(304e) Improving Cerium (III) Ion Binding Affinity of Designed Peptides Based on EF-1 Hand Loop of Lanmodulin
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Separations Division
Advances in Bioseparations
Wednesday, November 8, 2023 - 4:42pm to 5:00pm
In the present work, we designed several peptides based on the EF-1 hand loop of Lanmodulin to improve the REE ion binding affinity, specifically targeting modulation of entropy in the process. Circular dichroism (CD) and isothermal titration calorimetry (ITC) experiments were performed to confirm binding and estimate the thermodynamic properties such as ÎG, ÎH, ÎS, dissociation constant (Kd), and binding sites (N). It is found that all designed peptides have REE ion binding affinity, where ÎG is negative and ÎH and ÎS are positive, confirming the binding is entropy-driven. The estimated dissociation constant (KD) values range from around 1.0 µM and 10 µM by sequence-defined tuning of ÎS. A significant structure-function mathematical relationship can be drawn between amino acid content and ÎS. The insights captured in this study will help design peptides that span an order of magnitude in Kd which is important in developing peptide-grafted polymeric membranes for REE separation processes.