Marketed drugs have been developed for representatives of all six classes of enzymes, and comprise essential therapies for the treatment of cancers, HIV/AIDS, hypercholesterolemia, and bacterial infections. The availability of known point mutations that are causative of human cancers , as well as the full genomic descriptions of many pathogens, such as parasitic protozoa and infectious bacteria, provides an emerging means to identify new or known enzymes that would constitute potential drug targets. Likewise, the availability of crystal structures of many of these enzymes or their analogues, provides a means to rationally design new inhibitors of enzyme drug targets via the use of molecular modelling and a full understanding of the chemical mechanism of the target enzymes, as an important adjuvant to inhibitor discovery via high-throughput screening.
Our laboratory will initially focus on the detailed study of the mechanisms of cysteine proteases such as cathepsin C, the isocitrate lyase of Mycobacterium tuberculosis, and human ATP-citrate lyase, by the use of pre-steady-state and steady-state kinetics, as well as by use of existing crystal structures of these enzymes, to inform the design of both covalent and other mechanism-based modes for the inactivation of these enzymes. We will design and synthesize candidate inhibitors, and test them against these and other enzyme targets, and determine their suitability as potential drug candidates.