Modification of the loops in the ligand-binding site turns avidin into a steroid-binding protein.

Background: Engineered proteins, with non-immunoglobulin scaffolds, have become an important alternative to antibodies in many biotechnical and therapeutic applications. When compared to antibodies, tailored proteins may provide advantageous properties such as a smaller size or a more stable structure.

Results: Avidin is a widely used protein in biomedicine and biotechnology.