The HCV non-nucleoside inhibitor Tegobuvir utilizes a novel mechanism of action to inhibit NS5B polymerase function

Autor: Maisoun Sulfab, Weidong Zhong, Vivian Randall W, Steven S. Bondy, Wanchi Fung, Hengli Tang, Uli Schmitz, Christy M. Hebner, Johan Neyts, Michelle Nash, Trenkle James D, Magdeleine Hung, Xiaohong Liu, John O. Link, Roman Sakowicz, Yang Tian, Katherine M. Brendza, Kyla Bjornson, James G. Taylor, Bin Han
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Gastroenterology and hepatology
viruses
Hepacivirus
Viral Nonstructural Proteins
Biochemistry
Mass Spectrometry
law.invention
chemistry.chemical_compound
law
Drug Discovery
Polymerase
chemistry.chemical_classification
Multidisciplinary
biology
Reverse Transcriptase Polymerase Chain Reaction
virus diseases
Transfection
Antivirals
Hepatitis C
Enzymes
Pyridazines
Infectious hepatitis
Recombinant DNA
Medicine
medicine.symptom
Research Article
Drugs and Devices
Drug Research and Development
Immunoprecipitation
Science
Blotting
Western
Antiviral Agents
Microbiology
Cell Line
Virology
medicine
Humans
Biology
NS5B
Liver diseases
DNA Primers
Enzyme Kinetics
Base Sequence
biochemical phenomena
metabolism
and nutrition
Molecular biology
Viral Replication
digestive system diseases
Enzyme
Mechanism of action
chemistry
Purines
biology.protein
Heterologous expression
Zdroj: PLoS ONE, Vol 7, Iss 6, p e39163 (2012)
PLoS ONE
ISSN: 1932-6203
Popis: Tegobuvir (TGV) is a novel non-nucleoside inhibitor (NNI) of HCV RNA replication with demonstrated antiviral activity in patients with genotype 1 chronic HCV infection. The mechanism of action of TGV has not been clearly defined despite the identification of resistance mutations mapping to the NS5B polymerase region. TGV does not inhibit NS5B enzymatic activity in biochemical assays in vitro, suggesting a more complex antiviral mechanism with cellular components. Here, we demonstrate that TGV exerts anti-HCV activity utilizing a unique chemical activation and subsequent direct interaction with the NS5B protein. Treatment of HCV subgenomic replicon cells with TGV results in a modified form of NS5B with a distinctly altered mobility on a SDS-PAGE gel. Further analysis reveals that the aberrantly migrating NS5B species contains the inhibitor molecule. Formation of this complex does not require the presence of any other HCV proteins. The intensity of the aberrantly migrating NS5B species is strongly dependent on cellular glutathione levels as well as CYP 1A activity. Furthermore analysis of NS5B protein purified from a heterologous expression system treated with TGV by mass spectrometry suggests that TGV undergoes a CYP- mediated intracellular activation step and the resulting metabolite, after forming a glutathione conjugate, directly and specifically interacts with NS5B. Taken together, these data demonstrate that upon metabolic activation TGV is a specific, covalent inhibitor of the HCV NS5B polymerase and is mechanistically distinct from other classes of the non-nucleoside inhibitors (NNI) of the viral polymerase.
Databáze: OpenAIRE
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