Cell Surface Display

Offers the advantage of analysis using optical methods

Since the first reports of bacterial display of heterologous proteins in 1986, an extraordinary number of different display systems have been established for yeasts, grampositive and gramnegative bacteria. These systems have been employed for a wide range of biotechnical and biomedical applications and have prompted substantial progress in whole cell biocatalysis, live vaccine development, biosorbent and biosensor development, epitope mapping, antigen delivery, inhibitor design, and protein/peptide library screening.

The display of a protein or peptide with a distinct function at the cellular surface bears considerable advantages for many biotechnical applications. The molecule displayed at the cell surface is freely accessible for the substrate or binding partner in activity or binding studies. Proteins have proven to be more stable when connected to a matrix rather than as free molecules. In this case, the cell envelope acts as a matrix. By displaying proteins on the cell surface, preparing or purifying the protein also becomes redundant in many instances.

Whole cells displaying the molecule of interest can be used in reactions or analytical assays. Removing the cells is then simply possible via centrifugation. Bacterial cell surface display exhibits another significant advantage during the creation and screening of peptide or protein libraries. The gene corresponding to the protein or peptide displayed on the cell surface is co-selected and can easily be cloned for rapid sequence determination, initial structural predictions, and various other studies and applications. Due to the larger size of bacterial or yeast cells, in comparison to phages, cell surface display offers the advantage of being analyzable using optical methods including fluorescence microscopy, or high-throughput methods, such as fluorescence-activated cell sorting (FACS).