Chimeric Streptavidins as Host Proteins for Artificial Metalloenzymes

The streptavidin scaffold was expanded with well-structured naturally occurring motifs. These chimeric scaffolds were tested as host for biotinylated catalysts as artificial metalloenzymes (ArM) for asymmetric transfer hydrogenation, ring closing metathesis and anion- π catalysis. The additional second coordination sphere elements significantly influence both the activity and the selectivity of the resulting hybrid catalysts. These findings lead to identify propitious chimeric streptavidins for future directed evolution efforts of artificial metalloenzymes.