Advanced Laser Photolysis of Caged Compounds

Caged compounds are biologically active molecules that have been rendered inert by the introduction of a photolabile protecting (caging) group to an important functional group. The intracellular photolysis of the caging group to reveal the active compound provides a powerful method for the intracellular release of biologically important molecules with exquisite temporal and spatial control. This technique therefore provides an ideal noninvasive tool for the study of many chemical, physiological and biological systems. The photolabile protecting groups used to cage the active compounds were first developed in the 1960’s for use in organic synthesis processes but were quickly adopted by biologists in the 1970’s to cage biologically relevant molecules such as ATP. Since then numerous compounds including chelators, neurotransmitters, fluorescent dyes, peptides, nucleotides, second messengers and enzymes have been caged using a variety of caging groups [1].