(264f) Engineering Novel Proteins for the Sustainable Extraction of Rare-Earth Metals

Rare-earth elements (REEs) have applications in many consumer electronics such as motors and batteries. However, the current state-of-the-art extraction process is environmentally damaging due to the heavy use of acidic and organic solvents. The physiochemical similarity of the multiple REE species also complicates purification and no current extraction technique presents selectivity with the group. Recently, a protein was discovered that demonstrates preferential binding with REE ions as opposed to more biologically common species such as calcium. Named ‘lanmodulin’ due to its preference for lanthanides and its similarity to calmodulin, this protein has served as a starting point for our investigation into the design of metal-binding proteins that can selectively remove specific REEs of choice. Using both computational molecular modeling and experiment, we have begun to investigate which peptide characteristics lead to the observed REE affinity. Binding to specific protein domains has been characterized using UV/Vis spectroscopy. The next generation of engineered protein designs have been expressed via various synthetic biology techniques and it is hoped that this approach will yield a sustainable method to catch-and-release specific REE ions from new sources such as electronic and industrial wastes.