Expression of the potyvirus coat protein mediated by recombinant vaccinia virus and assembly of potyvirus-like particles in mammalian cells.
ABSTRACT The coat protein of the potyvirus, Johnsongrass mosaic virus (JGMV), was expressed using a recombinant vaccinia virus (VV) system. Ultra-thin section electron microscopy demonstrated that the coat protein assembled into potyvirus-like particles (PVLPs) in recombinant VV infected cells. Infection of cells with two additional VV recombinants expressing coat protein plus N-terminal and N- and C-terminal extensions also resulted in the formation of PVLPs. These results suggest that the ability of VV to express the potyvirus coat protein at sufficient levels to allow PVLP formation in vitro, could make VV a suitable vector for the delivery of PVLPs displaying vaccine antigens in vivo without the need for particle purification and/or inclusion of adjuvant. Use of such a vaccine strategy would also benefit from the proven advantages of poxviruses as vaccines such as stability in a freeze dried form, resistance to environmental factors and the potential for oral administration.
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ABSTRACT: Pepper vein banding virus (PVBV) is an important virus infecting chilli pepper in south India. Earlier reports suggested it to be a distinct potyvirus. The nucleotide sequence of PVBV RNA from the 3'-end (3862 nt) was determined. Analysis of the nucleotide and deduced amino acid sequence revealed that it encompasses a partial open reading frame encoding the partial sequence of VPg, NIa-protease, NIb, coat protein (CP) and 3'-untranslated region (UTR). Comparison of the amino acid sequence of CP and the nucleotide sequence of 3'-UTR with those of other potyviruses confirmed an earlier observation that PVBV is a distinct member of the Potyvirus sub-group and it had significant similarity to a recently characterized virus infecting chilli pepper, chilli vein-banding mottle virus (CVbMV), from Thailand. The analysis showed that both PVBV and CVbMV might represent strains of the same virus. Further, the PVBV CP gene was overexpressed in E. coli, which assembled into potyvirus-like particles (PVLPs). The assembled particles were shown to encapsidate the CP mRNA.Archives of Virology 02/1999; 144(9):1679-87. DOI:10.1007/s007050050696 · 2.28 Impact Factor
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ABSTRACT: Utilities systems at oil refineries and other large industrial complexes such as pulp and paper mills or chemical plants are very big energy users that have many degrees of freedom. Manipulating these degrees of freedom with the advice of a cost based optimization program usually can result in significant savings in operating costs with small investment needs. This is particularly important within the electrical deregulation context. Since the electrical system is the main economic trade-off with a steam system, electrical deregulation provides many new challenges in order to operate the combined systems at the minimum overall cost. This paper will not describe just all the features of the software or fully explain on-line optimization technology. The objective of this work is to present some interesting facts and lessons from the experience of implementing a cost based optimization program at thirty oil refineries and petrochemical complexes, around the world, since 1997. This paper will focus on the key optimization variables and constraints in steam system optimization, how they should be handled and how the human and organizational aspects can be addressed. Several of the key optimization problems found in a typical oil refinery steam system such as boilers, extraction-condensing turbines, co-generation and turbine/motors spare drivers are discussed and how those problems can be handled properly is described.
Article: Helical viruses.[Show abstract] [Hide abstract]
ABSTRACT: Virtually all studies of structure and assembly of viral filaments have been made on plant and bacterial viruses. Structures have been determined using fiber diffraction methods at high enough resolution to construct reliable molecular models or several of the rigid plant tobamoviruses (related to tobacco mosaic virus, TMV) and the filamentous bacteriophages including Pf1 and fd. Lower-resolution structures have been determined for a number of flexible filamentous plant viruses using fiber diffraction and cryo-electron microscopy. Virions of filamentous viruses have numerous mechanical functions, including cell entry, viral disassembly, viral assembly, and cell exit. The plant viruses, which infect multicellular organisms, also use virions or virion-like assemblies for transport within the host. Plant viruses are generally self-assembling; filamentous bacteriophage assembly is combined with secretion from the host cell, using a complex molecular machine. Tobamoviruses and other plant viruses disassemble concomitantly with translation, by various mechanisms and involving various viral and host assemblies. Plant virus movement within the host also makes use of a variety of viral proteins and modified host assemblies.Advances in Experimental Medicine and Biology 01/2012; 726:631-58. DOI:10.1007/978-1-4614-0980-9_28 · 2.01 Impact Factor