scholarly journals The VP1 N-Terminal Sequence of Canine Parvovirus Affects Nuclear Transport of Capsids and Efficient Cell Infection

2002 ◽  
Vol 76 (4) ◽  
pp. 1884-1891 ◽  
Author(s):  
Maija Vihinen-Ranta ◽  
Dai Wang ◽  
Wendy S. Weichert ◽  
Colin R. Parrish
Keyword(s):  
Amino Acids ◽  
Nuclear Transport ◽  
Canine Parvovirus ◽  
High Concentration ◽  
Cell Infection ◽  
Unique Region ◽  
Basic Amino Acids ◽  
Conserved Sequence ◽  
N Terminus ◽  
Vp1 Capsid Protein

ABSTRACT The unique N-terminal region of the parvovirus VP1 capsid protein is required for infectivity by the capsids but is not required for capsid assembly. The VP1 N terminus contains a number of groups of basic amino acids which resemble classical nuclear localization sequences, including a conserved sequence near the N terminus comprised of four basic amino acids, which in a peptide can act to transport other proteins into the cell nucleus. Testing with a monoclonal antibody recognizing residues 2 to 13 of VP1 (anti-VP1-2-13) and with a rabbit polyclonal serum against the entire VP1 unique region showed that the VP1 unique region was not exposed on purified capsids but that it became exposed after treatment of the capsids with heat (55 to 75°C), or urea (3 to 5 M). A high concentration of anti-VP1-2-13 neutralized canine parvovirus (CPV) when it was incubated with the virus prior to inoculation of cells. Both antibodies blocked infection when injected into cells prior to virus inoculation, but neither prevented infection by coinjected infectious plasmid DNA. The VP1 unique region could be detected 4 and 8 h after the virus capsids were injected into cells, and that sequence exposure appeared to be correlated with nuclear transport of the capsids. To examine the role of the VP1 N terminus in infection, we altered that sequence in CPV, and some of those changes made the capsids inefficient at cell infection.

scholarly journals Genome organization of the densovirus from Bombyx mori (BmDNV-1) and enzyme activity of its capsid

2001 ◽  
Vol 82 (11) ◽  
pp. 2821-2825 ◽  
Author(s):  
Y. Li ◽  
Z. Zádori ◽  
H. Bando ◽  
R. Dubuc ◽  
G. Fédière ◽  
...  
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Bombyx Mori ◽  
Genome Sequence ◽  
Genome Organization ◽  
Phospholipase A ◽  
Sequence Motifs ◽  
Unique Region ◽  
Conserved Sequence

Bombyx mori densovirus (BmDNV-1), on the basis of the previously reported genome sequence, constitutes by itself a separate genus (Iteravirus) within the Densovirinae subfamily of parvoviruses. Inconsistencies in the genome organization, however, necessitated its reassessment. The genome sequence of new clones was determined and resulted in a completely different genome organization. The corrected sequence also contained conserved sequence motifs found in other parvoviruses. Some amino acids in the highly conserved domain in the unique region of VP1 were shared by critical amino acids in the catalytic site and Ca2+-binding loop of secreted phospholipase A2, such as from snake and bee venoms. Expression of this domain and determination of enzyme activity demonstrated that capsids have a phospholipase A2 activity thus far unknown to occur in viruses. This viral phospholipase A2, which is required shortly after entry into the cell, showed a substrate preference for phosphatidylethanolamine and phosphatidylcholine over phosphatidylinositol.

scholarly journals Sequence Properties of the MAAP Protein and of the VP1 Capsid Protein of Adeno-Associated Viruses

2020 ◽  
Author(s):  
David G. Karlin
Keyword(s):  
Amino Acids ◽  
Gene Therapy ◽  
Alpha Helix ◽  
Start Codon ◽  
Disulfide Bridges ◽  
Unknown Mechanism ◽  
Muscle Tissues ◽  
N Terminus ◽  
Gene Therapy Vectors ◽  
Vp1 Capsid Protein

Adeno-associated viruses (AAVs, genus dependoparvovirus) are promising gene therapy vectors. In strains AAV1-12, the capsid gene VP1 encodes a recently discovered protein, MAAP, in an overlapping frame. MAAP binds the cell membrane by an unknown mechanism. We discovered that MAAP is also encoded in bovine AAV and in porcine AAVs (which have shown promise for gene transfer into muscle tissues), in which it is probably translated from a non-canonical start codon. MAAP is predicted to be mostly disordered except for a predicted C-terminal, membrane-binding amphipathic α-helix. MAAP has a highly unusual composition. In particular, it lacks internal methionines, and is devoid of tyrosines in most strains. Unexpectedly, we discovered that the N-terminus of VP1 also lacks several amino acids. In all AAVs that encode MAAP, the first 200 aas of VP1 are devoid of internal methionines, probably owing to a selection against ATG codons that could prevent translation of MAAP and of capsid isoforms (VP2, VP3). The N-terminus of VP1 also lacks cysteines, likely to avoid the formation of disulfide bridges when it becomes exposed outside of the capsid during post-endocytic trafficking. Finally, the region common to VP1 and VP2 lacks tyrosine in the vast majority of AAVs that encode MAAP. Avoiding these "forbidden" aas in MAAP and VP1 when creating recombinant AAV capsids might increase the efficiency of capsid design. Conversely, the presence of "forbidden" aas in some rare strains probably indicates that they have unusual properties that could help us understand the viral cycle.

scholarly journals Genetic Organization of Plasmid ColJs, Encoding Colicin Js Activity, Immunity, and Release Genes

2001 ◽  
Vol 183 (13) ◽  
pp. 3949-3957 ◽  
Author(s):  
David Šmajs ◽  
George M. Weinstock
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fusion Protein ◽  
Molecular Mass ◽  
Open Reading Frames ◽  
Unique Region ◽  
Immunity Protein ◽  
N Terminus ◽  
Reading Frames ◽  
Histidine Tag

ABSTRACT The 5.2-kb ColJs plasmid of a colicinogenic strain ofShigella sonnei (colicin type 7) was isolated and sequenced. pColJs was partly homologous to pColE1 and to pesticin-encoding plasmid pPCP1, mainly in the rep,mob, and cer regions. A 1.2-kb unique region of pColJs showed significantly different G+C content (34%) compared to the rest of pColJs (53%). Within the unique region, seven open reading frames (ORFs) were identified. ORF94 was shown to code for colicin Js activity (cja), a 94-amino-acid polypeptide (molecular mass, 10.4 kDa); ORF129 (cji) was shown to code for the 129-amino-acid colicin Js immunity protein (molecular mass, 14.3 kDa); and ORF65 was shown to be involved in colicin Js release by producer bacteria (cjl) coding for a 65-amino-acid polypeptide (molecular mass, 7.5 kDa). In contrast to the gene order in other colicin operons, the cjl gene was found upstream from cja. Moreover, the promoter upstream from cjl was similar to promoters described upstream from several colicin activity genes. The cji gene was found to be located downstream from cja with a transcription polarity opposite to that of the cjl andcja genes. The cja, cji, and cjl genes were not similar to other known colicin genes. Colicin Js was purified as an inactive fusion protein with an N-terminal histidine tag. Activity of the purified fusion form of colicin Js was restored after cleavage of the amino acids fused to the colicin Js N terminus.

NRD convertase: a putative processing endoprotease associated with the axoneme and the manchette in late spermatids

1996 ◽  
Vol 109 (11) ◽  
pp. 2737-2745 ◽  
Author(s):  
V. Chesneau ◽  
A. Prat ◽  
D. Segretain ◽  
V. Hospital ◽  
A. Dupaix ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Germ Cells ◽  
Basic Amino Acids ◽  
N Terminus ◽  
Arginine Residues ◽  
Marked Accumulation ◽  
Low Levels ◽  
Morphological Transformations ◽  
Microtubular Structures

N-arginine dibasic convertase is a novel metalloendopeptidase which selectively cleaves at the N terminus of arginine residues in paired basic amino acids. Although present in brain and several other tissues, NRD convertase is particularly abundant in testis, where its expression appeared to be restricted to germ cells. Low levels of both mRNA and its corresponding protein were detected early in spermatogenesis. However, a marked accumulation of the protein was observed during late steps (14 to 19) of spermiogenesis. By electron microscopy, the NRD convertase immunoreactivity was localized in the cytoplasm of elongating and elongated spermatids, with a noticeable concentration at the level of two microtubular structures, i.e. the manchette and the axoneme. These observations strongly support the hypothesis that NRD convertase is involved in processing events potentially associated with the morphological transformations occurring during spermiogenesis.

scholarly journals Combinations of Two Capsid Regions Controlling Canine Host Range Determine Canine Transferrin Receptor Binding by Canine and Feline Parvoviruses

2003 ◽  
Vol 77 (18) ◽  
pp. 10099-10105 ◽  
Author(s):  
Karsten Hueffer ◽  
Lakshman Govindasamy ◽  
Mavis Agbandje-McKenna ◽  
Colin R. Parrish
Keyword(s):  
Amino Acids ◽  
Host Range ◽  
Receptor Binding ◽  
Transferrin Receptor ◽  
Canine Parvovirus ◽  
Binding Property ◽  
Cell Infection ◽  
Feline Panleukopenia Virus ◽  
Low Levels

ABSTRACT Feline panleukopenia virus (FPV) and its host range variant, canine parvovirus (CPV), can bind the feline transferrin receptor (TfR), while only CPV binds to the canine TfR. Introducing two CPV-specific changes into FPV (at VP2 residues 93 and 323) endowed that virus with the canine TfR binding property and allowed canine cell infection, although neither change alone altered either property. In CPV the reciprocal changes of VP2 residue 93 or 323 to the FPV sequences individually resulted in modest reductions in infectivity for canine cells. Changing both residues in CPV to the FPV amino acids blocked the canine cell infection, but that virus was still able to bind the canine TfR at low levels. This shows that both CPV-specific changes control canine TfR binding but that binding is not always sufficient to mediate infection.

Does the polyamine carrier system absorb basic amino acids?

2001 ◽  
Vol 120 (5) ◽  
pp. A142-A142
Author(s):  
J GASKEY ◽  
E SEIDEL
Keyword(s):  
Amino Acids ◽  
Carrier System ◽  
Basic Amino Acids

Chemical Composition and Metal Speciation in Porewaters from the Upper Qu’Appelle River Basin, Saskatchewan

1993 ◽  
Vol 28 (1) ◽  
pp. 83-110 ◽  
Author(s):  
Richard E. Farrell ◽  
Jae E. Yang ◽  
P. Ming Huang ◽  
Wen K. Liaw
Keyword(s):  
Amino Acids ◽  
Trace Metal ◽  
River Basin ◽  
Drainage Basin ◽  
Metal Speciation ◽  
Anthropogenic Activities ◽  
High Concentration ◽  
Metal Concentrations ◽  
Carbonate Equilibria ◽  
The Impact

Abstract Porewater samples from the upper Qu’Appelle River basin in Saskatchewan, Canada, were analyzed to obtain metal, inorganic ligand and amino add profiles. These data were used to compute the aqueous speciation of the metals in each porewater using the computer program GEOCHEM-PC. The porewaters were classified as slightly to moderately saline. Metal concentrations reflected both the geology of the drainage basin and the impact of anthropogenic activities. Whereas K and Na were present almost entirely as the free aquo ions, carbonate equilibria dominated the speciation of Ca. Mg and Mn (the predominant metal ligand species were of the type MCO3 (s). MCO30. and MHCO3+). Trace metal concentrations were generally within the ranges reported for non-polluted freshwater systems. Whereas the speciation of the trace metals Cr(III) and Co(II) was dominated by carbonate equilibria, Hg(II)-, Zn(II)- and Fe(II)-speciation was dominated by hydroxy-metal complexes of the type M(OH)+ and M(OH)2°. The speciation of Fe(III) was dominated by Fe(OH)3 (s). In porewaters with high chloride concentrations (> 2 mM), however, significant amounts of Hg(II) were bound as HgCl20 and HgClOH0. The aqueous speciation of Al was dominated by Al(OH)4− and Al2Si2O4(OH)6 (s). Total concentrations of dissolved free amino acids varied from 15.21 to 25.17 umole L−1. The most important metal scavenging amino acids were histidine (due to high stability constants for the metal-histidine complexes) and tryptophan (due to its relatively high concentration in the porewaters. i.e., 5.96 to 7.73 umole L−1). Secondary concentrations of various trace metal-amino add complexes were computed for all the porewaters, but metal-amino acid complexes dominated the speciation of Cu(II) in all the porewaters and Ni(II) in two of the porewaters.

Peptide vaccine against canine parvovirus: identification of two neutralization subsites in the N terminus of VP2 and optimization of the amino acid sequence.

1995 ◽  
Vol 69 (11) ◽  
pp. 7274-7277 ◽  
Author(s):  
J I Casal ◽  
J P Langeveld ◽  
E Cortés ◽  
W W Schaaper ◽  
E van Dijk ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Peptide Vaccine ◽  
Canine Parvovirus ◽  
N Terminus

Post-proline endopeptidase, further characterization of the enzyme from pig kidneys

1984 ◽  
Vol 49 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
Karel Hauzer ◽  
Tomislav Barth ◽  
Linda Servítová ◽  
Karel Jošt
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Relative Molecular Mass ◽  
Enzyme Molecule ◽  
Thiol Compounds ◽  
Modified Method ◽  
N Terminus

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.

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