Research

Our Research

The Leung Research Group focuses on the enzymology that involves in protein function modulation. We apply a range of biophysical, chemical biology and structural biology techniques to enable our discoveries.

Metabolic regulation of protein functions

The ability to maintain homeostasis is critical to all forms of life. One mechanism through which this is achieved is the fine-tuning of cellular enzyme activities. In our group, we study how posttranslational modifications and metabolites affect the structure, activity and function of proteins and enzymes. These allow us to understand how different biochemical pathways signal and interact with one another to maintain stability in response to stress conditions. We are currently studying the enzymes that are involved in the regulation of carbon metabolism in Mycobacterium tuberculosis to understand how the pathogen survives inside the infected host with limited nutrients. Another system that we are studying is the plant ethylene-forming enzyme. We are presently investigating the mechanisms and structures of the different enzyme isoforms with a view to developing a detailed understanding of their roles in plant growth and development.

Enzyme technology for bioremediation

Enzymes are highly efficient catalysts that speed up chemical transformations under mild conditions. In our group, we study how we could harness the incredible catalytic prowess of enzymes as green biocatalysts to degrade environmental pollutants. We are especially interested in laccases, a class of multi-copper oxidase enzymes that catalyze one-electron oxidation of aromatic amine and phenolic substrates. Currently, we are studying how laccases mediate the degradation of organic pollutants at a molecular level to understand their mechanisms of catalysis. We also characterize the degradation products under different reaction conditions to investigate plausible degradation pathways.

Inhibitor discovery strategies and applications

The ability to modulate the activity of enzymes using natural or synthetic compounds has enormous potential in areas such as medicine. An important step in the early stages of inhibitor development is the identification and characterization of ligands that bind to the target. Our laboratory specializes in the application of biophysical techniques, especially NMR spectroscopy, for ligand screening and to study protein-ligand interactions and enzyme inhibition. A current interest is the development of inhibitors for lipid A phosphoethanolamine transferases. Such compounds have potential to be used as adjuvants to reverse bacterial resistance to polymyxins, a class of last-line antibiotics to treat multidrug-resistant infections.