Search results for "Structural protein"
showing 10 items of 116 documents
Role of nitric oxide during rotavirus infection.
2006
The pathophysiological mechanisms behind rotavirus-induced diarrhoea still remain incomplete. Current views suggest that the non-structural protein 4 (NSP4) of rotavirus and the enteric nervous system (ENS) participate in water secretion and diarrhoea. In the present work the role of nitric oxide (NO) in rotavirus infection and disease has been studied in vitro, mice and humans. Incubation of human intestinal epithelial cells (HT-29) with purified NSP4 but not with infectious virus produced NO2/NO3 accumulation in the incubation media. The NSP4-induced release of NO metabolites occurred within the first minutes after the addition of the toxin. Mice infected with murine rotavirus (strain EDI…
Targeting SARS-CoV-2 Main Protease for Treatment of COVID-19: Covalent Inhibitors Structure-Activity Relationship Insights and Evolution Perspectives
2022
The viral main protease is one of the most attractive targets among all key enzymes involved in the SARS-CoV-2 life cycle. Covalent inhibition of the cysteine145 of SARS-CoV-2 MPRO with selective antiviral drugs will arrest the replication process of the virus without affecting human catalytic pathways. In this Perspective, we analyzed the in silico, in vitro, and in vivo data of the most representative examples of covalent SARS-CoV-2 MPRO inhibitors reported in the literature to date. In particular, the studied molecules were classified into eight different categories according to their reactive electrophilic warheads, highlighting the differences between their reversible/irreversible mech…
Oral immunization with HCV-NS3-transformed Salmonella: induction of HCV-specific CTL in a transgenic mouse model.
2001
Abstract Background & Aims: The ability to induce cytotoxic T cells is considered an important feature of a candidate hepatitis C virus (HCV) vaccine. We used an oral immunization strategy with attenuated HCV-NS3–transformed Salmonella typhimurium to deliver DNA directly to the gut-associated lymphoid tissue. Methods: HLA-A2.1 transgenic mice were immunized once with transformed attenuated Salmonella . HCV-specific CD8 + T cells were analyzed in vitro as well as in vivo by challenge of mice with recombinant HCV-NS3 vaccinia virus. Results: Salmonella (10 8 colony-forming units; 20 μg plasmid DNA) induced cytotoxic and IFN-γ–producing CD8 + T cells specific for the immunodominant epitope NS3…
Genomic characterization of a novel group A lamb rotavirus isolated in Zaragoza, Spain.
2008
An ovine rotavirus (OVR) strain, 762, was isolated from a 30-day-old lamb affected with severe gastroenteritis, in Zaragoza, Spain, and the VP4, VP7, VP6, NSP4, and NSP5/NSP6 genes were subsequently characterized molecularly. Strain OVR762 was classified as a P[14] rotavirus, as the VP4 and VP8* trypsin-cleavage product of the VP4 protein revealed the highest amino acid (aa) identity (94% and 97%, respectively) with that of the P11[14] human rotavirus (HRV) strain PA169, isolated in Italy. Analysis of the VP7 gene product revealed that OVR762 possessed G8 serotype specificity, a type common in ruminants, with the highest degree of aa identity (95–98%) shared with serotype G8 HRV, bovine rot…
Phylodynamic Analysis and Implication of HCV Genotype 4 Variability on Antiviral Drug Response and T-Cell Recognition.
2020
Therapies for HCV care could change the prevalence and the geographic distribution of genotypes due to differences in Sustained Virologic Response (SVR). In this scenario, uncommon genotypes/subtypes, such as genotype 4, could spread from high-risk groups, replacing genotypes eradicated by antiviral drugs. Genotype eradication is also strongly influenced by the CD8+ T cell response. In this study, the genetic variability in HCV genotype 4 strains obtained from a cohort of 67 patients naï
Probing protein interactions in the membrane-containing virus PRD1.
2015
PRD1 is a Gram-negative bacteria infecting complex tailless icosahedral virus with an inner membrane. This type virus of the family Tectiviridae contains at least 18 structural protein species, of which several are membrane associated. Vertices of the PRD1 virion consist of complexes recognizing the host cell, except for one special vertex through which the genome is packaged. Despite extensive knowledge of the overall structure of the PRD1 virion and several individual proteins at the atomic level, the locations and interactions of various integral membrane proteins and membrane-associated proteins still remain a mystery. Here, we demonstrated that blue native PAGE can be used to probe pro…
The Putative Metal Coordination Motif in the Endonuclease Domain of Human Parvovirus B19 NS1 Is Critical for NS1 Induced S Phase Arrest and DNA Damage
2011
The non-structural proteins (NS) of the parvovirus family are highly conserved multi-functional molecules that have been extensively characterized and shown to be integral to viral replication. Along with NTP-dependent helicase activity, these proteins carry within their sequences domains that allow them to bind DNA and act as nucleases in order to resolve the concatameric intermediates developed during viral replication. The parvovirus B19 NS1 protein contains sequence domains highly similar to those previously implicated in the above-described functions of NS proteins from adeno-associated virus (AAV), minute virus of mice (MVM) and other non-human parvoviruses. Previous studies have show…
Non-structural proteins P17 and P33 are involved in the assembly of the internal membrane-containing virus PRD1.
2015
AbstractBacteriophage PRD1, which has been studied intensively at the structural and functional levels, still has some gene products with unknown functions and certain aspects of the PRD1 assembly process have remained unsolved. In this study, we demonstrate that the phage-encoded non-structural proteins P17 and P33, either individually or together, complement the defect in a temperature-sensitive GroES mutant of Escherichia coli for host growth and PRD1 propagation. Confocal microscopy of fluorescent fusion proteins revealed co-localisation between P33 and P17 as well as between P33 and the host chaperonin GroEL. A fluorescence recovery after photobleaching assay demonstrated that the diff…
Biochemical and Kinetic Analyses of NS5B RNA-Dependent RNA Polymerase of the Hepatitis C Virus
1998
The biochemical properties of the RNA-dependent RNA polymerase (RdRp) of the hepatitis C virus were analyzed. A hexahistidine affinity-tagged NS5B fusion protein was expressed with recombinant baculoviruses in insect cells and purified to near homogeneity. Enzymatic activity of the purified protein was inhibited by KCl or high concentrations of NaCl and was absolutely dependent on Mg2+, which could be replaced by Mn2+. NS5B was found to be processive and able to copy long heteropolymeric templates with an elongation rate of 150-200 nucleotides/min at 22 degreesC. Kinetic constants were determined for all four nucleoside triphosphates and different templates. In case of a heteropolymeric RNA…
Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins.
2019
A virus needs the host cell in order to replicate and produce new progeny viruses. For this, the virus takes over the host cell and modifies it to become a factory for viral proteins. Irrespective of the specific virus family, these proteins can be divided into structural and nonstructural proteins. Structural proteins are the building blocks for the new progeny virions, whereas the nonstructural proteins orchestrate the takeover of the host cell and its functions. Here, we have shown a mechanism that viruses exploit in order to regulate the host cell. We show that viral protein synthesis induces vimentin cages, which promote production of specific viral proteins that eventually control apo…