Feofanov A.V., Grishin E.V., Efremov R.G. (2015). Latarcins: versatile spider venom peptides. Cell. Mol. Life Sci. 72 (23), 4501–22 [+]

    Arthropod venoms feature the presence of cytolytic peptides believed to act synergetically with neurotoxins to paralyze prey or deter aggressors. Many of them are linear, i.e., lack disulfide bonds. When isolated from the venom, or obtained by other means, these peptides exhibit common properties. They are cationic; being mostly disordered in aqueous solution, assume amphiphilic α-helical structure in contact with lipid membranes; and exhibit general cytotoxicity, including antifungal, antimicrobial, hemolytic, and anticancer activities. To suit the pharmacological needs, the activity spectrum of these peptides should be modified by rational engineering. As an example, we provide a detailed review on latarcins (Ltc), linear cytolytic peptides from Lachesana tarabaevi spider venom. Diverse experimental and computational techniques were used to investigate the spatial structure of Ltc in membrane-mimicking environments and their effects on model lipid bilayers. The antibacterial activity of Ltc was studied against a panel of Gram-negative and Gram-positive bacteria. In addition, the action of Ltc on erythrocytes and cancer cells was investigated in detail with confocal laser scanning microscopy. In the present review, we give a critical account of the progress in the research of Ltc. We explore the relationship between Ltc structure and their biological activity and derive molecular characteristics, which can be used for optimization of other linear peptides. Current applications of Ltc and prospective use of similar membrane-active peptides are outlined.

    ID:1395
  6. Astafieva A.A., Enyenihi A.A., Rogozhin E.A., Kozlov S.A., Grishin E.V., Odintsova T.I., Zubarev R.A., Egorov T.A. (2015). Novel proline-hydroxyproline glycopeptides from the dandelion (Taraxacum officinale Wigg.) flowers: de novo sequencing and biological activity. Plant Sci. 238, 323–9 [+]

    Two novel homologous peptides named ToHyp1 and ToHyp2 that show no similarity to any known proteins were isolated from Taraxacum officinale Wigg. flowers by multidimensional liquid chromatography. Amino acid and mass spectrometry analyses demonstrated that the peptides have unusual structure: they are cysteine-free, proline-hydroxyproline-rich and post-translationally glycosylated by pentoses, with 5 carbohydrates in ToHyp2 and 10 in ToHyp1. The ToHyp2 peptide with a monoisotopic molecular mass of 4350.3Da was completely sequenced by a combination of Edman degradation and de novo sequencing via top down multistage collision induced dissociation (CID) and higher energy dissociation (HCD) tandem mass spectrometry (MS(n)). ToHyp2 consists of 35 amino acids, contains eighteen proline residues, of which 8 prolines are hydroxylated. The peptide displays antifungal activity and inhibits growth of Gram-positive and Gram-negative bacteria. We further showed that carbohydrate moieties have no significant impact on the peptide structure, but are important for antifungal activity although not absolutely necessary. The deglycosylated ToHyp2 peptide was less active against the susceptible fungus Bipolaris sorokiniana than the native peptide. Unique structural features of the ToHyp2 peptide place it into a new family of plant defense peptides. The discovery of ToHyp peptides in T. officinale flowers expands the repertoire of molecules of plant origin with practical applications.

    ID:1474
  7. Mikov A.N., Fedorova I.M., Potapieva N.N., Maleeva E.E., Andreev Y.A., Zaitsev A.V., Kim K.K., Bocharov E.V., Bozin T.N., Altukhov D.A., Lipkin A.V., Kozlov S.A., Tikhonov D.B., Grishin E.V. (2015). ω-Tbo-IT1-New Inhibitor of Insect Calcium Channels Isolated from Spider Venom. Sci Rep 5, 17232 [+]

    Novel disulfide-containing polypeptide toxin was discovered in the venom of the Tibellus oblongus spider. We report on isolation, spatial structure determination and electrophysiological characterization of this 41-residue toxin, called ω-Tbo-IT1. It has an insect-toxic effect with LD50 19 μg/g in experiments on house fly Musca domestica larvae and with LD50 20 μg/g on juvenile Gromphadorhina portentosa cockroaches. Electrophysiological experiments revealed a reversible inhibition of evoked excitatory postsynaptic currents in blow fly Calliphora vicina neuromuscular junctions, while parameters of spontaneous ones were not affected. The inhibition was concentration dependent, with IC50 value 40 ± 10 nM and Hill coefficient 3.4 ± 0.3. The toxin did not affect frog neuromuscular junctions or glutamatergic and GABAergic transmission in rat brains. Ca(2+) currents in Calliphora vicina muscle were not inhibited, whereas in Periplaneta americana cockroach neurons at least one type of voltage gated Ca(2+) current was inhibited by ω-Tbo-IT1. Thus, the toxin apparently acts as an inhibitor of presynaptic insect Ca(2+) channels. Spatial structure analysis of the recombinant ω-Tbo-IT1 by NMR spectroscopy in aqueous solution revealed that the toxin comprises the conventional ICK fold containing an extended β-hairpin loop and short β-hairpin loop which are capable of making "scissors-like mutual motions".

    ID:1341
  8. Pluzhnikov K.A., Kozlov S.A., Vassilevski A.A., Vorontsova O.V., Feofanov A.V., Grishin E.V. (2014). Linear antimicrobial peptides from Ectatomma quadridens ant venom. Biochimie 107 Pt B, 211–5 [+]

    Venoms from three poneromorph ant species (Paraponera clavata, Ectatomma quadridens and Ectatomma tuberculatum) were investigated for the growth inhibition of Gram-positive and Gram-negative bacteria. It was shown that the venom of E. quadridens and its peptide fraction in particular possess marked antibacterial action. Three linear antimicrobial peptides sharing low similarity to the well-known ponericin peptides were isolated from this ant venom by means of size-exclusion and reversed-phase chromatography. The peptides showed antimicrobial activity at low micromolar concentrations. Their primary structure was established by direct Edman sequencing in combination with mass spectrometry. The most active peptide designated ponericin-Q42 was chemically synthesized. Its secondary structure was investigated in aqueous and membrane-mimicking environment, and the peptide was shown to be partially helical already in water, which is unusual for short linear peptides. Analysis of its activity on different bacterial strains, human erythrocytes and chronic myelogenous leukemia K562 cells revealed that the peptide shows broad spectrum cytolytic activity at micromolar and submicromolar concentrations. Ponericin-Q42 also possesses weak toxic activity on flesh fly larvae with LD50 of ∼105 μg/g.

    ID:1150
  9. Osmakov D.I., Kozlov S.A., Andreev Y.A., Koshelev S.G., Sanamyan N.P., Sanamyan K.E., Dyachenko I.A., Bondarenko D.A., Murashev A.N., Mineev K.S., Arseniev A.S., Grishin E.V. (2013). Sea Anemone Peptide with Uncommon β-Hairpin Structure Inhibits Acid-sensing Ion Channel 3 (ASIC3) and Reveals Analgesic Activity. J. Biol. Chem. 288 (32), 23116–27 [+]

    Three novel peptides were isolated from the venom of the sea anemone Urticina grebelnyi. All of them are 29 amino acid peptides cross-linked by two disulfide bridges, with a primary structure similar to other sea anemone peptides belonging to structural group 9a. The structure of the gene encoding the shared precursor protein of the identified peptides was determined. One peptide, π-AnmTX Ugr 9a-1 (short name Ugr 9-1), produced a reversible inhibition effect on both the transient and the sustained current of human ASIC3 channels expressed in Xenopus laevis oocytes. It completely blocked the transient component (IC50 10 ± 0.6 μm) and partially (48 ± 2%) inhibited the amplitude of the sustained component (IC50 1.44 ± 0.19 μm). Using in vivo tests in mice, Ugr 9-1 significantly reversed inflammatory and acid-induced pain. The other two novel peptides, AnmTX Ugr 9a-2 (Ugr 9-2) and AnmTX Ugr 9a-3 (Ugr 9-3), did not inhibit the ASIC3 current. NMR spectroscopy revealed that Ugr 9-1 has an uncommon spatial structure, stabilized by two S-S bridges, with three classical β-turns and twisted β-hairpin without interstrand disulfide bonds. This is a novel peptide spatial structure that we propose to name boundless β-hairpin.

    ID:864
  10. Kabanova N.V., Vassilevski A.A., Rogachevskaja O.A., Bystrova M.F., Korolkova Y.V., Pluzhnikov K.A., Romanov R.A., Grishin E.V., Kolesnikov S.S. (2012). Modulation of P2X3 receptors by spider toxins. Biochim. Biophys. Acta 1818 (11), 2868–2875 [+]

    Recently, the novel peptide named purotoxin-1 (PT1) has been identified in the venom of the spider Geolycosa sp. and shown to exert marked modulatory effects on P2X3 receptors in rat sensory neurons. Here we studied another polypeptide from the same spider venom, purotoxin-2 (PT2), and demonstrated that it also affected activity of mammalian P2X3 receptors. The murine and human P2X3 receptors were heterologously expressed in cells of the CHO line, and nucleotide-gated currents were stimulated by CTP and ATP, respectively. Both PT1 and PT2 negligibly affected P2X3-mediated currents elicited by brief pulses of the particular nucleotide. When subthreshold CTP or ATP was added to the bath to exert the high-affinity desensitization of P2X3 receptors, both spider toxins strongly enhanced the desensitizing action of the ambient nucleotides. At the concentration of 50nM, PT1 and PT2 elicited 3-4-fold decrease in the IC(50) dose of ambient CTP or ATP. In contrast, 100nM PT1 and PT2 negligibly affected nucleotide-gated currents mediated by mP2X2 receptors or mP2X2/mP2X3 heteromers. Altogether, our data point out that the PT1 and PT2 toxins specifically target the fast-desensitizing P2X3 receptor, thus representing a unique tool to manipulate its activity.

    ID:730
  11. Andreev Y.A., Kozlov S.A., Koshelev S.G., Ivanova E.A., Monastyrnaya M.M., Kozlovskaya E.P., Grishin E.V. (2008). Analgesic compound from sea anemone Heteractis crispa is the first polypeptide inhibitor of vanilloid receptor 1 (TRPV1). J. Biol. Chem. 283 (35), 23914–21 [+]

    The first inhibitor of thermoreceptors TRPV1 that play an important role in inflammation and pain sensation was isolated from nematocyst extract of the sea anemone Heteractis crispa. Recombinant analogue of the peptide named APHC1 was found to exert high analgesic activity comparable to that of opioids in vivo. Unlike opioids, however, the action of APHC1 does not lead to a narcotic effect. The newly described polypeptide has great practical value in terms of new analgesic and anti-inflammatory drug production.

    ID:87
  12. Kozlov S.A., Vassilevski A.A., Feofanov A.V., Surovoy A.Y., Karpunin D.V., Grishin E.V. (2006). Latarcins, antimicrobial and cytolytic peptides from the venom of the spider Lachesana tarabaevi (Zodariidae) that exemplify biomolecular diversity. J. Biol. Chem. 281 (30), 20983–92 [+]

    A family of short linear polypeptide molecules, latarcins, was found in the venom of the spider Lachesana tarabaevi. Some peptides were chemically synthesized and their antimicrobial properties were studied. The bactericidal activity of latarcins matched that of the most active known antimicrobial peptides from different animals. The high therapeutic potential of these structurally simple polypeptide molecules will be brought to clinic in the near future.

    ID:86
  13. Kozlov S., Malyavka A., McCutchen B., Lu A., Schepers E., Herrmann R., Grishin E. (2005). A novel strategy for the identification of toxinlike structures in spider venom. Proteins 59 (1), 131–40 [+]

    We compared two different approaches to sequence information analysis from the expressed sequence tag (EST) library constructed for the venom glands of the spider Agelena orientalis. Some results were more illustrative and reliable by the contig analysis technique, whereas our novel method, with specific structural markers introduced for protein structure detection, allowed us to overcome some limitations of the contig analysis. A novel technique was suggested for the identification in data banks of the spider's ion channel inhibitor toxins using primary structure features common to all spiders. Analysis of about 150 polypeptides made it possible to introduce 3 primary structure motifs for spider toxins: the Principal Structural Motif (PSM), which postulates the existence of 6 amino acid residues between the first and second cysteine residue and the Cys-Cys sequence at a distance of 5-10 amino acid residues from the second cysteine; the Extra Structural Motif (ESM), which postulates the existence of a pair of CXC fragments in the C-region; and the Processing Quadruplet Motif (PQM), which specifies the Arg residue at position -1 and Glu residues at positions -2, -3, and/or -4 in the precursor sequences just before the postprocessing site. In the processed data bank we found 48 toxinlike structures with ion channel inhibitor motifs. These include agelenin earlier isolated from Agelena opulenta and 25 more homologous sequences, 15 homologs of mu-agatoxin 2 from the spider Agelenopsis aperta, 3 structures with low homology to omega-agatoxin-IIIA, and 4 new structures. Also we showed that toxinlike structures exceed two thirds of the overall database sequences.

    ID:194
  14. Korolkova Y.V., Bocharov E.V., Angelo K., Maslennikov I.V., Grinenko O.V., Lipkin A.V., Nosyreva E.D., Pluzhnikov K.A., Olesen S.P., Arseniev A.S., Grishin E.V. (2002). New binding site on common molecular scaffold provides HERG channel specificity of scorpion toxin BeKm-1. J. Biol. Chem. 277 (45), 43104–9 [+]

    The scorpion toxin BeKm-1 is unique among a variety of known short scorpion toxins affecting potassium channels in its selective action on ether-a-go-go-related gene (ERG)-type channels. BeKm-1 shares the common molecular scaffold with other short scorpion toxins. The toxin spatial structure resolved by NMR consists of a short alpha-helix and a triple-stranded antiparallel beta-sheet. By toxin mutagenesis study we identified the residues that are important for the binding of BeKm-1 to the human ERG K+ (HERG) channel. The most critical residues (Tyr-11, Lys-18, Arg-20, Lys-23) are located in the alpha-helix and following loop whereas the "traditional" functional site of other short scorpion toxins is formed by residues from the beta-sheet. Thus the unique location of the binding site of BeKm-1 provides its specificity toward the HERG channel.

    ID:195
  15. Korolkova Y.V., Kozlov S.A., Lipkin A.V., Pluzhnikov K.A., Hadley J.K., Filippov A.K., Brown D.A., Angelo K., Strøbaek D., Jespersen T., Olesen S.P., Jensen B.S., Grishin E.V. (2001). An ERG channel inhibitor from the scorpion Buthus eupeus. J. Biol. Chem. 276 (13), 9868–76 [+]

    The first selective blocker of K+ channels of ERG type BeKm was isolated from the venom of the scorpion Buthus eupeus. The peptide along with its mutants was produced in a heterological expression system and their properties were assessed on M-currents in the NG108-15 cell line, which allowed establishing the peptide’s pharmacophore. BeKm toxin became the first published selective inhibitor of hERG channels. At present it may be found on the market of bioactive substances.

    ID:85

Sergey Kozlov

  • Russia, Moscow, Ul. Miklukho-Maklaya 16/10 — On the map
  • IBCh RAS, build. 51, office. 363
  • Phone: +7(495)336 4022
  • E-mail: serg@ibch.ru

ω-Tbo-IT1 — selective inhibitor of insect channels isolated from Tibellus oblongus spider venom (2016-03-28)

Novel disulfide-containing polypeptide toxin was found in venom Tibellus oblongus spider from Central Asia region. Here, we report on isolation, spatial structure determination and electrophysiological characterization of this 41-residue toxin called ω-Tbo-IT1 It has insect toxic effect with LD50 14.3 μg/g in experiments on Musca domestica larvae. Electrophysiological experiments revealed a reversible inhibition of evoked excitatory postsynaptic currents in Calliphora vicina neuromuscular junction while parameters of spontaneous ones were not affected. Inhibition was concentration dependent with IC50 value 40±10 nM and Hill coefficient 3.4±0.3. The toxin did not affect frog neuro-muscular junction, glutamatergic and GABAergic transmission in rat brain. Ca2+ currents in Calliphora vicina muscle were not inhibited, whereas in cockroach neurons at least one type of voltage gated Ca2+ currents were inhibited by ω-Tbo-IT1. Thus, the toxin apparently acts as selective inhibitor of presynaptic insect Ca2+ channels. Spatial structure analysis of recombinant ω-Tbo-IT1 by NMR spectroscopy in aqueous solution revealed the set of 20 structures. The toxin comprises the conventional ICK (knottin) fold containing extended β-hairpin loop and γ-turn that are capable of doing — as we called it — “scissors-like mutual motions”. Alongside with alternative twisting of the β-sheet observed in the major β-hairpin loop such plasticity of the molecule (dynamic epitope) may play a crucial role for the receptor binding/recognition.

Publications

  1. Mikov A.N., Fedorova I.M., Potapieva N.N., Maleeva E.E., Andreev Y.A., Zaitsev A.V., Kim K.K., Bocharov E.V., Bozin T.N., Altukhov D.A., Lipkin A.V., Kozlov S.A., Tikhonov D.B., Grishin E.V. (2015). ω-Tbo-IT1-New Inhibitor of Insect Calcium Channels Isolated from Spider Venom. Sci Rep 5, 17232 [+]

    Novel disulfide-containing polypeptide toxin was discovered in the venom of the Tibellus oblongus spider. We report on isolation, spatial structure determination and electrophysiological characterization of this 41-residue toxin, called ω-Tbo-IT1. It has an insect-toxic effect with LD50 19 μg/g in experiments on house fly Musca domestica larvae and with LD50 20 μg/g on juvenile Gromphadorhina portentosa cockroaches. Electrophysiological experiments revealed a reversible inhibition of evoked excitatory postsynaptic currents in blow fly Calliphora vicina neuromuscular junctions, while parameters of spontaneous ones were not affected. The inhibition was concentration dependent, with IC50 value 40 ± 10 nM and Hill coefficient 3.4 ± 0.3. The toxin did not affect frog neuromuscular junctions or glutamatergic and GABAergic transmission in rat brains. Ca(2+) currents in Calliphora vicina muscle were not inhibited, whereas in Periplaneta americana cockroach neurons at least one type of voltage gated Ca(2+) current was inhibited by ω-Tbo-IT1. Thus, the toxin apparently acts as an inhibitor of presynaptic insect Ca(2+) channels. Spatial structure analysis of the recombinant ω-Tbo-IT1 by NMR spectroscopy in aqueous solution revealed that the toxin comprises the conventional ICK fold containing an extended β-hairpin loop and short β-hairpin loop which are capable of making "scissors-like mutual motions".

    ID:1341

A novel cysteine-rich antifungal peptide ToAMP4 from Taraxacum officinale Wigg. flowers (2016-03-28)

A novel peptide named ToAMP 4 was isolated from Taraxacum officinale Wigg. flowers by a combination of acetic acid extraction and different types of chromatography: affinity, size-exclusion, an d RP-H PLC. The amino acid sequence of ToAMP4 was determined by automated Edman degradation. The peptide is basic, consists of 41 amino acids , and incorporates three disulphide bonds. Due to the unusual cysteine spacing pattern, ToAMP4 doe s not belong to any known plant AMP family, but classifies together with two other antimicrobial peptides ToAMP1 and ToAMP2 previously isolated from the dandelion flowers. To study the biological activity of ToAMP4 , it was success fully produced in a prokaryotic expression system as a fusion protein with thioredoxin. The recombinant peptide was shown to be identical to the native ToAMP4 by chromatographic behavior, molecular mass, and N-terminal amino acid sequence. The peptide displays broad-spectrum antifungal activity against important phytopathogens. Two ToAMP4 -mediated inhibition strategies depending on the fungus were demonstrated. The results obtained add to our knowledge on the structural and function al diversity of AMPs in plants.

Publications

  1. Astafieva A.A., Enyenihi A.A., Rogozhin E.A., Kozlov S.A., Grishin E.V., Odintsova T.I., Zubarev R.A., Egorov T.A. (2015). Novel proline-hydroxyproline glycopeptides from the dandelion (Taraxacum officinale Wigg.) flowers: de novo sequencing and biological activity. Plant Sci. 238, 323–9 [+]

    Two novel homologous peptides named ToHyp1 and ToHyp2 that show no similarity to any known proteins were isolated from Taraxacum officinale Wigg. flowers by multidimensional liquid chromatography. Amino acid and mass spectrometry analyses demonstrated that the peptides have unusual structure: they are cysteine-free, proline-hydroxyproline-rich and post-translationally glycosylated by pentoses, with 5 carbohydrates in ToHyp2 and 10 in ToHyp1. The ToHyp2 peptide with a monoisotopic molecular mass of 4350.3Da was completely sequenced by a combination of Edman degradation and de novo sequencing via top down multistage collision induced dissociation (CID) and higher energy dissociation (HCD) tandem mass spectrometry (MS(n)). ToHyp2 consists of 35 amino acids, contains eighteen proline residues, of which 8 prolines are hydroxylated. The peptide displays antifungal activity and inhibits growth of Gram-positive and Gram-negative bacteria. We further showed that carbohydrate moieties have no significant impact on the peptide structure, but are important for antifungal activity although not absolutely necessary. The deglycosylated ToHyp2 peptide was less active against the susceptible fungus Bipolaris sorokiniana than the native peptide. Unique structural features of the ToHyp2 peptide place it into a new family of plant defense peptides. The discovery of ToHyp peptides in T. officinale flowers expands the repertoire of molecules of plant origin with practical applications.

    ID:1474