11/17/2008
Microbe to Metal Oxide Surface Binding Mechanism Provides Insight for Advancing Enzyme-Based Fuel Cell Research
Summary
In an effort to advance the development of enzyme-based fuel cells, a team of geologists, biologists, and computer scientists from the Pacific Northwest National Laboratory (PNNL), The Ohio State University, and Virginia Tech screened 3 billion different polypeptides to investigate their ability to bind to hematite, a metal oxide that could serve as an electrode surface. The team discovered that a segment of polypeptides that is just 9 amino acids long is the motif that binds these polypeptides to the iron oxide hematite. Molecular dynamics simulations of the binding interactions revealed that the polypeptide flexibility is limited in a way that promotes the formation of hydrogen bonding between the polypeptide and the mineral surface. Because enzyme-based fuel cells could be more efficient at transferring electrons to an electrode surface than microbial fuel cells, it is important to understand the fundamental chemical and physical mechanisms of polypeptide binding to electrode surfaces. These results not only provide important insights into advancing enzyme-based fuel cell research, but they also have implications for understanding the interactions of microorganisms with iron oxides found in soils and the subsurface. This research was funded by the DOE Office of Basic Energy Sciences Geosciences Research Program, the DOE Office of Advanced Scientific Computing Research, and the National Science Foundation, and conducted at DOE’s Environmental Molecular Sciences Laboratory user facility located in Richland, Washington.
References
Lower BH, RD Lins, ZW Oestreicher, TP Straatsma, MF Hochella, Jr., L Shi, and SK Lower. 2008. “In Vitro Evolution of a Peptide with a Hematite Binding Motif That May Constitute a Natural Metal-Oxide Binding Archetype.” Environmental Science and Technology 42(10):3821-3827.