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Diffusion of One-Dimensional Crystals in Channels of Single-Walled Carbon Nanotubes. CRYSTALLOGR REP+ 2018. [DOI: 10.1134/s1063774518030355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
The paper reports the relationship between single-walled carbon nanotube (SWNT) doping and capsulate crystal structure in RbxAg1−xI@SWNT composites.
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Electron microscopy study of new composite materials based on electrospun carbon nanofibers. CrystEngComm 2017. [DOI: 10.1039/c7ce00599g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To create a new type of catalytic gas diffusion layer for a high-temperature hydrogen/air polymer-electrolyte membrane fuel cell (HT-PEMFC), a new electrospun carbon nanofiber (CNF)-based platinized nanocomposite was formed.
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4
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The structure and continuous stoichiometry change of 1DTbBrx@SWCNTs. J Microsc 2015; 262:92-101. [PMID: 26625140 DOI: 10.1111/jmi.12348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/29/2015] [Indexed: 11/29/2022]
Abstract
HRTEM and HAADF STEM of 1DTbBrx@SWCNT meta-nanotubes reveal three structural modifications of 1D nanocrystals within single wall carbon nanotube channels attributed to a different stoichiometry of the guest crystal. For SWCNTs with diameters Dm > 1.4 nm a most complete tetragonal unit cell is observed. When crystallization occurs inside SWCNT with Dm < 1.4 nm 1D TbBrx crystal deforms a nanotube to elliptical shape in cross section. In this case the 1D crystal unit cell becomes monoclinic, with possible loss of a part of bromine atoms. Two modifications of a monoclinic unit cell appear. One of them is characterized by single or pair vacancies in the structure of the 1D crystal. Another structure is explained by peripheral and central bromine atoms loss. An appearance of such modifications can be stimulated by electron irradiation. The loss of bromine atoms is in agreement with chemical analysis data. Electronic properties of obtained meta-nanotubes are investigated using optical absorption and Raman spectroscopy. It is shown that intercalation of terbium bromide into SWCNTs leads to acceptor doping of SWCNTs. According to local EDX analysis and elemental mapping this doping can arise from significant stoichiometry change in 1D nanocrystal indicating an average Tb:Br atomic ratio of 1:2.8 ± 0.1.
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Characterization of SWCNT products manufactured in Russia and the prospects for their industrial application. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s1995078015040096] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Genome packaging in EL and Lin68, two giant phiKZ-like bacteriophages of P. aeruginosa. Virology 2014; 468-470:472-478. [PMID: 25254945 DOI: 10.1016/j.virol.2014.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 06/01/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
Abstract
A unique feature of the Pseudomonas aeruginosa giant phage phiKZ is its way of genome packaging onto a spool-like protein structure, the inner body. Until recently, no similar structures have been detected in other phages. We have studied DNA packaging in P. aeruginosa phages EL and Lin68 using cryo-electron microscopy and revealed the presence of inner bodies. The shape and positioning of the inner body and the density of the DNA packaging in EL are different from those found in phiKZ and Lin68. This internal organization explains how the shorter EL genome is packed into a large EL capsid, which has the same external dimensions as the capsids of phiKZ and Lin68. The similarity in the structural organization in EL and other phiKZ-like phages indicates that EL is phylogenetically related to other phiKZ-like phages, and, despite the lack of detectable DNA homology, EL, phiKZ, and Lin68 descend from a common ancestor.
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The structure and electronic properties of copper iodide 1D nanocrystals within single walled carbon nanotubes. ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/471/1/012035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Design of electrodes based on a carbon nanofiber nonwoven material for the membrane electrode assembly of a polybenzimidazole-membrane fuel cell. DOKLADY PHYSICAL CHEMISTRY 2013. [DOI: 10.1134/s0012501613020036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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One-dimensional SnF2 single crystals in the inner channels of single-wall carbon nanotubes: II. Structure and nanocomposite construction modeling. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s1063774510040267] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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One-dimensional SnF2 single crystals in the inner channels of single-wall carbon nanotubes: I. Preparation and basic characterization. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s1063774510030223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Investigation of the formation of nanowires from silicon whiskers. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s1063774510030211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Preparation and properties of single-walled nanotubes filled with inorganic compounds. RUSSIAN CHEMICAL REVIEWS 2009. [DOI: 10.1070/rc2009v078n09abeh004077] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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The Behaviour of 1D CuI Crystal@SWNT Nanocomposite under Electron Irradiation. ACTA ACUST UNITED AC 2008. [DOI: 10.1063/1.2918119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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17
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Gamma-radiolysis of aqueous suspensions of single-wall carbon nanotubes. DOKLADY PHYSICAL CHEMISTRY 2006. [DOI: 10.1134/s0012501606070025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
Diamond single crystals were grown on the silicon whiskers by a hot filament chemical vapor deposition technique at the filament temperature about 2100 degrees C and the temperature of support 800 degrees C. Specimens were examined by SEM, TEM, HRTEM and SAED. When the filament temperature was about 1900 degrees C globular polycrystalline diamond particles were grown. At a support temperature more then 800 degrees C SiC nanoparticles were formed. To investigate the ion etching process of the silicon tip/diamond system, tips were treated with an Ar(+) beam with energy up to 30 kV. The results depend on fluence: at 4 x 10(18)ion/cm(2) diamonds and partially Si tips were destroyed, amorphous layer was formed (sometimes with nanometric size fragments of diamond); at 1 x 10(18)ion/cm(2) sharpened diamonds (radius of curvature about 20 nm) covered with amorphous layer (radius about 80 nm) probably with nanoclusters of diamond were observed; at 4.4 x 10(17) ion/cm(2) there was no visible tip sharpening but formation of amorphous thick layer occurred. The emission characteristics of Si tips covered with diamond were improved due to ion treatment. Since such tips in our case were covered with amorphous layer containing nanometric size fragments of diamond, we suppose this layer is responsible for electron emission improvement.
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20
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[Max Perutz]. Mol Biol (Mosk) 2002; 36:553-7. [PMID: 12068643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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23
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High-resolution electron microscopy of ZnO grain boundaries in bicrystals obtained by the solid-phase intergrowth process. ACTA ACUST UNITED AC 1997. [DOI: 10.1080/01418619708214026] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Abstract
Infectious bursal disease virus (IBDV), a member of the Birnaviridae group, is a commercially important pathogen of chickens. From electron micrographs of frozen, hydrated, unstained specimens, we have computed a three-dimensional map of IBDV at about 2 nm resolution. The map shows that the structure of the virus is based on a T=13 lattice and that the subunits are predominantly trimer clustered. The subunits close to the fivefold symmetry axes are at a larger radius than those close to the two- or threefold axes, giving the capsid a markedly nonspherical shape. The trimer units on the outer surface protrude from a continuous shell of density. On the inner surface, the trimers appear as Y-shaped units, but the set of units surrounding the fivefold axes appears to be missing. It is likely that the outer trimers correspond to the protein VP2, carrying the dominant neutralizing epitope, and the inner trimers correspond to protein VP3, which has a basic carboxy-terminal tail expected to interact with the packaged RNA.
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Abstract
Human hepatitis B virus core protein expressed in E. coli assembles into two sizes of particle. We have determined their three-dimensional structures by electron cryomicroscopy and image processing. The large and small particles correspond to triangulation number T = 4 and T = 3 dimer clustered packings, containing 240 and 180 protein subunits, respectively. The local packing of subunits is very similar in the two sizes of particle and shows holes or channels through the shell. The native viral core particle packages RNA and is active in reverse transcription to DNA. The holes we observe may provide access for the necessary small molecules. Shells assembled from the intact core protein contain additional material, probably RNA, which appears as an icosahedrally ordered inner shell in the three-dimensional map.
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Abstract
Negative staining, some closely related alternative preparation techniques and radiation stability are considered. An attempt is made to clarify the mechanism of action and ultimate resolution limit of negative staining. The results of electron diffraction investigation of thermitase microcrystals embedded in glucose and glucose + stains are presented. It is shown that at doses not exceeding 10 electrons/nm2 electron diffraction from thermitase crystals demonstrate diffraction fields up to 0.2 nm. When adding heavy-atom salts to glucose or using negative staining, the relative intensities of reflections change and electron diffraction patterns for every type of heavy-atom additive (or negative stain) have their specific features. Such characteristic changes of reflection intensities indicate specific interaction of these additives (or stains) with the object. In the case of electron diffraction from the crystals stained using the routine negative staining technique the ordering was preserved down to 0.4-0.5 nm. Increasing the dose up to the normal value results in fading of distant reflections. Thus, negative staining with radiation doses less than the critical one could yield resolution down to 0.4 nm. Yet, the structure may change due to interaction with the stain. Nevertheless, the possibility that such resolution could be obtained for a limited number of objects should not be excluded. Some examples of the application of negative staining for investigation of quaternary and domain structure of proteins (nitrogenase, glutamine synthetase, mitochondrial ATP-synthase, membrane monooxygenase enzymes), tubular and two-dimensional protein crystals (catalase, phosphorylase, HWV protein, hydrogenase), as well as ribosomes and bacteriophages are given in the review.
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Abstract
Elongated hollow strands were revealed on raw images and averaged by the correlation method images of the 30 S subunit of the E. coli ribosome negatively stained by uranyl acetate. The tentative three-dimensional arrangement of the 'strands' and their nature are discussed.
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Electron microscopy of the Mo-Fe-protein from Azotobacter vinelandii nitrogenase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 149:389-92. [PMID: 3858099 DOI: 10.1111/j.1432-1033.1985.tb08937.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The quaternary structure of the Mo-Fe-protein from Azotobacter vinelandii has been studied by electron microscopy. A model of the molecule of the Mo-Fe-protein has been proposed: two alpha subunits are displaced relative to two beta subunits along a twofold axis, so the molecule can be characterized by the point-group pseudosymmetry 222. Computer averaging of the images showed that one of the projections of the molecule could be characterized by twofold rotational symmetry. Micrographs of nitrogenase recombined complex (Mo-Fe-protein + Fe-protein) have been obtained. They showed particles close in size and form to the Mo-Fe-protein molecule. Therefore, it has been proposed that the Fe-protein could be situated in the central cavity of Mo-Fe-protein.
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Strand-like structures and their three-dimensional organization in the large subunit of the Escherichia coli ribosome. Mol Biol Rep 1982; 8:191-7. [PMID: 6761579 DOI: 10.1007/bf00776579] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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30
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31
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Abstract
It has been shown that in some cases negative staining reveals structure with details down to 0.4 nm in size, the nature of protein playing a key role. Various stains seem to interact with different parts of a thermitase (a serine protease) molecule, which results in intensity changes in electron diffraction patterns.
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Electron microscope study on human ceruloplasmin. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1979; 14:161-8. [PMID: 489254 DOI: 10.1111/j.1399-3011.1979.tb01739.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electron microscopy of human ceruloplasmin (CP) molecules revealed a few distinctive types of particle images. Analysis of these images allows to propose a tentative model for CP: six "subunits" (which we call domains) not much different in size are arranged with 32 point group pseudosymmetry. The determination of the number of polypeptides arising at the spontaneous specific proteolytic fragmentation of CP and their molecular weights conform with this assumption. The electrophoretic studies of the CP samples prepared both with and without potent proteolytic inhibitor, PMSF, revealed that CP is a single-chain protein with molecular weight of 130 000. Isolated and stored without PMSF the polypeptide chain of CP undergoes specific proteolytic cleavage which results in the appearance of polypeptides with molecular weights of 16 000, 48 000, and 64 000. The latter two polypeptides degradate to about two- and three-fold decreased molecular weights fragments, respectively. Therefore, the single polypeptide chain of CP contains at least five peptide bonds which are particularly susceptible to proteolytic attack and which connect six principal segments of the chain. The hydrolysis of these bonds results in liberation of the six fragments which were integrated in the enzymatically active globule of CP.
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35
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[Purification, properties and quaternary structure of glutamine synthetase from Chlorella]. BIOKHIMIIA (MOSCOW, RUSSIA) 1977; 42:350-8. [PMID: 15657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A highly purified preparation of glutamine synthetase from chlorella grown on a medium containing nitrate as a sole source of nitrogen, was isolated and characterized by disc-electrophoresis and analytical ultracentrifugation. The N-terminal amino acid of glutamine synthetase is glycine. The molecular weight of glutamine synthetase is 32.000; its activity in the presence of Mg2+ was 150 mkmol o-phosphate per min per mg protein. The molecular weight of subunits of the enzyme, equal to 53.000 was determined by disc-electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. Electron microscopy of negatively contrasted enzyme preparations revealed 6 subunits in the enzyme molecule, arranged in a point symmetry group 32.
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36
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[The structure of microtubules]. Mol Biol (Mosk) 1976; 10:445-51. [PMID: 940561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cytoplasmic microtubules, plane monolayers of tubulin filaments and single filaments have been investigated by electron microscopy. The methods of optical diffraction, filtering and three-dimensional reconstruction have been used to analyse the micrographs and to construct a model of the dimeric molecule of tubulin. When viewed in the direction perpendicular to the longitudinal axes the molecule bear resemblance to the figure "8". When rotated by 90 degrees it looks as if composed of two globules. Two variants of the quoternary structure are considered: 1) each of two subunits is a deformed ring; 2) each rings of the "8"-like particles consists of two halves of different subunits. The second protein layer which is formed on microtubules in the presence of protamine consists of tubulin and is characterized by the crystal lattice similar to that of the microtubule itself, but rotated through the angle of about 95 degrees. In the presence of protamine we also detected flat spirals and stacks of such spirals forming short tubules.
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The structure of liver ribosomes. Mol Biol 1974; 7:496-507. [PMID: 4132953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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41
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Electron microscopy of muscle phosphorylase B. Mol Biol 1972; 5:510-23. [PMID: 4133093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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[Crystallization (polymerization) of the complex of tryptophanyl-tRNA-synthetase with tryptophan]. DOKLADY AKADEMII NAUK SSSR 1971; 199:1178-80. [PMID: 5126561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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A double-helical structure found on the re-aggregation of the protein of barley stripe mosaic virus. J Mol Biol 1969; 39:673-4. [PMID: 5357218 DOI: 10.1016/0022-2836(69)90153-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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50
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