Surface Plasmon Resonance as a Tool to Select Potent Drug Candidates for Hepatitis C Virus NS5B Polymerase

: Surface plasmon resonance (SPR)-based optical biosensors have been widely used to study biomolecular interactions, and applied to many areas of drug discovery including target identification, fragment screening, lead compound selection, early ADME (absorption, distribution, metabolism and excretion), and quality control. These biosensors allow the following of a biomolecular interaction in real time to monitor kinetics and determine affinity. In this chapter, we describe an SPR-based assay to measure the interaction between hepatitis C virus NS5B polymerase (wild type and/or mutants) and a small-molecule inhibitor. Viral polymerase proteins are captured on a Ni(2+)-nitrilotriacetic acid sensor surface while the small--molecule inhibitors are passed over the surface. In this way kinetics and affinity of the enzyme-inhibitor interactions can be measured, making it possible to select potent and promising lead candidates.