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Order Nidovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Figure 26.1 presents schematic cartoons of the order representatives, which are intended to show the previously mentioned diversity of viral architecture. As reviewed by de Groot et al. (2012), the members of the Coronaviridae family are roughly spherical enveloped particles, 120–160 nm in diameter, with a characteristic fringe of 15–20 nm petal-shaped surface projections termed peplomers. In the previously mentioned famous Betacoronavirus genus, a second, inner fringe of 5–7 nm surface projections is also seen. The CoV particles as studied by electron cryotomography are homogeneous in size and distinctively spherical with outer diameter 85 ± 5 nm of envelope. The envelope exhibits an unusual thickness (7.8 ± 0.7 nm), almost twice that of a typical biological membrane. The nucleocapsid is helical and tightly folded to form a compact structure that tends to closely follow the envelope. The arterivirus virions are significantly smaller than those of the other nidoviruses, spherical or egg-shaped and with a seemingly isometric core that contains the genome. The complete particles and nucleocapsids, as measured by electron cryomicroscopy, average 54 nm and 39 nm in diameter, respectively. No spikes are obvious on the arterivirus surface.
Classification of Hemorrhagic Fevers
Published in James H. S. Gear, CRC Handbook of Viral and Rickettsial Hemorrhagic Fevers, 2019
The name Togavirus refers to the envelope and is derived from the Latin ‘toga’ — a Roman mantle or cloak. The family Togaviridae now comprises four genera, namely, Alphavirus with 26 species, Rubivirus (one species), Pestivirus (three species), and Arterivirus (one species). The virions are spherical, 40 to 70 nm in diameter, and mature by budding of nucleocapsids through plasma membranes. The virus envelope carries surface projections associated with two proteins, El and E2, that are usually glycosylated. El is the functional hemagglutinin for Alphaviruses. The envelope encloses the spherical nucleocapsid (diameter 28 to 35 nm) with icosohedral symmetry. The genome is a single molecule of single-stranded RNA with a molecular weight of about 4 × 106. The gene sequence of the Alphavirus genus has been determined.
Zinc pyrithione is a potent inhibitor of PLPro and cathepsin L enzymes with ex vivo inhibition of SARS-CoV-2 entry and replication
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Jerneja Kladnik, Ana Dolinar, Jakob Kljun, David Perea, Judith Grau-Expósito, Meritxell Genescà, Marko Novinec, Maria J. Buzon, Iztok Turel
Pyrithione a is a known ionophore with the ability to bind zinc ions, increase their intracellular concentration64 and as such has recognised antiviral activity against coronavirus (SARS-CoV), arterivirus, coxsackievirus, mengovirus, picornavirus, and rhinovirus65. A decade ago, te Velthuis et al. demonstrated that the combination of Zn2+ ions and pyrithione a effectively inhibited the replication of SARS-CoV via Zn2+ suppression of RdRp25. In addition, zinc pyrithione 1a is an established antimicrobial agent used in commercial shampoos for dandruff33 treatment and exerts antifungal activity by damaging iron-sulphur clusters32–34. Recently, Maio et al. have suggested that Fe–S clusters act as cofactors of the SARS-CoV-2 RdRp enzyme and therefore represent another potential target to combat COVID-1935. Therefore, pyrithione a and its zinc complex 1a have attracted much attention to combat SARS-CoV-2 during the COVID-19 pandemic because of the aforementioned antimicrobial effects. However, no systematic study on zinc-pyrithione complexes was reported so far.
Research progress in the development of porcine reproductive and respiratory syndrome virus as a viral vector for foreign gene expression and delivery
Published in Expert Review of Vaccines, 2020
Guo Dai, Mei Huang, To Sing Fung, Ding Xiang Liu
PRRSV belongs to the genus Porarterivirus, together with the other four genera, Equarterivirus, Simarterivirus, Diparterivirus, Nesarterivirus, placing within the family Arteriviridae of the order Nidovirales [4]. This family includes other members, such as lactate dehydrogenase-elevating virus of mice (LDV), simian hemorrhagic fever virus (SHFV), equine arterivirus (EAV) and the recently described wobbly possum disease virus (WPDV) [1,5,6]. According to the latest classification system, the traditional two genotypes of PRRSV, European (Type 1) and North American (Type 2), can be reclassified into two different species, betaarterivirus suid 1 species for PRRSV 1 and betaarterivirus suid 2 for PRRSV 2, sharing less than 70% sequence identity [7].