Streptavidin and avidin recognize peptide ligands with different motifs

Using streptavidin as a molecular target for synthetic peptide library screening, ligands with consensus sequences of HPQ and HPM were rapidly identified. Here, we report the discovery of several non-HPQ sequences that were found when a pentapeptide library that lacked histidine was used in the screen. Although the high-affinity natural ligand for both streptavidin and avidin is biotin, neither HPQ nor HPM sequences were discovered when avidin was used in the screen. Instead, a new motif, HP(Y/F)P, was identified. Data obtained from such peptide library screens will help us to better understand molecular recognition.