[P002] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P01-022] A Scalable Pipeline to Identify Proteins with Strong and Selective Rare-Earth Elements (REEs) Binding Capacity

○Poh Ying Theng^1,2, Bo Xue^1,2, Ping Han^1,2, Wen Shan Yew^1,2 (1. Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS) (Singapore), 2. NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI) (Singapore))

Keywords:

Rare-earth elements binding protein discovery

Rare earth elements (REEs) are essential for clean-energy and high-tech devices, yet separating them from one another remains difficult and often environmentally harmful. This work aims to identify protein-based ligands with strong affinity and discriminative intra-REE selectivity to enable cleaner, more efficient separations. We seeded a sequence similarity network (SSN) with two lanmodulins, Mex-LanM (from Methylobacterium extorquens) and Hans-LanM (from Hansschlegelia quercus)—to prioritize candidates related to known REE binders. Screening was performed on crude cell lysates using a high-throughput xylenol orange colorimetric assay and the proteins of top performers were purified for subsequent xylenol orange–based titration assays to characterise their binding and selectivity profiles. Multiple candidates exhibited distinctive intra-REE preferences and comparatively strong REE-binding capacity in competition with xylenol orange, suggesting a potential for separating closely related lanthanides. However, as the assay determines binding under defined buffer and competition conditions, it may not directly translate to process environments. Further validation methods, including isothermal titration calorimetry, structural analysis, and testing in complex matrices, are needed to verify their selectivity, stability, and scalability. Overall, this sequence-guided, high-throughput pipeline rapidly uncovers and prioritizes REE-binding proteins with intra-REE selectivity and highlights protein ligands as promising tools for greener, more selective REE separations.