Development of Bacterial Display Peptides for use in Biosensing Applications

• Main Authors: Stratis-Cullum, Dimitra N, Kogot, Joshua M, Sellers, Michael S, Hurley, Margaret M, Sarkes, Deobrah A, Pennington, Joseph M, Val-Addo, Irene, Adams, Bryn L, Warner, Candice R, Carney, James P
• Format: Report
• Language: English
• Subjects: AFFINITY REAGENT; ANTIGENS; BACTERIA; BACTERIAL DISPLAY; Biochemistry; DOCKING; MULTI-SCALE MODELING; PEPTIDES; PROTEINS; SYNTHETIC REAGENT

Recent advances in synthetic library engineering continue to show promise for the rapid production of reagent technology in response to biological threats. A synthetic library of peptide mutants built off a bacterial host offers a convenient means to link the peptide sequence, (i.e., identity of individual library members) with the desired molecular recognition traits, but also allows for a relatively simple protocol, amenable to automation. An improved understanding of the mechanisms of recognition and control of synthetic reagent isolation and evolution remain critical to success. In this paper, we describe our approach to development of peptide affinity reagents based on peptide bacterial display technology with improved control of binding interactions for stringent evolution of reagent candidates, and tailored performance capabilities. There are four key elements to the peptide affinity reagent program including: (1) the diverse bacterial library technology, (2) advanced reagent screening amenable to laboratory automation and control, (3) iterative characterization and feedback on both affinity and specificity of the molecular interactions, and (3) integrated multiscale computational prescreening of candidate peptide ligands including in silico prediction of improved binding performance. Specific results on peptides binders to Protective Antigen (PA) protein of Bacillus anthracis and Staphylococcal Enterotoxin B (SEB) will be presented. Recent highlights of on cell vs. off-cell affinity behavior and correlation of the results with advanced docking simulations on the protein-peptide system(s) are included. The potential of this technology and approach to enable rapid development of a new affinity reagent with unprecedented speed (less than one week) would allow for rapid response to new and constantly emerging threats. The original document contains color images. Supported in part by DTRA Joint Science and Technology Office for Chemical and Biological Defense.