scholarly journals Anchoring of a hydrophobic heptapeptide (AFILPTG) on silica facilitates peptide unfolding at the abiotic-biotic interface

2021 ◽  
Author(s):  
Victor V Volkov ◽  
Hendrik Heinz ◽  
Carole Celia Perry
Keyword(s):  
Capsid Protein ◽  
Negative Charge ◽  
Silica Particles ◽  
Binding Activity ◽  
Phage Capsid

A hydrophobic heptapeptide, sequence AFILPTG, as part of a phage capsid protein binds effectively to silica particles carrying negative charge. Here, we explore the silica binding activity of the sequence...

scholarly journals Structural Analysis of Jumbo Coliphage phAPEC6

2020 ◽  
Vol 21 (9) ◽  
pp. 3119 ◽  
Author(s):  
Jeroen Wagemans ◽  
Jessica Tsonos ◽  
Dominique Holtappels ◽  
Kiandro Fortuna ◽  
Jean-Pierre Hernalsteens ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Capsid Protein ◽  
Tem Analysis ◽  
Host Interaction ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
Tail Sheath ◽  
Associated Proteins ◽  
Contractile Tail ◽  
Phage Capsid

The phAPEC6 genome encodes 551 predicted gene products, with the vast majority (83%) of unknown function. Of these, 62 have been identified as virion-associated proteins by mass spectrometry (ESI-MS/MS), including the major capsid protein (Gp225; present in 1620 copies), which shows a HK97 capsid protein-based fold. Cryo-electron microscopy experiments showed that the 350-kbp DNA molecule of Escherichia coli virus phAPEC6 is packaged in at least 15 concentric layers in the phage capsid. A capsid inner body rod is also present, measuring about 91 nm by 18 nm and oriented along the portal axis. In the phAPEC6 contractile tail, 25 hexameric stacked rings can be distinguished, built of the identified tail sheath protein (Gp277). Cryo-EM reconstruction reveals the base of the unique hairy fibers observed during an initial transmission electron microscopy (TEM) analysis. These very unusual filaments are ordered at three annular positions along the contractile sheath, as well as around the capsid, and may be involved in host interaction.

Viral fitness and antigenic determinants of porcine parvovirus at the amino acid level of the capsid protein

2021 ◽  
Author(s):  
André Felipe Streck ◽  
Cláudio Wageck Canal ◽  
Uwe Truyen
Keyword(s):  
Amino Acid ◽  
Capsid Protein ◽  
Immune Escape ◽  
Amino Acid Level ◽  
Binding Activity ◽  
Viral Fitness ◽  
Antigenic Determinants ◽  
Amino Acid Substitutions ◽  
Porcine Parvovirus ◽  
Predominant Factor

Since 2001, strains of porcine parvovirus (PPV), designated 27a -like strains, were observed in Europe, suggesting a predominance of these viruses over older strains. The reasons for the obvious evolutionary advantage are unknown. Here, a series of mutants containing amino acid replacements found in the predominant field strains were generated in a PPV-NADL2 background and their impact on replication efficiency and antibody binding activity was determined. Some amino acid substitutions observed in the 27a- like strains significantly increased viral fitness and decreased neutralization activity of sera raised against commercial vaccines and old virus strains (e.g. NADL2). These mutant viruses and a monoclonal antibody raised against a classical PPV strain defined an 27a-specific neutralizing epitope around amino acid 228 of the capsid protein VP2. Based on the analysis of the mutant viruses, it is hypothesized that the predominant factor for the global spread of the PPV-27a strain substitutions is an increased viral fitness of the 27a- like viruses, possibly supported by a partial immune selection. This is reminiscent to the evolution of canine parvovirus and worldwide replacement of the original virus by the so-called new antigenic types. Importance Porcine parvovirus is one of the most important causes of reproductive failure in swine. Recently, despite the continuous use of vaccines, “new” strains emerged, leading to the hypothesis that the emergence of new amino acid substitutions could be a viral adaptation to the immune response against the commercial vaccines. Our results indicate the amino acid substitutions observed in the 27a -like strains can modify viral fitness and antigenicity. However, an absolute immune escape was not evident.

Characterization of monoclonal antibodies to hepatitis E virus (HEV) capsid protein and identification of binding activity

2007 ◽  
Vol 14 (5) ◽  
pp. 555-563 ◽  
Author(s):  
Junkun He ◽  
Robert A. Kuschner ◽  
Vincent Dewar ◽  
Pierre Voet ◽  
Ludmila V. Asher ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Binding Activity

scholarly journals The TolQRA Proteins Are Required for Membrane Insertion of the Major Capsid Protein of the Filamentous Phage f1 during Infection

1998 ◽  
Vol 180 (7) ◽  
pp. 1723-1728 ◽  
Author(s):  
Eva Marie Click ◽  
Robert E. Webster
Keyword(s):  
Capsid Protein ◽  
Phage Particle ◽  
Cytoplasmic Membrane ◽  
Major Capsid Protein ◽  
Infection Process ◽  
Dna Transfer ◽  
Filamentous Phage ◽  
Membrane Insertion ◽  
Phage Dna ◽  
Phage Capsid

ABSTRACT Infection of Escherichia coli by the filamentous bacteriophage f1 is initiated by interaction of the end of the phage particle containing the gene III protein with the tip of the F conjugative pilus. This is followed by the translocation of the phage DNA into the cytoplasm and the insertion of the major phage capsid protein, pVIII, into the cytoplasmic membrane. DNA transfer requires the chromosomally encoded TolA, TolQ, and TolR cytoplasmic membrane proteins. By using radiolabeled phages, it can be shown that no pVIII is inserted into the cytoplasmic membrane when the bacteria contain null mutations in tolQ, -R and -A. The rate of infection can be varied by using bacteria expressing various mutant TolA proteins. Analysis of the infection process in these strains demonstrates a direct correlation between the rate of infection and the incorporation of infecting bacteriophage pVIII into the cytoplasmic membrane.

Analysis of DNA-Binding Activity of the JC Virus Minor Capsid Protein VP2

2003 ◽  
Vol 9 (2) ◽  
pp. 21-24
Author(s):  
Yih-Leh Huang ◽  
Meilin Wang ◽  
Wei-Chih Ou ◽  
Chiung-Yau Fung ◽  
Li-Sheng Chen ◽  
...  
Keyword(s):  
Dna Binding ◽  
Capsid Protein ◽  
Jc Virus ◽  
Binding Activity ◽  
Minor Capsid Protein ◽  
Dna Binding Activity

scholarly journals Multiple Activities Associated with the Capsid Protein of Satellite Panicum Mosaic Virus Are Controlled Separately by the N- and C-Terminal Regions

2008 ◽  
Vol 21 (5) ◽  
pp. 613-621 ◽  
Author(s):  
Dong Qi ◽  
Karen-Beth G. Scholthof
Keyword(s):  
Mosaic Virus ◽  
Capsid Protein ◽  
Rna Binding ◽  
Binding Activity ◽  
Multiple Roles ◽  
Virion Assembly ◽  
Biologically Relevant ◽  
C Terminus ◽  
Rna Accumulation ◽  
Interfering Rna

The 17-kDa capsid protein (CP) of satellite panicum mosaic virus (SPMV) contains a distinct N-terminal arginine-rich motif (N-ARM) which is required for SPMV virion assembly and the activity of SPMV CP to promote systemic accumulation of its cognate RNA. The present study indicates that SPMV CP also is involved in SPMV RNA accumulation in inoculated leaves and that this activity is also dependent on a functional N-ARM. In addition, deletions of a C-terminal region abolish virion assembly and impair SPMV RNA accumulation in both inoculated and systemic leaves. Unlike the N-ARM mutations, substantial deletions of the SPMV CP C-terminus do not affect SPMV RNA binding activity. Interestingly, SPMV CP also binds Panicum mosaic virus genomic RNA via N-ARM-mediated CP:RNA interactions. Mutations of the N-ARM and the C-terminal regions significantly reduce SPMV CP titers and result in symptom attenuation. In contrast, virions were not associated per se with symptom exacerbation or successful SPMV RNA accumulation. The results show the existence of a correlation between N- and C-termini-mediated contributions for CP accumulation, symptom induction, defective-interfering RNA accumulation, and temperature sensitivity of SPMV RNA maintenance. The data provide further evidence that SPMV CP has multiple roles during infection, which might involve the formation of nonvirion CP:RNA complexes whose stability is controlled in a biologically relevant manner by the N- and C-termini of the CP.

scholarly journals Distinct binding sites for zinc and double-stranded RNA in the reovirus outer capsid protein sigma 3.

1988 ◽  
Vol 8 (1) ◽  
pp. 273-283 ◽  
Author(s):  
L A Schiff ◽  
M L Nibert ◽  
M S Co ◽  
E G Brown ◽  
B N Fields
Keyword(s):  
Transcription Factor ◽  
Capsid Protein ◽  
Binding Activity ◽  
Zinc Binding ◽  
Outer Capsid Protein ◽  
Double Stranded Rna ◽  
Transcription Factor Iiia ◽  
Terminal Fragment ◽  
Dsrna Binding ◽  
Outer Capsid

By atomic absorption analysis, we determined that the reovirus outer capsid protein sigma 3, which binds double-stranded RNA (dsRNA), is a zinc metalloprotein. Using Northwestern blots and a novel zinc blotting technique, we localized the zinc- and dsRNA-binding activities of sigma 3 to distinct V8 protease-generated fragments. Zinc-binding activity was contained within an amino-terminal fragment that contained a transcription factor IIIA-like zinc-binding sequence, and dsRNA-binding activity was associated with a carboxy-terminal fragment. By these techniques, new zinc- and dsRNA-binding activities were also detected in reovirus core proteins. A sequence similarity was observed between the catalytic site of the picornavirus proteases and the transcription factor IIIA-like zinc-binding site within sigma 3. We suggest that the zinc- and dsRNA-binding activities of sigma 3 may be important for its proposed regulatory effects on viral and host cell transcription and translation.

scholarly journals Relationship of the Molecular Size and Charge Density of Polyoxometalates to Their anti-gp120-CD4-binding Activity

1994 ◽  
Vol 5 (6) ◽  
pp. 410-414 ◽  
Author(s):  
D. A. Judd ◽  
R. F. Schinazi ◽  
C. L. Hill
Keyword(s):  
Molecular Weight ◽  
Charge Density ◽  
Negative Charge ◽  
Molecular Size ◽  
Binding Activity ◽  
Weak Correlation ◽  
Binding Inhibition ◽  
Negative Charge Density ◽  
Relationship Of ◽  
Hiv 1

The ability of several classes of polyoxometalates to inhibit the interaction between HIV-1 gp120 and CD4 was assessed. No clear relationship was found between binding inhibition and the negative charge density on the anion portion of the polyoxometalate. However, a weak correlation was found with molecular size. There was a molecular weight threshold of 3800 g mol-1 above which no significant increase in potency was gained; the binding inhibition was nearly quantitative above this molecular weight.

Phage capsid protein-directed MnO2 nanosheets with peroxidase-like activity for spectrometric biosensing and evaluation of antioxidant behaviour

2017 ◽  
Vol 53 (37) ◽  
pp. 5216-5219 ◽  
Author(s):  
Lei Han ◽  
Pei Liu ◽  
Haijiao Zhang ◽  
Feng Li ◽  
Aihua Liu
Keyword(s):  
Capsid Protein ◽  
Mno2 Nanosheets ◽  
Phage Capsid
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