Photochemical regulation of an artificial hydrolase by a backbone incorporated tertiary structure switch

A stilbene chromophore has been incorporated into the turn region of a 42 amino acid peptide, linking two helical peptide sections. Spatial proximity between these sections, as well as aggregation into dimers, is required to facilitate the catalytic function of this artificial hydrolase. Photomodulation of the hydrolase activity results in an increase of the activity of 42 % upon switching from the trans to the cis isomer of the chromophore. This is rationalized by a change in the aggregation state of the peptidomimetic, which is supported by diffusion coefficients obtained from PFG-NMR experiments. The results show that incorporation of a small, relatively flexible chromophore into a large peptide is capable of inducing a considerable change in tertiary structure and thus, functionality.