Enzymes are proteins which function as biological catalysts, playing an important role in nearly all processes taking place in living organisms. As a result, studies of these biological molecules and the reactions they catalyse is of interest, especially when considering the development of novel therapeutics against diseases such as cancer. A number of drugs are already available which inhibit enzyme activity. Development of new inhibitors requires an understanding of the way an enzyme binds and then process the natural substrate.

In this webinar we will consider how Isothermal titration Calorimetry (ITC) can be applied to understand enzyme inhibition and activation. ITC was originally designed for studying host/guest binding interactions but is gaining popularity as general enzyme assay. To characterize enzyme activity, ITC measures the heat released or absorbed by catalysis in real time, following the rapid mixing of enzyme and substrate solutions. Since most chemical reactions are either exothermic or endothermic, ITC can be applied to virtually any enzyme/substrate pair, without the need to design customized reporter molecules, to couple the reaction to additional enzymes, or to perform any post-reaction separation. In addition, ITC experiments can be performed under dilute, physiological solution conditions, even with opaque samples and require far less enzyme than traditional ITC binding experiments.

Basic concepts in ITC enzyme assays will be introduced together with recent developments from our lab, followed by some case studies that illustrate the capabilities of the technique. The results we present help illustrate the broad applicability of ITC to better understanding enzyme inhibition.