Hepatitis B Virus Ribonuclease H: Mechanisms of Catalysis and Inhibition
Abstract
Hepatitis B Virus (HBV) causes chronic hepatitis, cirrhosis, liver failure, and liver cancer, but current drugs cannot fully control viral replication or stop disease progression. HBV replicates by reverse transcription. The viral ribonuclease H (RNaseH) removes the viral RNA after it has been copied into the first DNA strand so that the second strand can be made. Lack of RNaseH activity causes viral DNA replication to fail. Despite being essential for viral replication and an obvious drug target, the HBV RNaseH is poorly characterized. This project will generate the first in-depth biochemical data about function and inhibition of the RNaseH. Specifically, it will define the interaction between the RNaseH and its Mg++ ion cofactor, assess binding between the RNaseH and its substrate, define the mechanism of inhibition induced by multiple classes of RNaseH inhibitors, and provide the first structure-function analysis of the enzyme. The status as we approach the end of the second year of this project is that we have defined: i) The affinity of the two Mg++ for the RNaseH to be approximately 0.5 micrometerM; ii) Found that Mg++ concentration has no effect on substrate binding; iii) Found that inhibitor binding to the RNaseH is strongly dependent upon Mg++ and that inhibition of the enzyme is primarily mixed-mode with some effects on catalysis; iv) Continue to improve purification conditions for the RNaseH; v) Have g
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2020
- Accession Number
- AD1115241
Entities
People
- John E Tavis
Organizations
- Saint Louis University