Масленников Иннокентий Вячеславович

Кандидат физико-математических наук


Эл. почта: maslennikov@salk.edu

Избранные публикации

  1. Goncharuk M.V., Shulga A.A., Ermoliuk Ia.S., Tkach E.N., Goncharuk S.A., Pustovalova Iu.E., Mineev K.S., Bocharov E.V., Maslennikov I.V., Arsenev A.S., Kirpichnikov M.P. (2011). [Bacterial synthesis, purification, and solubilization of transmembrane segments of ErbB family members]. Mol. Biol. (Mosk.) 45 (5), 892–902 [+]

    A family of epidermal growth factor receptors, ErbB, represents an important class of receptor tyrosine kinases, playing a leading role in cellular growth, development and differentiation. Transmembrane domains of these receptors transduce biochemical signals across plasma membrane via lateral homo- and heterodimerization. Relatively small size of complexes of ErbB transmembrane domains with detergents or lipids allows one to study their detailed spatial structure using three-dimensional heteronuclear high-resolution NMR spectroscopy. Here, we describe the effective expression system and purification procedure for preparative-scale production of transmembrane peptides from four representatives of ErbB family, ErbB1, ErbB2, ErbB3, ErbB4, for structural studies. The recombinant peptides were produced in Escherichia coli BL21(DE3)pLysS as C-terminal extensions of thioredoxin A. The fusion protein cleavage was accomplished with the light subunit of human enterokinase. Several (10-30) milligrams of purified isotope-labeled transmembrane peptides were isolated with the use of a simple and convenient procedure, which consists of consecutive steps of immobilized metal affinity chromatography and cation-exchange chromatography. The purified peptides were reconstituted in lipid/detergent environment (micelles or bicelles) and characterized using dynamic light scattering, CD and NMR spectroscopy. The data obtained indicate that the purified ErbB transmembrane peptides are suitable for structural and dynamic studies of their homo- and heterodimer complexes using high resolution NMR spectroscopy.

    ID:695
  2. Mineev K.S., Bocharov E.V., Volynsky P.E., Goncharuk M.V., Tkach E.N., Ermolyuk Y.S., Schulga A.A., Chupin V.V., Maslennikov I.V., Efremov R.G., Arseniev A.S. (2011). Dimeric structure of the transmembrane domain of glycophorin a in lipidic and detergent environments. Acta Naturae 3 (2), 90–8 [+]Specific interactions between transmembrane α-helices, to a large extent, determine the biological function of integral membrane proteins upon normal development and in pathological states of an organism. Various membrane-like media, partially those mimicking the conditions of multicomponent biological membranes, are used to study the structural and thermodynamic features that define the character of oligomerization of transmembrane helical segments. The choice of the composition of the membrane-mimicking medium is conducted in an effort to obtain a biologically relevant conformation of the protein complex and a sample that would be stable enough to allow to perform a series of long-term experiments with its use. In the present work, heteronuclear NMR spectroscopy and molecular dynamics simulations were used to demonstrate that the two most widely used media (detergent DPC micelles and lipid DMPC/DHPC bicelles) enable to perform structural studies of the specific interactions between transmembrane α-helices by the example of dimerizing the transmembrane domain of the bitopic protein glycophorin A. However, a number of peculiarities place lipid bicelles closer to natural lipid bilayers in terms of their physical properties. ID:712
  3. Bocharov E.V., Pustovalova Y.E., Pavlov K.V., Volynsky P.E., Goncharuk M.V., Ermolyuk Y.S., Karpunin D.V., Schulga A.A., Kirpichnikov M.P., Efremov R.G., Maslennikov I.V., Arseniev A.S. (2007). Unique dimeric structure of BNip3 transmembrane domain suggests membrane permeabilization as a cell death trigger. J. Biol. Chem. 282 (22), 16256–66 [+]

    BNip3 is a prominent representative of apoptotic Bcl-2 proteins with rather unique properties initiating an atypical programmed cell death pathway resembling both necrosis and apoptosis. Many Bcl-2 family proteins modulate the permeability state of the outer mitochondrial membrane by forming homo- and hetero-oligomers. The structure and dynamics of the homodimeric transmembrane domain of BNip3 were investigated with the aid of solution NMR in lipid bicelles and molecular dynamics energy relaxation in an explicit lipid bilayer. The right-handed parallel helix-helix structure of the domain with a hydrogen bond-rich His-Ser node in the middle of the membrane, accessibility of the node for water, and continuous hydrophilic track across the membrane suggest that the domain can provide an ion-conducting pathway through the membrane. Incorporation of the BNip3 transmembrane domain into an artificial lipid bilayer resulted in pH-dependent conductivity increase. A possible biological implication of the findings in relation to triggering necrosis-like cell death by BNip3 is discussed.

    ID:713
  4. Kasheverov I.E., Chiara D.C., Zhmak M.N., Maslennikov I.V., Pashkov V.S., Arseniev A.S., Utkin Y.N., Cohen J.B., Tsetlin V.I. (2006). alpha-Conotoxin GI benzoylphenylalanine derivatives. (1)H-NMR structures and photoaffinity labeling of the Torpedo californica nicotinic acetylcholine receptor. FEBS J. 273 (7), 1373–88 [+]

     

    С использованием фотоактивируемого производного одного из конотоксинов методом фотоаффинной модификации проведено частичное картирование лиганд-связывающего участка природного холинорецептора. Исходя из полученных данных, компьютерным моделированием предположена возможность двух ориентаций молекулы пептида в этом участке.

     

    ID:189
  5. Jiang M., Zhang M., Maslennikov I.V., Liu J., Wu D.M., Korolkova Y.V., Arseniev A.S., Grishin E.V., Tseng G.N. (2005). Dynamic conformational changes of extracellular S5-P linkers in the hERG channel. J. Physiol. (Lond.) 569 (Pt 1), 75–89 [+]The hERG channel has an unusually long 'S5-P linker' (residues 571-613) that lines the outer mouth of the pore. Previously, we have shown that residues along this S5-P linker are critical for the fast-inactivation process and K(+) selectivity of the hERG channel. Here we used several approaches to probe the structure of this S5-P linker and its interactions with other domains of the hERG channel. Circular dichroism and NMR analysis of a synthetic hERG S5-P linker peptide suggested that this linker is quite dynamic: its central region (positions 583-593) can be unstructured or helical, depending on whether it is immersed in an aqueous phase or in contact with a hydrophobic environment. Cysteine introduced into positions 583-597 of the S5-P linker can form intersubunit disulphide bonds, and at least four of them (at 584, 585, 588 and 589) can form disulphide bonds with counterparts from neighbouring subunits. We propose that the four S5-P linkers in a hERG channel can engage in dynamic conformational changes during channel gating, and interactions between S5-P linkers from neighbouring subunits contribute importantly to channel inactivation. ID:714
  6. Kasheverov I.E., Zhmak M.N., Maslennikov I.V., Utkin Y.N., Tsetlin V.I. (2003). A comparative study on selectivity of alpha-conotoxins GI and ImI using their synthetic analogues and derivatives. Neurochem. Res. 28 (3-4), 599–606 [+]

    Comparative structure-function studies have been carried out for alpha-conotoxin GI acting on nicotinic acetylcholine receptors (AChR) from mammalian muscles and from the electric organ of the Torpedo californica ray and for alpha-conotoxin ImI, which targets the neuronal alpha7 AChR. A series of analogs has been prepared for this purpose: chemically modified derivatives, including a covalently linked dimer of GI, as well as analogs wherein one or several amino acid residues have been changed using solid-phase peptide synthesis. The activity of all compounds was assessed in competition with radioiodinated and/or tritiated alpha-conotoxin GI for binding to the membrane-bound AChR of Torpedo californica. Binding of radioiodinated alpha-conotoxin GI dimer was also monitored directly, revealing the largest, as compared to all other analogues, difference in the affinity between the two binding sites in the receptor (KD approximately 11 and 1200 nM). Comparison of binding data with the results of CD measurements point to important role of the spatial organization of the alpha-conotoxin second loop in manifestation of their "muscle" or "neuronal" specificity.

    ID:715
  7. 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