Development and Characterization of Light-Responsive Peptide Macrocycles.

Small molecules, peptide macrocycles, and protein conjugates that reversibly turn their function on and off in response to visible light enabled the fields of photopharmacology and optochemical genetics. In this chapter, we describe a method for the synthesis of light-responsive (LR) macrocycles from linear peptides composed of 20 natural amino acids. Bioactive LR molecules can be produced by grafting azobenzene or other LR-structures onto molecules with known biological functions (e.g., alpha-helical peptides). The resulting macrocyclic peptide contains two loops of amino acids, which is constrained with an azobenzene moiety that can change the conformation in response to visible light.