Implementing In-Cell Fast Photochemical Oxidation of Proteins in a Platform Incubator with Movable XY Stage

Fast photochemical oxidation of proteins (FPOP) is a protein footprinting technique that is being increasingly used in MS-based proteomics. FPOP is utilized to study protein-protein interactions, protein-ligand interactions, and protein conformational dynamics. This method has recently been extended to protein labeling in live cells (IC-FPOP), allow-ing the study of protein conformations in the complex cellular environment. Traditionally, IC-FPOP has been executed using a single cell flow system in which hydrodynamic focusing drives cells along in a single file line keeping the cells from clumping thus ensuring equal exposure to the laser irradiation required for photochemical oxidation. Here, we introduce a novel platform that allows IC-FPOP to occur in a sterile incubation system complete with mobile stage for XY movement, peristaltic pumps equipped with perfusion lines for chemical transport, and mirrors for laser beam guidance. This new system, called Platform Incubator with movable XY stage (PIXY), a...