Photoactivated peptide

[7][8][9] Photoactivated peptides have shown potential for various applications, including cancer therapy, other light-controlled drugs, and as tools to probe molecular interactions in intact cells and whole organisms.

Specifically, a synthetic short peptide was alkylated with azobenzene crosslinkers and used to photo-stimulate mitochondrial membrane depolarization and cytochrome c release in permeabilized cells, initiating the intrinsic apoptosis pathway.

[8] Analogs of Gramicidin S containing a diarylethene fragment[6] have also been developed, exhibiting a clear, reversible change in antimicrobial activity.

In their inactive, UV-inducible photoform, these analogs are harmless to bacteria cells; however, upon activation with visible (amber) light, they become bactericidal.

Additionally, a photoswitchable analogue of the orexin-B peptide has been developed, enabling control of orexin receptors with light in vivo at nanomolar concentrations.

Schematic representation of activation/deactivation of a photoswitchable peptide
A cartoon of a peptide with an azobenzene dye attached to the sidechains of cysteine residues. Exposure to 360 nm light causes photoisomerization of the diazo dye from E to Z , shortening it and encouraging a more alpha-helical conformation