Dept. of Biochemistry & Organic Chemistry
HCV enzymology
Hepatitis C Virus (HCV)
HCV is a flavivirus which causes a chronic inflammation in the liver. It is spread world wide and only treatment available to the more than 170 miljon infected people is only effective in some patients. Resistance is likely to arise against the new types of drugs being developed today, so there is an urgent need to understand the enzymology of the virus and identify novel mechanisms for drug action. The viral genome is translated into a single polyprotein that is proteolytically processed into functional proteins.
HCV NS2-3
The NS2-3 protein is a pro-form of the NS3 protease, but its autocatalytic processing is not catalysed by the NS3 active site, making it a unique activation mechanism. Few studies have been reported on the enzymology of this protein, although its structure and catalytic function has recently been published. We have had an interest in this enzyme, but the project is currently on hold.
HCV NS3
The bifunctional NS3 protein of HCV is an important drug target since it has both protease and helicase activities, both essential for viral replication. Our work has focused on the proteolytic activity if the enzyme. We have constructed a vector for expression of the full-length NS3, developed an effective purification strategy and methodology for characterization of the enzyme and its inhibition by different types of inhibitors. This has resulted in important structure-activity relationship that can be exploited for design of potent inhibitors. We have also studied how the helicase domain influences the protease activity of NS3 and the effect of substitutions predicted to arise under the selective pressure of protease inhibitors and thereby likely to be responsible for resistance.
HCV NS4A
The NS4A protein of HCV is removed from the viral polyprotein by the NS3 protease, and thereafter remains attached to the protease as a cofactor, giving structural stability to the enzyme. We are interested in the mechanism of this stabilization, and are therfore studing its interaction with the NS3 protein.
HCV NS5B
The viral NS5B protein is an RNA dependent RNA polymerase which also serves as an important target for anti-HCV drugs. Its role in the initiation of the replication of the virus remains to be established and we have therefore studied its interaction with viral RNA.