Design and Selection of Metalloenzymes and their Applications as Biocatalysts in Alternative Energies and as Biosensors in Environmental Monitoring, Medical Diagnostics and Imaging

Seminar | February 9 | 4-5 p.m. | 120 Latimer Hall

 Yi Lu, Department of Chemistry, University of Illinois at Urbana-Champaign

 College of Chemistry

Metalloenzymes play important roles in numerous biological processes. Designing metalloenzymes is an
ultimate test of our knowledge about metalloenzymes and can result in new biocatalysts for practical
applications such as in alternatives energies. We have been focusing ways to design heteronuclear
metalloenzymes involved in multiple electron redox processes, such as heme-copper oxidase, heme-non- hem
iron nitric oxide reductase and heme-[4Fe4S] cluster sulfite reductase. In the process, we demonstrate, while
reproducing the primary coordination sphere may be good enough to make structural models of
metalloproteins, careful design of the non-covalent secondary coordination sphere interactions, such as
hydrophobicity and hydrogen bonding interactions, including those involving waters, are required to create
functional metalloenzymes with high activity and turnover numbers comparable to those of native enzymes.

While metalloproteins have been the major focus of metalloenzyme research for decades, metallo-
DNAzymes, DNA molecules containing metal ions at the active site and displaying enzymatic activities,
have emerged as a new class of metalloenzymes. We have been using in vitro selection to obtain from a large
DNA library DNAzymes that are specific for metal ions and use spectroscopic methods to elucidate how and
why DNAzymes can recognize metal ions selectively. We have also converted these DNAzymes into highly
sensitive and selective sensors for metal ions, including those metal ions that are difficult to design using
other methods, and demonstrated their applications in environmental monitoring, food safety, and medical
diagnostics. The use of these metal-DNAzymes for imaging metal ions in living cells and animals has also
been demonstrated and these metal-selective imaging agents are providing deeper insights into beneficial and
deleterious effects of metal ions in biological systems.

 Light refreshments will be served at 3:50 at The Coffee Lab

 seminarcoordinator-cchem@berkeley.edu, 510-643-0572