scholarly journals Capsid protein identification and analysis of mature Triatoma virus (TrV) virions and naturally occurring empty particles

Virology ◽  
2011 ◽  
Vol 409 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Jon Agirre ◽  
Kerman Aloria ◽  
Jesus M. Arizmendi ◽  
Ibón Iloro ◽  
Félix Elortza ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Protein Identification ◽  
Naturally Occurring ◽  
Triatoma Virus

scholarly journals Naturally occurring capsid protein variants L1 of human papillomavirus genotype 16 in Morocco

2017 ◽  
Vol 13 (08) ◽  
pp. 241-248 ◽  
Author(s):  
Aissam El-Aliani ◽  
◽  
My Abdelaziz El Alaoui ◽  
Imane Chaoui ◽  
My Mustapha Ennaji ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Capsid Protein ◽  
Naturally Occurring ◽  
Protein Variants

scholarly journals Comprehensive Assessment of the Antigenic Impact of Human Papillomavirus Lineage Variation on Recognition by Neutralizing Monoclonal Antibodies Raised against Lineage A Major Capsid Proteins of Vaccine-Related Genotypes

2020 ◽  
Vol 94 (24) ◽  
Author(s):  
Anna Godi ◽  
Dolcibella Boampong ◽  
Busayo Elegunde ◽  
Kavita Panwar ◽  
Maxime Fleury ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Human Papillomavirus ◽  
Capsid Protein ◽  
Capsid Proteins ◽  
Antigenic Determinants ◽  
Epithelial Cancers ◽  
Naturally Occurring ◽  
Hpv Genotypes ◽  
The Impact ◽  
Oncogenic Hpv

ABSTRACT Human papillomavirus (HPV) is the causative agent of cervical and other epithelial cancers. Naturally occurring variants of HPV have been classified into lineages and sublineages based on their whole-genome sequences, but little is known about the impact of this diversity on the structure and function of viral gene products. The HPV capsid is an icosahedral lattice comprising 72 pentamers of the major capsid protein (L1) and the associated minor capsid protein (L2). We investigated the potential impact of this genome variation on the capsid antigenicity of lineage and sublineage variants of seven vaccine-relevant, oncogenic HPV genotypes by using a large panel of monoclonal antibodies (MAbs) raised against the L1 proteins of lineage A antigens. Each genotype had at least one variant that displayed a ≥4-fold reduced neutralizing antibody sensitivity against at least one MAb, demonstrating that naturally occurring variation can affect one or more functional antigenic determinants on the HPV capsid. For HPV16, HPV18, HPV31, and HPV45, the overall impact was of a low magnitude. For HPV33 (sublineages A2 and A3 and lineages B and C), HPV52 (lineage D), and HPV58 (lineage C), however, variant residues in the indicated lineages and sublineages reduced their sensitivity to neutralization by all MAbs by up to 1,000-fold, suggesting the presence of key antigenic determinants on the surface of these capsids. These determinants were resolved further by site-directed mutagenesis. These data improve our understanding of the impact of naturally occurring variation on the antigenicity of the HPV capsid of vaccine-relevant oncogenic HPV genotypes. IMPORTANCE Human papillomavirus (HPV) is the causative agent of cervical and some other epithelial cancers. HPV vaccines generate functional (neutralizing) antibodies that target the virus particles (or capsids) of the most common HPV cancer-causing genotypes. Each genotype comprises variant forms that have arisen over millennia and which include changes within the capsid proteins. In this study, we explored the potential for these naturally occurring variant capsids to impact recognition by neutralizing monoclonal antibodies. All genotypes included at least one variant form that exhibited reduced recognition by at least one antibody, with some genotypes affected more than others. These data highlight the impact of naturally occurring variation on the structure of the HPV capsid proteins of vaccine-relevant oncogenic HPV genotypes.

scholarly journals Synthesis of Viral DNA and Late Capsid Protein L1 in Parabasal Spinous Cell Layers of Naturally Occurring Benign Warts Infected with Human Papillomavirus Type 1

Virology ◽  
2000 ◽  
Vol 268 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Kiyofumi Egawa ◽  
Angelika Iftner ◽  
John Doorbar ◽  
Yumi Honda ◽  
Thomas Iftner
Keyword(s):  
Human Papillomavirus ◽  
Capsid Protein ◽  
Viral Dna ◽  
Naturally Occurring ◽  
Cell Layers

scholarly journals Low-Level Secretion of Human Hepatitis B Virus Virions Caused by Two Independent, Naturally Occurring Mutations (P5T and L60V) in the Capsid Protein

2000 ◽  
Vol 74 (19) ◽  
pp. 9099-9105 ◽  
Author(s):  
Sophie Le Pogam ◽  
Thomas Ta-Tung Yuan ◽  
Gautam Kumar Sahu ◽  
Soma Chatterjee ◽  
Chiaho Shih
Keyword(s):  
Amino Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Capsid Protein ◽  
Core Protein ◽  
Wild Type Virus ◽  
Viral Dna ◽  
Naturally Occurring ◽  
Human Hepatitis ◽  
B Virus

ABSTRACT The functional significance of naturally occurring variants of human hepatitis B virus (HBV) remains largely unknown. Previously, we reported an immature secretion phenotype caused by a highly frequent mutation at amino acid 97 of the HBV core (capsid) protein (HBcAg). This phenotype is characterized by a nonselective and excessive secretion of virions containing an immature genome of single-stranded viral DNA. To extend our study of virion secretion to other naturally occurring variants, we have characterized mutations at HBcAg codons 5, 38, and 60 via site-directed mutagenesis. Although the phenotype of the mutation at codon 38 is nearly identical to that for the wild-type virus, our study reveals that a single mutation at codon 5 or 60 exhibits a new extracellular phenotype with significantly reduced virion secretion yet maintains normal intracellular viral DNA replication. A complementation study indicates that the mutant core protein alone is sufficient for the “low-secretion” phenotype. Furthermore, the low-secretion phenotype of the codon 5 mutant appears to be induced by the loss of a parental proline residue, rather than by the gain of a new amino acid. Our study underscores the core protein as another crucial determinant in virion secretion, in addition to the known envelope proteins. Our present results suggest that a very precise structure of both α-helical and nonhelical loop regions of the entire HBcAg molecule is important for virion secretion. The low-secretion variants may contribute to the phenomenon of gradually decreasing viremia in chronic carriers during the late phase of persistent infection.

Pathology of Bone Cells in Pigs with Experimental Turbinate Osteoporosis (Atrophic Rhinitis)

1971 ◽  
Vol 29 ◽  
pp. 304-305
Author(s):  
A. W. Fetter ◽  
C. C. Capen
Keyword(s):  
Mucous Membrane ◽  
Bone Cells ◽  
Atrophic Rhinitis ◽  
Infectious Agents ◽  
Metabolic Disturbances ◽  
Progressive Reduction ◽  
Naturally Occurring ◽  
Fundamental Cause ◽  
Osteocytic Osteolysis ◽  
Uncertain Etiology

Atrophic rhinitis in swine is a disease of uncertain etiology in which infectious agents, hereditary predisposition, and metabolic disturbances have been reported to be of primary etiologic importance. It shares many similarities, both clinically and pathologically, with ozena in man. The disease is characterized by deformity and reduction in volume of the nasal turbinates. The fundamental cause for the localized lesion of bone in the nasal turbinates has not been established. Reduced osteogenesis, increased resorption related to inflammation of the nasal mucous membrane, and excessive resorption due to osteocytic osteolysis stimulated by hyperparathyroidism have been suggested as possible pathogenetic mechanisms.The objectives of this investigation were to evaluate ultrastructurally bone cells in the nasal turbinates of pigs with experimentally induced atrophic rhinitis, and to compare these findings to those in control pigs of the same age and pigs with the naturally occurring disease, in order to define the fundamental lesion responsible for the progressive reduction in volume of the osseous core.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

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