Identification of perrhenate-binding peptides by phage display

Pertechnetate is the most stable and highly environmentally mobile form of the radioactive element technetium. To explore the ability of peptides to remove this molecule from aqueous solutions, a phage display library was biopanned against immobilized perrhenate, a nonradioactive analog of pertechnetate. Six unique peptides were identified from the screen and their ability to bind perrhenate, both free in solution and immobilized on a solid support, was explored. It was found that the peptides, particularly when immobilized, were able to remove perrhenate from aqueous solutions, and despite not being screened for selectivity, demonstrated some preference for perrhenate over other anions such as chromate and nitrite. These results demonstrate the feasibility of using engineered biological systems for remediation of pertechnetate in the environment.