Basics of Photoactivation

INTRODUCTION Specific molecular interactions control cellular function. The photorelease of caged compounds (nucleotides, neurotransmitters, peptides, second messengers, proteins, etc.) can be used to control these interactions in living cells. Caged compounds are biological effector molecules whose active functionality has been chemically masked with a photoremovable protecting group. Illumination produces a concentration jump from the caged molecule. This article discusses the basic principles underlying photoactivation, the properties of caging chromophores and commercially available caged compounds, and practical considerations for their effective use.