Chapter 35: Chromophore-Assisted Light Inactivation: A Powerful Tool to Study Protein Functions

Chromophore-assisted light inactivation (CALI) is a method of directed inactivation of a protein of interest to study its functions. In CALI, the protein is tagged with a chromophore-photosensitizer and illuminated by light. This results in local production of reactive oxygen species (ROS), which damage the target protein. The use of light ensures extremely high spatial and temporal resolution in protein inactivation experiments. This is a distinct feature of CALI compared to other methods of protein inactivation such as gene knockout, RNA interference and chemical inhibitors or blocking antibodies. This chapter provides an overview of existing techniques of CALI implementation, namely CALI with antibody-targeted, genetically targeted and genetically encoded photosensitizers. Advantages and shortcomings of each approach, as well as future perspectives of CALI development are discussed.