Accelerating phage-display library selection by reversible and site-specific biotinylation

• Published in: Protein engineering, design and selection Vol. 22; no. 11; pp. 685 - 690
• Main Authors: Koide, Akiko, Wojcik, John, Gilbreth, Ryan N., Reichel, Annett, Piehler, Jacob, Koide, Shohei
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.11.2009
• Subjects: Adsorption; Amino Acid Sequence; Binding Sites; Biotinylation; directed evolution; Epitopes - chemistry; Epitopes - metabolism; Fibronectins - chemistry; Fibronectins - metabolism; Fungal Proteins - chemistry; Fungal Proteins - metabolism; high-throughput selection; Histidine - chemistry; Histidine - metabolism; Immobilized Proteins - chemistry; Immobilized Proteins - metabolism; Models, Molecular; Molecular Sequence Data; monobodies; Nitrilotriacetic Acid - chemistry; Nitrilotriacetic Acid - metabolism; Original articles; Peptide Library; Protein Structure, Secondary; Substrate Specificity; SUMO-1 Protein - chemistry; SUMO-1 Protein - metabolism; synthetic binding proteins; synthetic binding proteins; high-throughput selection; directed evolution; monobodies
• ISSN: 1741-0126; 1741-0134
• DOI: 10.1093/protein/gzp053

Immobilization of a target molecule to a solid support is an indispensable step in phage display library sorting. Here we describe an immobilization method that addresses shortcomings of existing strategies. Our method is based on the use of a polyhistidine-tagged (His-tagged) target molecule and BTtris-NTA, a high-affinity capture reagent for His-tags that also contains a biotin moiety. BTtris-NTA provides a stable and reversible linkage between a His-tag and a streptavidin-coated solid support. Because His-tags are the de facto standard for recombinant protein purification, this method dramatically simplifies target preparation for phage display library sorting. Here, we demonstrate the utility of this method by selecting high-affinity binding proteins based on the fibronectin type III (FN3) scaffold to two His-tagged protein targets, yeast small ubiquitin-like modifier and maltose-binding protein. Notably, a significant number of FN3 clones binding either targets selected using the new immobilization method exhibited only very weak binding when the same target was immobilized by coating on a polystyrene surface. This suggests that the His-tag-mediated immobilization exposes epitopes that are masked by commonly used passive adsorption methods. Together, these results establish a method with the potential to streamline and enhance many binding-protein engineering experiments.