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We developed a method for the fast transformation of virions of tobacco mosaic virus (TMV) in so-called spherical particles (SPs) of different sizes. These SPs turned out to be highly useful for the preparation of different kinds of important biotechnological products. In this communication, we report that a representative of the flexuous helical virus group-potato virus X (PVX), produces SPs as well, but these SPs differ from TMV SPs in several important aspects. PVX SPs may be useful biotechnological devices. [ABSTRACT FROM AUTHOR]

Two new tetranuclear copper(II) complexes [Cu4(μ4-O)( L1)Cl4] ( 1) and [Cu4(μ4-O)( L2)2Cl4] ( 2), where H2L1 is a macrocyclic ligand resulting from [2+2] condensation of 2,6-diformyl-4-methylphenol (DFF) and 1,3-bis(aminopropyl)tetramethyldisiloxane, and HL2 is a 1:2 condensation product of DFF with trimethylsilyl p-aminobenzoate, have been prepared. The structures of the products were established by X-ray diffraction. The complexes have been characterised by FTIR, UV/Vis spectroscopy, ESI mass-spectrometry and magnetic susceptibility measurements. The latter revealed that the tetranuclear complexes can be described as two ferromagnetically coupled dinuclear units, in which the two copper(II) ions interact antiferromagnetically. The compounds act as homogeneous catalyst precursors for a number of single-pot reactions, including (i) hydrocarboxylation, with CO, H2O and K2S2O8, of a variety of linear and cyclic( n = 5-8) alkanes into the corresponding C n+1 carboxylic acids, (ii) peroxidative oxidation of cyclohexane, and (iii) solvent-free microwave-assisted oxidation of 1-phenylethanol. [ABSTRACT FROM AUTHOR]

The reaction of 2,6-diformyl-4-methylphenol with 1,3-bis(3-aminopropyl)tetramethyldisiloxane in the presence of MnCl2 in a 1:1:2 molar ratio in methanol afforded a dinuclear μ-chlorido-bridged manganese(II) complex of the macrocyclic [2+2] condensation product (H2L), namely, [Mn2Cl2(H2L)(HL)]Cl ·3H2O ( 1). The latter afforded a new compound, namely, [Mn2Cl2(H2L)2][MnCl4] ·4CH3CN ·0.5CHCl3 ·0.4H2O ( 2), after recrystallisation from 1:1 CHCl3/CH3CN. The co-existence of the free and complexed azomethine groups, phenolato donors, μ-chlorido bridges, and the disiloxane unit were well evidenced by ESI mass spectrometry and FTIR spectroscopy and confirmed by X-ray crystallography. The magnetic measurements revealed an antiferromagnetic interaction between the two high-spin ( S = 5/2, g = 2) manganese(II) ions through the μ-chlorido bridging ligands. The electrochemical behaviour of 1 and 2 has been studied, and details of their redox properties are reported. Both compounds act as catalysts or catalyst precursors in the solvent-free low-power microwave-assisted oxidation of selected secondary alcohols, for example, 1-phenylethanol, cyclohexanol, 2- and 3-octanol, to the corresponding ketones in the absence of solvent. The highest yield of 72 % was achieved for 1-phenylethanol by using a maximum of 1 % molar ratio of catalyst relative to substrate. [ABSTRACT FROM AUTHOR]

Mononuclear copper(II) salen-type Schiff base complexes, CuIIL1-5 [H2L1 to H2L5 = tetradentate N, N, O, O ligands derived from 2-hydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 3,5-dibromo-2-hydroxybenzaldehyde, 2-hydroxy-5-nitrobenzaldehyde, 5-chloro-2-hydroxybenzaldehyde and 1,3-bis(3-aminopropyl)tetramethyldisiloxane, respectively] were prepared in situ in the presence of a copper(II) salt or by direct complexation between a copper(II) salt and a presynthesised Schiff base. The compounds {CuL1, CuL1 ·0.5Py, CuL2 ·0.375CH2Cl2, (CuL3)[Cu(4-Me-Py)4Cl]Cl ·2H2O, CuL4, CuL4 ·CHCl3 and CuL5, as well as the isolated ligand H2L3} were characterised by elemental analysis, spectroscopic methods (IR, UV/Vis, 1H NMR, EPR) and X-ray crystallography. The formation of a 12-membered central chelate ring in these complexes is effected by the tetramethyldisiloxane unit, which separates the aliphatic chains, thus significantly reducing the mechanical strain in such a chelate ring. We dub this a 'shoulder yoke effect' by analogy with the load-spreading ability of such an ancient device. The coordination geometry of copper(II) in CuIIL1-5 can be described as tetrahedrally distorted square-planar. Maximum tetrahedral distortion of the coordination geometry expressed by the parameter τ4 was observed for CuL1 (0.460), while distortion was minimal for the two crystallographically independent molecules of CuL2 (0.219 and 0.284). The Si-O-Si bond angle varies markedly between 169.75(2)° for CuL1 and 154.2(3)° for CuL4 ·CHCl3. Charge-density and DFT calculations on CuL1 indicate high ionic character of the Si-O bonds in the tetramethyldisiloxane fragment. The new copper(II) complexes bearing the disiloxane moiety have been shown to act as catalyst precursors for the aerobic oxidation of benzyl alcohol to benzaldehyde mediated by the TEMPO radical, reaching yields and TONs up to 99 % and 990, respectively, under mild and environmentally friendly conditions (50 °C; MeCN/H2O, 1:1). [ABSTRACT FROM AUTHOR]

SUMMARY Previously, we have reported that intact Potato virus X (PVX) virions cannot be translated in cell-free systems, but acquire this capacity by the binding of PVX-specific triple gene block protein 1 (TGBp1) or after phosphorylation of the exposed N-terminal segment of intravirus coat protein (CP) by protein kinases. With the help of in vitro mutagenesis, a nonphosphorylatable PVX mutant (denoted ST PVX) was prepared in which all 12 S and T residues in the 20-residue-long N-terminal CP segment were substituted by A or G. Contrary to expectations, ST PVX was infectious, produced normal progeny and was translated in vitro in the absence of any additional factors. We suggest that the N-terminal PVX CP segment somehow participates in virion assembly in vivo and that CP subunits in ST virions may differ in structure from those in the wild-type (UK3 strain). In the present work, to test this suggestion, we performed a comparative tritium planigraphy study of CP structure in UK3 and ST virions. It was found that the profile of tritium incorporation into ST mutant virions in some CP segments differed from that of normal UK3 virions and from UK3 complexed with the PVX movement protein TGBp1. It is proposed that amino acid substitutions in ST CP and the TGBp1-driven remodelling of UK3 virions induce structural alterations in intravirus CPs. These alterations affect the predicted RNA recognition motif of PVX CP, but in different ways: for ST PVX, labelling is increased in α-helices 6 and 7, whereas, in remodelled UK3, labelling is increased in the β-sheet strands β3, β4 and β5. [ABSTRACT FROM AUTHOR]

The structure of the C-terminal domain of the influenza virus A matrix M1 protein, for which X-ray diffraction data were still missing, was studied in acidic solution. Matrix M1 protein was bombarded with thermally-activated tritium atoms, and the resulting intramolecular distribution of the tritium label was analyzed to assess the steric accessibility of the amino acid residues in this protein. This technique revealed that interdomain loops and the C-terminal domain of the protein are the most accessible to labeling with tritium atoms. A model of the spatial arrangement of the C-terminal domain of matrix M1 protein was generated using rosetta software adjusted to the data obtained by tritium planigraphy experiments. This model suggests that the C-terminal domain is an almost flat layer with a three-α-helical structure. To explain the high level of tritium label incorporation into the C-terminal domain of the M1 protein in an acidic solution, we also used independent experimental approaches (CD spectroscopy, limited proteolysis and MALDI-TOF MS analysis of the proteolysis products, dynamic light scattering and analytical ultracentrifugation), as well as multiple computational algorithms, to analyse the intrinsic protein disorder. Taken together, the results obtained in the present study indicate that the C-terminal domain is weakly structured. We hypothesize that the specific 3D structural peculiarities of the M1 protein revealed in acidic pH solution allow the protein greater structural flexibility and enable it to interact effectively with the components of the host cell. [ABSTRACT FROM AUTHOR]

Alterations in Potato virus X (PVX) coat protein structure after binding of the protein, encoded by the first gene of PVX triple gene block (triple gene block 1 protein, TGBp1), to the virions were studied using tritium planigraphy. Previously, it has been shown that TGBp1 molecules interact with the PVX particle end, containing the 5′-terminus of PVX RNA, and that this interaction results in a strong decrease in virion stability and its transformation to a translationally active state. In this work, it has been shown that the interaction of TGBp1 with PVX virions leads to an increase of ∼ 50% in tritium label incorporation into the 176–198 segment of the 236-residue-long PVX coat protein subunit, with some decrease in label incorporation into the N-terminal coat protein region. According to the new ‘sandwich’ variant of our recently proposed model of the three-dimensional structure of the intravirus PVX coat protein, the 176–198 segment is assigned to the β-sheet region located at the subunit surface, presumably participating in coat protein interactions with the intravirus RNA and/or in protein–protein interactions, whereas the N-terminal coat protein region corresponds to the other part of the same β-sheet. For the remaining segments of the PVX coat protein subunit, no significant difference between tritium incorporation into untreated and TGBp1-treated PVX was observed. A detailed description of the ‘sandwich’ version of the intravirus PVX coat protein model is presented. [ABSTRACT FROM AUTHOR]

This paper summarizes some structural characteristics of Potato virus X (PVX), the flexuous filamentous plant potexvirus. A model of PVX coat protein (CP) tertiary structure in the virion proposed on the basis of tritium planigraphy combined with predictions of the protein tertiary structure is described. A possible role of glycosylation and phosphorylation in the CP structure and function is discussed. Two forms of PVX virion disassembly are discussed: (i) the virion co-translational disassembly after PVX CP in situ phosphorylation and (ii) disassembly of PVX triggered by different factors after linear destabilization of the virion by binding of the PVX-coded movement protein (TGBp1) to one end of the polar CP-helix. Special emphasis was placed on a translational activation of encapsidated PVX RNA and rapid disassembly of TGBp1-PVX complexes into free RNA and CP. The results of experiments on the PVX CP repolymerization and PVX reconstitution are considered. In particular, the products assembled from PVX RNA, CP and TGBp1 were examined. Single-tailed particles were found with a helical, head-like structure consisting of helically arranged CP subunits located at the 5′-tail of RNA; the TGBp1 was bound to the end of the head. Translatable ‘RNA-CP-TGBp1’ complexes may represent the transport form of the PVX infection. [ABSTRACT FROM AUTHOR]

The primary structures of N-terminal 19-mer peptides, released by limited trypsin treatment of coat protein (CP) subunits in intact virions of three potato virus X (PVX) isolates, were analyzed. Two wild-type PVX strains, Russian (Ru) and British (UK3), were used and also the ST mutant of UK3 in which all 12 serine and threonine residues in the CP N-terminal segment were replaced by glycine or alanine. With the help of direct carbohydrate analysis and MS, it was found that the acetylated N-terminal peptides of both wild-type strains are glycosylated by a single monosaccharide residue (galactose or fucose) at NAcSer in the first position of the CP sequence, whereas the acetylated N-terminal segment of the ST mutant CP is unglycosylated. Fourier transform infrared spectra in the 1000–4000 cm−1 region were measured for films of the intact and in situ trypsin-degraded PVX preparations at low and high humidity. These spectra revealed the presence of a broad-band in the region of valent vibrations of OH bonds (3100–3700 cm−1), which can be represented by superposition of three bands corresponding to tightly bound, weakly bound, and free OH groups. On calculating difference (‘wet’ minus ‘dry’) spectra, it was found that the intact wild-type PVX virions are characterized by high water-absorbing capacity and the ability to order a large number of water molecules on the virus particle. This effect was much weaker for the ST mutant and completely absent in the trypsin-treated PVX. It is proposed that the surface-located and glycosylated N-terminal CP segments of intact PVX virions induce the formation of a columnar-type shell from bound water molecules around the virions, which probably play a major role in maintaining the virion surface structure. [ABSTRACT FROM AUTHOR]

Spatial organization of wild-type (strain U1) tobacco mosaic virus (TMV) and of the temperature-sensitive TMV ts21–66 mutant was compared by tritium planigraphy. The ts21–66 mutant contains two substitutions in the coat protein (Ile21→Thr and Asp66→Gly) and, in contrast with U1, induces a hypersensitive response (formation of necroses) on the leaves of plants bearing a host resistance gene N ′ (for example Nicotiana sylvestris ); TMV U1 induces systemic infection (mosaic) on the leaves of such plants. Tritium distribution along the coat protein (CP) polypeptide chain was determined after labelling of both isolated CP preparations and intact virions. In the case of the isolated low-order (3–4S) CP aggregates no reliable differences in tritium distribution between U1 and ts21–66 were found. But in labelling of the intact virions a significant difference between the wild-type and mutant CPs was observed: the N-terminal region of ts21–66 CP incorporated half the amount of tritium than the corresponding region of U1 CP. This means that in U1 virions the CP N-terminal segment is more exposed on the virion surface than in ts21–66 virions. The possibility of direct participation of the N-terminal tail of U1 CP subunits in the process of the N ′ hypersensitive response suppression is discussed. [ABSTRACT FROM AUTHOR]

The article presents information on the strategy for national science policy in the USSR. The modem scientific and technical revolution essentially entails the progressive transformation of a growing number of branches of science into a direct productive and social force. The unified state policy for science and technology was established to enable the powerful forces of modern science to make the greatest possible contribution to the interests of society in the USSR and is being put into effect and improved with that end in view. The country has built up a rich fund of experience over many years in the development and implementation of this policy. The strategic policy for the activity of organizations in the area of science and scientific services in the USSR is governed by the basic criteria for long-term action. Scientific and technological work has been planned for almost seventy years in the Soviet Union on the basis of these criteria, and planning in modem science has in many respects been influenced by this experience. The forms of scientific planning which exist in the USSR have proved extremely worthwhile and are constantly being developed and improved. Increasing consideration is now being given to planning for activities connected with discoveries and new developments.

The article presents information on technology as a form of organization. In its efforts to solve the vital problems of development, society does not just increase the power of scientific knowledge, the level and volume of the technical means it uses, but it takes a new approach to organizing the generation and application of such hardware. Technological systems themselves acquire the features of a special form of organization, so-called 'organized technology.' The history of organized technology traces the development from Homo sapiens through Homo potens to Homo ducens, man who controls the scientific and technological progress he has created-a path that is eminently dialectical. By gradually eliminating the use of man's physical force and sense organs as working agents, technological advance fostered, among some people, the illusion that the role of the human factor in the processes of production was less important than it used to be. But the fact of the matter is that every new progress made by technology in replacing the physiological functions of the human being, or intensifying their effect, led ineluctably to the enhancement of man's social functions in the systems of production, in as much as its realization required new forms of social organization and every new step forward stimulated the development of special components of production which were at once organizational and technological in character.

The increased role of science accounts for much of the dynamism of the modern world. The possibility of substituting one material for another, the efficiency of new sources of energy, the advantages of automatic control of complex systems and similar problems raised by the progress of science can be solved by means of technology assessment. The social resources and premises for a solution of such problems and the many and varied consequences of the social impact of science require a social assessment. Technology assessments have always been part of applied research. At the present time, technology assessments are also increasingly being carried out by a specialized branch of research known by that name on the basis of interdisciplinary research and systems analysis of the science-technology-production-environment problem. Social assessments have always formed part of research into the problems of scientific and technological progress. In the last few decades interdisciplinary research and systems analysis have, in this field too, led to the creation of a special scientific discipline known as science policy studies.