Requirements for Display
What is needed for a display method?
An ideal platform for the discovery of peptide hits should be based on a peptide display technology that allows for the linkage of peptide genotype to phenotype, would be rapid and allow for the use of highly complex peptide libraries, and could display modified peptides that include macrocyclisations and other constraints, inclusion of unnatural amino acids, and other posttranslational modifications.
The type of genetic material encoding the peptide used by a peptide display technology may have implications for its usability, particularly the use of RNA as opposed to DNA with regards to stability.
Peptide display requires some form of carrier. This may be the genetic material that encodes it as in mRNA display, the surface of a cell as in yeast or bacterial display, or a microbead. Peptide copy number plays a role in the ability of a technology to capture low-affinity binders and therefore number of peptides displayed can be critical. The larger a carrier is the more copies of peptide can be displayed, but with the largest carriers like yeast and bacteria, the volumes may become unmanageable and therefore only small subsets of libraries can be utilised in a single screen.