Our lab is interested in engineering molecular therapeutics using chemical and biological tools. Under this broad umbrella, we focus on three areas of research to combat infectious diseases and cancer. The first area is to understand how nature produces complex small-molecule natural products. These structurally sophisticated compounds have been used as drugs or leads for drugs to treat a variety of human diseases. Our goals are to reveal the enzymatic basis for the biosynthesis of these compounds, and use the knowledge to assemble synthetic biological pathways for production of new compounds with improved or novel activities. The second area is biocatalysis, in which we use protein and metabolic engineering efforts to construct new routes for the production of important therapeutics. This area is represented by our recent work on the development of an efficient biocatalytic process of for the synthesis of simvastatin, which received the US EPA Green Chemistry Prize in 2012. The third area is using nanoparticles for the delivery of protein-based therapeutics to the intracellular compartments of mammalian cells. We have developed a new, nanogel-based approach that can efficiently delivery different proteins to a variety of human cell lines in functional forms. Our approach overcomes the difficulties involved in administering cytosolic and nuclear proteins as therapeutics. In this talk, I will talk about our recent work in all of these areas.