Light-activated proteins.

A wide assortment of caged compounds, which are species whose biological activity can be unleashed with light, have been synthesized and used to investigate a variety of biological phenomena. In contrast, the construction of caged proteins and their application to biological systems has lagged far behind. Recent advances in the synthesis of caged proteins, as well as the development of intracellular protein delivery systems, furnish a framework upon which light-activated proteins can be designed, synthesized and employed to address questions of biological significance.