Roles of three amino acids of capsid proteins in mink enteritis parvovirus replication

2016 ◽  
Vol 222 ◽  
pp. 24-28 ◽  
Author(s):  
Yaping Mao ◽  
Jun Su ◽  
Jigui Wang ◽  
Xiaomei Zhang ◽  
Qiang Hou ◽  
...  
Keyword(s):  
Amino Acids ◽  
Capsid Proteins

scholarly journals Neutralization Mechanism of a Monoclonal Antibody Targeting a Porcine Circovirus Type 2 Cap Protein Conformational Epitope

2020 ◽  
Vol 94 (9) ◽  
Author(s):  
Liping Huang ◽  
Zhenzhao Sun ◽  
Deli Xia ◽  
Yanwu Wei ◽  
Encheng Sun ◽  
...  
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Neutralizing Antibodies ◽  
Vaccine Design ◽  
Binding Mode ◽  
Porcine Circovirus Type ◽  
Therapeutic Antibody ◽  
Capsid Proteins ◽  
Porcine Circovirus

ABSTRACT Porcine circovirus type 2 (PCV2) is an important pathogen in swine herds, and its infection of pigs has caused severe economic losses to the pig industry worldwide. The capsid protein of PCV2 is the only structural protein that is associated with PCV2 infection and immunity. Here, we report a neutralizing monoclonal antibody (MAb), MAb 3A5, that binds to intact PCV2 virions of the PCV2a, PCV2b, and PCV2d genotypes. MAb 3A5 neutralized PCV2 by blocking viral attachment to PK15 cells. To further explore the neutralization mechanism, we resolved the structure of the PCV2 virion in complex with MAb 3A5 Fab fragments by using cryo-electron microscopy single-particle analysis. The binding sites were located at the topmost edges around 5-fold icosahedral symmetry axes, with each footprint covering amino acids from two adjacent capsid proteins. Most of the epitope residues (15/18 residues) were conserved among 2,273 PCV2 strains. Mutations of some amino acids within the epitope had significant effects on the neutralizing activity of MAb 3A5. This study reveals the molecular and structural bases of this PCV2-neutralizing antibody and provides new and important information for vaccine design and therapeutic antibody development against PCV2 infections. IMPORTANCE PCV2 is associated with several clinical manifestations collectively known as PCV2-associated diseases (PCVADs). Neutralizing antibodies play a crucial role in the prevention of PCVADs. We demonstrated previously that a MAb, MAb 3A5, neutralizes the PCV2a, PCV2b, and PCV2d genotypes with different degrees of efficiency, but the underlying mechanism remains elusive. Here, we report the neutralization mechanism of this MAb and the structure of the PCV2 virion in complex with MAb 3A5 Fabs, showing a binding mode in which one Fab interacted with more than two loops from two adjacent capsid proteins. This binding mode has not been observed previously for PCV2-neutralizing antibodies. Our work provides new and important information for vaccine design and therapeutic antibody development against PCV2 infections.

scholarly journals Nucleotide sequences of segments 1, 3 and 4 of the genome of Bombyx mori cypovirus 1 encoding putative capsid proteins VP1, VP3 and VP4, respectively

2002 ◽  
Vol 83 (6) ◽  
pp. 1477-1482 ◽  
Author(s):  
Kyoji Hagiwara ◽  
Shujing Rao ◽  
Simon W. Scott ◽  
Gerald R. Carner
Keyword(s):  
Amino Acids ◽  
Bombyx Mori ◽  
Nucleotide Sequences ◽  
Open Reading Frame ◽  
Capsid Proteins ◽  
Structural Proteins ◽  
Reading Frame ◽  
The Family ◽  
Molecular Masses ◽  
Rice Ragged Stunt Virus

The complete nucleotide sequences of genomic segments S1, S3 and S4 from Bombyx mori cypovirus 1 (BmCPV-1) have been determined. The segments consisted of 4190, 3846 and 3262 nucleotides encoding putative proteins of 1333, 1239 and 1058 amino acids with molecular masses of approximately 148, 140 and 120 kDa (p148, p140 and p120, respectively). All segments possess a single open reading frame. Homology searches showed that all three proteins have homologies to proteins of Rice ragged stunt virus, a member of the genus Oryzavirus within the family Reoviridae. Partial homologies of p140 to structural proteins in other viruses were also found. The predicted molecular masses and the homologies with structural proteins in other viruses lead us to suggest that S1, S3 and S4 encode the capsid proteins VP1, VP3, and VP4, respectively, of BmCPV-1.

scholarly journals The Abundant Nuclear Enzyme PARP Participates in the Life Cycle of Simian Virus 40 and Is Stimulated by Minor Capsid Protein VP3

2003 ◽  
Vol 77 (7) ◽  
pp. 4273-4282 ◽  
Author(s):  
Ariela Gordon-Shaag ◽  
Yael Yosef ◽  
Mahmoud Abd El-Latif ◽  
Ariella Oppenheim
Keyword(s):  
Amino Acids ◽  
Life Cycle ◽  
Capsid Protein ◽  
Membrane Integrity ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Capsid Proteins ◽  
Dependent Manner ◽  
Minor Capsid Protein ◽  
Stimulation Of

ABSTRACT The abundant nuclear enzyme poly(ADP-ribose) polymerase (PARP) functions in DNA damage surveillance and repair and at the decision between apoptosis and necrosis. Here we show that PARP binds to simian virus 40 (SV40) capsid proteins VP1 and VP3. Furthermore, its enzymatic activity is stimulated by VP3 but not by VP1. Experiments with purified mutant proteins demonstrated that the PARP binding domain in VP3 is localized to the 35 carboxy-terminal amino acids, while a larger peptide of 49 amino acids was required for full stimulation of its activity. The addition of 3-aminobenzamide (3-AB), a known competitive inhibitor of PARP, demonstrated that PARP participates in the SV40 life cycle. The titer of SV40 propagated on CV-1 cells was reduced by 3-AB in a dose-dependent manner. Additional experiments showed that 3-AB did not affect viral DNA replication or capsid protein production. PARP did not modify the viral capsid proteins in in vitro poly(ADP-ribosylation) assays, implying that it does not affect SV40 infectivity. On the other hand, it greatly reduced the magnitude of the host cytopathic effects, a hallmark of SV40 infection. Additional experiments suggested that the stimulation of PARP activity by VP3 leads the infected cell to a necrotic pathway, characterized by the loss of membrane integrity, thus facilitating the release of mature SV40 virions from the cells. Our studies identified a novel function of the minor capsid protein VP3 in the recruitment of PARP for the SV40 lytic process.

scholarly journals Mapping of linear epitopes on the capsid proteins of swine vesicular disease virus using monoclonal antibodies

2002 ◽  
Vol 83 (6) ◽  
pp. 1387-1395 ◽  
Author(s):  
Belén Borrego ◽  
Juan Antonio García-Ranea ◽  
Alastair Douglas ◽  
Emiliana Brocchi
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibodies ◽  
Disease Virus ◽  
Diagnostic Methods ◽  
Capsid Proteins ◽  
Antigenic Structure ◽  
Virus Infectivity ◽  
Swine Vesicular Disease Virus ◽  
Linear Epitopes ◽  
Vesicular Disease

The antigenic linear map of swine vesicular disease virus (SVDV) has been studied using a repertoire of monoclonal antibodies (mAbs) raised against a recombinant SVDV polyprotein, P1. Peptide-scanning analyses, cross-reactivity studies with homologous and heterologous viruses and predicted location on a computer-generated three-dimensional model of the capsid proteins have allowed the identification of five main linear sites. Two sites, the N terminus of VP3 and amino acids 51–60 on VP1, correspond to internal areas, conserved not only between SVDV isolates but also in the related enterovirus coxsackievirus B5. In contrast, three other regions, amino acids 142–161 of VP2, 61–70 of VP3 and the C terminus of VP1, are exposed on the external face of the capsid and subjected to antigenic variation, even among different SVDV isolates. Further minor sites that were antigenically conserved were identified on VP4. In contrast with conformational sites described previously, none of the linear epitopes identified in this work is involved in neutralization of virus infectivity and post-infection swine sera did not inhibit the binding of mAbs with the relevant epitopes. Both of these observations suggest that linear epitopes are poorly immunogenic in pigs. The characterization of linear sites has contributed to a better understanding of the antigenic structure of SVDV and mAbs used to this purpose may provide a useful tool for the improvement of diagnostic methods, such as antigen detection systems, and analyses of the antigenic profile of SVDV isolates.

scholarly journals The Impact of Capsid Proteins on Virus Removal and Inactivation during Water Treatment Processes

2015 ◽  
Vol 8s2 ◽  
pp. MBI.S31441 ◽  
Author(s):  
Brooke K. Mayer ◽  
Yu Yang ◽  
Daniel W. Gerrity ◽  
Morteza Abbaszadegan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hydroxyl Radicals ◽  
Capsid Proteins ◽  
Virus Inactivation ◽  
Virus Removal ◽  
Titanium Dioxide Photocatalysis ◽  
Genomic Damage ◽  
Virus Size ◽  
The Impact

This study examined the effect of the amino acid composition of protein capsids on virus inactivation using ultraviolet (UV) irradiation and titanium dioxide photocatalysis, and physical removal via enhanced coagulation using ferric chloride. Although genomic damage is likely more extensive than protein damage for viruses treated using UV, proteins are still substantially degraded. All amino acids demonstrated significant correlations with UV susceptibility. The hydroxyl radicals produced during photocatalysis are considered nonspecific, but they likely cause greater overall damage to virus capsid proteins relative to the genome. Oxidizing chemicals, including hydroxyl radicals, preferentially degrade amino acids over nucleotides, and the amino acid tyrosine appears to strongly influence virus inactivation. Capsid composition did not correlate strongly to virus removal during physicochemical treatment, nor did virus size. Isoelectric point may play a role in virus removal, but additional factors are likely to contribute.

scholarly journals A −1 Ribosomal Frameshift in the Transcript That Encodes the Major Head Protein of Bacteriophage A2 Mediates Biosynthesis of a Second Essential Component of the Capsid

2004 ◽  
Vol 186 (6) ◽  
pp. 1714-1719 ◽  
Author(s):  
Pilar García ◽  
Isabel Rodríguez ◽  
Juan E. Suárez
Keyword(s):  
Amino Acids ◽  
Mitomycin C ◽  
Proteolytic Processing ◽  
The Other ◽  
Capsid Proteins ◽  
Ribosomal Frameshift ◽  
Drastic Reduction ◽  
Stem Loop ◽  
Head Protein ◽  
Slippery Sequence

ABSTRACT The two major capsid proteins of Lactobacillus bacteriophage A2 share their amino termini. The smaller of these (gp5A) results from translation of orf5 and proteolytic processing after residue 123. The larger form (gp5B) originates through a −1 ribosomal frameshift at the penultimate codon of orf5 mRNA, resulting in a product that is 85 amino acids longer than gp5A. Frameshifting needs two cis-acting elements: a slippery region with the sequence C CCA AAA (0 frame), and a stem-loop that begins 9 nucleotides after the end of the slippery sequence. Mutations introduced in the slippery sequence suppress the frameshift. Similarly, deletion of the second half of the stem-loop results in drastic reduction of frameshifting. Both gp5A and gp5B appear to be essential for phage viability, since lysogens harboring prophages that produce only one or the other protein become lysed upon induction with mitomycin C, though no viable phage progeny are observed.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

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