Capsid composition

Based on the structural capsid protein composition, 12 PgV isolates that originate from the southern North Sea could be divided in two groups (Baudoux and Brussaard 2005). The proteins on the surface of free viruses serve as a means of virus-to-cells attachment and allow transfer of viral genomes into the host cells. Any changes in the composition of these structural proteins between viruses may affect the binding to the host cell s receptors, selecting for host range restriction. 

Newcomb et al. (1994) showed that B capsids also assemble in a cell-free system, using extracts prepared from Sf9 cells infected with recombinant baculoviruses encoding the HSV-1 capsid proteins. Similar to the observations by Tatman et al. (1994) and Thomson et al. (1994), the capsids formed in the cell-free system resembled native B capsids in morphology, sedimentation rate, protein compositions, and ability to react with HSV-Tspecific antibodies. Additional work by Newcomb et al. (1996) led to the identification of several assembly intermediates. In the cell-free system the first structures observed were partial capsids that consisted of an arclike segment of the external shell surrounding a region... 

All herpesvirus virions have a characteristic appearance (Fig. ID) with an icosahedral capsid surrounded by a thick ( 500 A) layer of protein designated the tegument (Rixon, 1993 Steven and Spear, 1997). The entire particle is enclosed by a spherical lipid envelope (Szilagyi and Berriman, 1994). The core of infectious virions is believed to consist exclusively of the double-stranded DNA genome without any associated protein (Booy et al, 1991 Zhou et al, 1999). The structures of the tegument and envelope are poorly understood as they are indeterminate in both size and composition and have a limited symmetrical relationship to the capsid (Chen et al, 1999 Zhou et al, 1999). 

Wingfield, P. T., Stahl, S. J., Williams, R. W., and Steven, A. G. (1995). Hepatitis core antigen produced in Escherichia coli subunit composition, conformational analysis, and in vitro capsid assembly. Biochemistry 34, 4919-4932. 

Johnson, Fig. 3. A composite of the capsid of paricoto virus (a nodavirus related to flock house virus) produced by electron cryomicroscopy and the packaged nucleic acid produced from the X-ray structure. The regions of the capsid protein that interact with the RNA are also shown from the X-ray structure (Tang et al, 2001). 

Assembly of picornaviruses proceeds via protomers of VP1, VP3 and VP0 (the latter is an initial composite of VP2 and VP4) and then via pentamers of these protomers to mature viruses. The final step involves inclusion of the RNA into empty capsids or partially assembled shells with simultaneous cleavage of VP0 into VP2 and VP4. Conversely, in vitro disassembly, produced by mild destruction, proceeds via the expul-... 

Hu and collaborators isolated a new indole-pyrazine alkaloid, colletotri-chumine A (97), with a novel Ci6N3-type skeleton from Colletotrichum capsid, a pathogenic fungus and a newly discovered source of natural products with heretofore unprecedented structural compositions (F ure 15) (14TL6093). 

III.Purification and amino acid compositions of the major capsid polypeptides. Virology, (l975)f 228-235 ... 

Phillips BA, Fennel R Polypeptide composition of poliovirions, naturally occurring empty capsids, and 14S precursor particles. J Virol 12 291-29. 

C. Uetrecht et al.. High-resolution mass spectrometry of viral assemblies molecular composition and stability of dimorphic hepatitis B virus capsids. Proc. Natl. Acad. Sci. USA 105, 9216-9220 (2008)... 

Fig. 18 Composite micelles consisting of antisense oligonucleotides and (a) viral capsids or (b) synthetic polymers, (a) Micelles of DNA amphiphiles loaded with either small hydrophobic compounds top left) or with hydrophilic compounds by hybridization top right) were used to template virus capsid formation at neutral pH. TEM images show micelles incorporated into virus capsids with T = 1 or 2 geometry and an empty capsid formed at pH 5.0 as control inset). Scale bars 40 nm. (b) Representation of a blend micelle. Diblock DNA copolymer PPO-h-DNA was mixed with a triblock copolymer Pluronic (PEO-h-PPO-h-PEO) composed of the same hydrophobic block, PPO [21] (figure reproduced with permission of Royal Society of Chemistry)...

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