Chromatopanning for the identification of gallium binding peptides

This study is concerned with a chromatography-based approach for the recovery of gallium binding peptide sequences from a recombinant phage display library.
The phage display technology is a promising tool for the identification of highly specific peptide biosorbents for the recognition and binding of gallium in aqueous solutions. However, the success of the peptide selection strongly depends on the chosen biopanning method. Stable target immobilization, as well as low unspecific interactions is a prerequisite for the enrichment of strong binding peptides. The underlying procedure of phage clone selection is sophisticated but has many advantages for biopanning experiments using metal ions as a target, such as an enhanced monitoring of process conditions and fractionation of eluates.
Here we report about the development of chromatography-based biopanning methods for gallium as target ion and the enrichment of putative gallium binding clone types.
The methods meet the requirements for stable immobilization of the target metal ions during the entire biopanning process and complete recovery of well interacting bacteriophage clones.
Phage clones expressing the peptide sequences TMHHAAIAHPPH, SQALSTSRQDLR and HTQHIQSDDHLA were identified and characterized to bind >10 fold better to a target that presents immobilized gallium ions, thus being promising sequence motifs for the development of peptide-based biosorbents.