Search results for "Dengue virus"

Flavonoids as noncompetitive inhibitors of Dengue virus NS2B-NS3 protease: Inhibition kinetics and docking studies

2014

NS2B-NS3 is a serine protease of the Dengue virus considered a key target in the search for new antiviral drugs. In this study flavonoids were found to be inhibitors of NS2B-NS3 proteases of the Dengue virus serotypes 2 and 3 with IC50 values ranging from 15 to 44 μM. Agathisflavone (1) and myricetin (4) turned out to be noncompetitive inhibitors of dengue virus serotype 2 NS2B-NS3 protease with Ki values of 11 and 4.7 μM, respectively. Docking studies propose a binding mode of the flavonoids in a specific allosteric binding site of the enzyme. Analysis of biomolecular interactions of quercetin (5) with NT647-NHS-labeled Dengue virus serotype 3 NS2B-NS3 protease by microscale thermophoresis…

An epigenetic ‘extreme makeover’: the methylation of flaviviral RNA (and beyond)

2020

Beyond their high clinical relevance worldwide, flaviviruses (comprising dengue and Zika viruses) are of particular interest to understand the spatiotemporal control of RNA metabolism. Indeed, their positive single-stranded viral RNA genome (vRNA) undergoes in the cytoplasm replication, translation and encapsidation, three steps of the flavivirus life cycle that are coordinated through a fine-tuned equilibrium. Over the last years, RNA methylation has emerged as a powerful mechanism to regulate messenger RNA metabolism at the posttranscriptional level. Not surprisingly, flaviviruses exploit RNA epigenetic strategies to control crucial steps of their replication cycle as well as to evade sen…

Proline-Based Allosteric Inhibitors of Zika and Dengue Virus NS2B/NS3 Proteases

2019

The NS2B/NS3 serine proteases of the Zika and Dengue flaviviruses are attractive targets for the development of antiviral drugs. We report the synthesis and evaluation of a new, proline-based compound class that displays allosteric inhibition of both proteases. The structural features relevant for protease binding and inhibition were determined to establish them as new lead compounds for flaviviral inhibitors. Based on our structure-activity relationship studies, the molecules were further optimized, leading to inhibitors with submicromolar IC50 values and improved lipophilic ligand efficiency. The allosteric binding site in the proteases was probed using mutagenesis and covalent modificati…

Anti-herpetic and anti-dengue activity of abietane ferruginol analogues synthesized from (+)-dehydroabietylamine

2015

The abietane-type diterpenoid (+)-ferruginol (1), a bioactive compound isolated from several plants, has attracted much attention as consequence of its pharmacological properties, which includes antibacterial, antifungal, antimicrobial, cardioprotective, anti-oxidative, anti-plasmodial, leishmanicidal, anti-ulcerogenic, anti-inflammatory and antitumor actions. In this study, we report on the antiviral evaluation of ferruginol (1) and several analogues synthesized from commercial (+)-dehydroabietylamine. Thus, the activity against Human Herpesvirus type 1, Human Herpesvirus type 2 and Dengue Virus type 2, was studied. Two ferruginol analogues showed high antiviral selectivity index and reduc…

Joint Estimation of Relative Risk for Dengue and Zika Infections, Colombia, 2015–2016

2019

We jointly estimated relative risk for dengue and Zika virus disease (Zika) in Colombia, establishing the spatial association between them at the department and city levels for October 2015–December 2016. Cases of dengue and Zika were allocated to the 87 municipalities of 1 department and the 293 census sections of 1 city in Colombia. We fitted 8 hierarchical Bayesian Poisson joint models of relative risk for dengue and Zika, including area- and disease-specific random effects accounting for several spatial patterns of disease risk (clustered or uncorrelated heterogeneity) within and between both diseases. Most of the dengue and Zika high-risk municipalities varied in their risk distributio…

Hepatīta B kora antigēna veidoto vīrusveidīgo daļiņu modificēšana vakcīnu prototipa izstrādei

2017

DENV vakcīnu izveide balstās galvenokārt, izmantojot dzīvus novājinātus vīrusus. 2015. gadā tika reģistrēta pirmā tetravalenta novājināta denges vīrusa vakcīna. Kā drošāks vakcīnas veids ir subvienību vakcīnas. Daudzsološākais DENV antigēns subvienību vakcīnas izveidē ir apvalka proteīna III domēns. Lai palielinātu antigēna subvienības imunogenitāti, tiek izmantotas vīrusveidīgās daļiņas (VLP) kā svešu antigēnu nesēji. Tā kā VLP ir pašnereplicējošas, tās tiek uzskatītas par drošākiem kandidātiem vakcīnu izveidē, salīdzinot ar dzīviem novājinātiem vīrusiem. Maģistra darba mērķis bija iegūt 2. serotipa denges vīrusa apvalka III domēnu (DV2-III) prezentējošas mutantās HBc VLP. Pētījumā tika pā…

Vascular Leakage in Severe Dengue Virus Infections: A Potential Role for the Nonstructural Viral Protein NS1 and Complement

2006

Background Vascular leakage and shock are the major causes of death in patients with dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Thirty years ago, complement activation was proposed to be a key underlying event, but the cause of complement activation has remained unknown. Methods The major nonstructural dengue virus (DV) protein NS1 was tested for its capacity to activate human complement in its membrane-associated and soluble forms. Plasma samples from 163 patients with DV infection and from 19 patients with other febrile illnesses were prospectively analyzed for viral load and for levels of NS1 and complement-activation products. Blood and pleural fluids from 9 patient…

SAR of novel benzothiazoles targeting an allosteric pocket of DENV and ZIKV NS2B/NS3 proteases

2021

In recent years, dengue virus (DENV) and Zika virus (ZIKV), both mosquito-borne members of the Flaviviridae family, have emerged as intercontinental health issues since their vectors have spread from their tropical origins to temperate climate zones due to climate change and increasing globalization. DENV and ZIKV are positive-sense, single-stranded RNA viruses, whose genomes consist of three structural (capsid, membrane precursor, envelope) and seven non-structural (NS) proteins, all of which are initially expressed as a single precursor polyprotein. For virus maturation, the polyprotein processing is accomplished by host proteases and the viral NS2B/NS3 protease complex, whose inhibitors …

Biochemistry and medicinal chemistry of the dengue virus protease.

2014

Conformational Dynamics of the Dengue Virus Protease Revealed by Fluorescence Correlation and Single-Molecule FRET Studies.

2021

The dengue virus protease (DENV-PR) represents an attractive target for counteracting DENV infections. It is generally assumed that DENV-PR can exist in an open and a closed conformation and that active site directed ligands stabilize the closed state. While crystal structures of both the open and the closed conformation were successfully resolved, information about the prevalence of these conformations in solution remains elusive. Herein, we address the question of whether there is an equilibrium between different conformations in solution which can be influenced by addition of a competitive inhibitor. To this end, DENV-PR was statistically labeled by two dye molecules constituting a FRET …