Physical Sciences Division
DOE Awards PNNL Contract for Single-Molecule Studies of Enzymes
Contact: Eric Ackerman
Pacific Northwest National Laboratory has been awarded a 3-year, $1.5-million contract by the Department of Energy (DOE) to develop a first-of-its-kind, multidisciplinary approach for studying the molecular mechanisms of enzymes. Enzymes—the protein nanomachines of cells—have potential energy applications such as hydrogen production, fuel cell development, and high-efficiency lighting. However, to develop these applications, gaps in the fundamental understanding of enzymatic processes must be filled. The work is funded by DOE's Energy Biosciences program within the Office of Basic Energy Sciences, and according to Bruce Garrett, Director, PNNL's Chemical Sciences Division, "This success is particularly
noteworthy since it is PNNL's first project funded by DOE's Energy Biosciences in recent years."
Cyclic voltammetry coupled single-molecule spectroscopy being developed by PNNL is a 3-electrode platform to oxidize and reduce enzymes. The confined enzyme in nanomaterials will be spin-coated on a transparent indium tin oxide (ITO) working electrode surrounded by a hydrophobic tape. The working buffer will be deposited on the confined enzyme area to form a miniature electrochemical cell.
Redox enzymes, which catalyze electron transfer reaction cycles of reduction and oxidation (redox), are especially important because electron transfer reactions are essential to all life forms. Gaining a fundamental understanding of enzymes and their processes has been a long-standing scientific challenge because enzymes are typically unstable outside of their cellular environment, making them hard to study.
The PNNL researchers' novel approach is to couple cyclic voltammetry, an electrochemical method, with single-molecule spectroscopy to advance chemical imaging of enzymes that are of strategic significance in the research areas of energy biosciences, chemical energy, and chemical engineering. They will study the dynamics of oxidized and reduced enzymes confined in nano-environments. Selective mutation and attachment of fluorescent centers will enable accurate assessment of the nano-environment and degree of confinement of the individual redox enzyme under study by monitoring fluorescent changes during cyclic voltammetry.
Principal investigator is Eric Ackerman, and co-principal investigators are Chenghong Lei, Dehong Hu, and Chuck Windisch.