text: Its water-solubility, together with its status as the only known photoactive protein containing a carotenoid, makes the OCP a valuable model for studying solution-state energetic and photophysical properties of carotenoids, which are a diverse class of molecules found across all domains of life.  Moreover, carotenoids are widely investigated for their properties as anti-oxidants, and thus the protein may serve as a template for delivery of carotenoids for therapeutic purposes in human medicine.
  Because of its high efficiency of fluorescence quenching, coupled to its low quantum yield of photoactivation by specific wavelengths of light, OCP has ideal properties as a photoswitch and has been proposed as a novel system for developing optogenetics technologies  and may have other applications in optofluidics and biophotonics.