Bacterial display is an advanced service that links the function of a protein with the gene that encodes it. Creative Biolabs offers a unique bacterial display technology, for the identification of target-binding peptides.
Today, displaying of recombinant protein libraries are essential in many research areas, such as antibody screening, drug discovery, and protease substrate identification. Although phage display is still the most widely used method, alternative systems are available and are becoming increasingly popular.
Bacterial display (or bacteria display or bacterial surface display) is a protein engineering technique widely used for in vitro protein evolution. Libraries containing billions of diverse molecules polypeptides displayed on the surface of bacteria are screened using magnetic-activated cell sorting (MACS) or fluorescence-activated cell sorting (FACS). Peptide libraries can be constructed in Escherichia coli as insertions in extracellular proteins (such as pili or flagella subunits) or as insertions into outer membrane proteins for screening. The bacterial display system has been approved to be simple and efficient and has been applied extensively to find the affinity of a ligand for its target protein.
Figure 1. Identification of target-binding peptides from bacterial display peptide libraries (Getz et al. 2012)
With our extensive experience in bacterial display, we provide protein screening service by bacterial display. Our state-in-the-art technology enables the rapid isolation of target-specific proteins without the labor intensive screening. We provide several bacterial display scaffolds for library screening according to the sizes of passengers displayed, including OmpA, OmpX, FliTrx, FimH, CPX, Lpp (1-9) OmpA and nvasin (1-625).
The applications of bacterial display including but not limited to:
Rapid and simple methods for the epitope characterization as well as the antibody cross-reactivity with other proteins are great needed to generate well-validated, protein-specific diagnostic, and therapeutic antibodies. Creative Biolabs has established state-of-the-art bacterial display platform for epitope mapping services. This strategy will likely provide a means to enhance the specificity of ligand panels, since specificity can be measured directly using FACS.
The use of bacterial display provides a convenient means to identify ligands that mediate entry or invasion of target cells which can be further developed as drug targets. We identify cell-binding peptides by the help of FACS by co-expression of GFP to bacterial display libraries. We also developed a unique platform which enables quantitative screening via FACS for cell-specific ligands.
The use of bacterial display provides a convenient means to identify peptide substrates for proteolytic enzymes. Creative Biolabs has established two-color bacterial display system termed cellular libraries of peptide substrates (CLiPS) for the identification of optimal peptide substrates of protease.
The bacterial display is a well-established methodology for the discovery and optimization of peptides with binding functions. Our protein-binding ligand screening process allows real-time analysis of displayed peptide properties, including target-binding affinity, specificity, and peptide stability to proteases during screening. The ability to measure these properties enables efficient identification of peptides and allows direct evaluation of library population fitness.
Creative Biolabs has developed advanced anchored periplasmic expression (APEX) system to enable screening of antibody fragments, especially human scFv antibody. We have the ability to screen unique single-chain variable fragment (scFv) antibodies that have both high specificity and extremely high affinity, with Kd up to10-12 for the target antigen.