A low-toxicity uranyl-selective-binding linear pentapeptide sequence as a potential uranium decorporation agent

Searching for highly selective, efficient, and low-toxicity chelating agents is central to resolving uranium contamination in vivo. Peptides composed of amino acids exhibit very low toxicity for accumulation in the human body and have been proven effective in chelating actinides within the human body. Herein, we report a rationally designed short phosphorylated peptide sequence PP-B, which exhibits high affinity and selectivity for uranyl compared to other trace elements present in the body (such as Na⁺, K⁺, Ca²⁺, Co²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Mn²⁺, Zn²⁺). The association constant for the peptide-uranyl complex is calculated to be 7.3 ×10⁵ M^-1. The result of DFT calculation shows that the phosphate group binds strongly to the UO₂ ²⁺ center, potentially accounting for the peptide's strong affinity towards UO₂ ²⁺. The results of in vivo uranyl decorporation assays reveal that PP-B has a much lower toxicity and a much higher decorporation efficiency than that of the clinically approved DTPA. These findings render PP-B a promising candidate for utilization as a novel decorporation agent.