Currently, hepatitis C virus (HCV) infection is considered a serious health-care problem all over the world. A good number of direct-acting antivirals (DAAs) against HCV infection are in clinical progress including NS3-4A protease inhibitors, RNA-dependent RNA polymerase inhibitors, and NS5A inhibitors as well as host targeted inhibitors. Two NS3-4A protease inhibitors (telaprevir and boceprevi...

Persistent infections of hepatitis C virus (HCV) are known to be a major risk factor for causing hepatocellular carcinomas. Nonstructural protein 3 (NS3) of HCV has serine protease and RNA helicase domains, and is essential for the viral replication. Further, NS3 is also considered to be involved in the development of HCV-induced hepatocellular carcinomas. In this report, we focus on the functi...

This study examines the specificity and mechanism of action of a recently reported hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase-protease inhibitor (HPI), and the interaction of HPI with the NS3 protease inhibitors telaprevir, boceprevir, danoprevir, and grazoprevir. HPI most effectively reduced cellular levels of subgenomic genotype 4a replicons, followed by genotypes 3a and 1...

The dengue virus (DENV) genome encodes 10 different genes including the NS3 gene, which has a protease and helicase domain used in virus replication. This domain is a potential target for antiviral agents against dengue. Due to a high mutation rate, DENV is classified into four major serotypes (DENV1-DENV4). This study was designed to perform conservancy analysis of all four serotypes by drawin...

Core protein of Flaviviridae is regarded as essential factor for nucleocapsid formation. Yet, core protein is not encoded by all isolates (GBV- A and GBV- C). Pestiviruses are a genus within the family Flaviviridae that affect cloven-hoofed animals, causing economically important diseases like classical swine fever (CSF) and bovine viral diarrhea (BVD). Recent findings describe the ability of N...

Dengue fever and dengue hemorrhagic fever/dengue shock syndrome are highly infectious diseases caused by dengue virus (DV). DV non-structural protein 3 (NS3) is known to possess ATPase, helicase, and protease activity that is a constitutive part of the replication complex of DV. In this study, we discuss the cloning, expression, and purification of the DV-2 NS3 protein to immunize mice by intra...

Hepatitis C virus (HCV) helicase, non-structural protein 3 (NS3), is proposed to aid in HCV genome replication and is considered a target for inhibition of HCV. In order to investigate the substrate requirements for nucleic acid unwinding by NS3, substrates were prepared by annealing a 30mer oligonucleotide to a 15mer. The resulting 15 bp duplex contained a single-stranded DNA overhang of 15 nt...

The NS3 ATPase/helicase was isolated and characterized from three different infectious clones of hepatitis C virus (HCV). One helicase was from a genotype that normally responds to therapy (Hel-2a), and the other two were from more resistant genotypes, 1a (Hel-1a) and 1b (Hel-1b). Although the differences among these helicases are generally minor, all three enzymes have distinct properties. Hel...

Pestivirus nonstructural protein 3 (NS3) is a multifunctional with protease and helicase activities that are essential for virus replication. In this study, we used combination of biochemical genetic approaches to investigate the relationship between positively charged patch on module NS3 function. The surface composed four basic residues, R50, K74 K94 in domain H24 structurally integrated cofa...