m-azipropofol (aziPm) and azi-fropofol are photoactivatable analogues of propofol and fropofol, respectively as we previously stated (17 (link)). We equilibrated aziPm (final concentration 10 μM) or azi-fropofol (final concentration 50 μM) with TLR7 protein (1 mg/mL) for 10 min, followed by exposure to 350-nm light using a Rayonet RPR-3500 Lamp (Southern New England Ultraviolet Co., Branford, CT, USA). Then, the protein was subjected to electrophoresis on an SDS-polyacrylamide gel and Commassie staining. The excised protein gel band was subjected to trypsin digestion. Samples were injected into a nano-LC column with online electrospray into a LTQ linear ion trap (Thermo Fischer Scientific). Xcalibur (Thermo Fischer Scientific) was used for data acquisition, and Sequest (Scripps Research Institute, La Jolla, CA, USA) was used to search for the sequence of TLR7 with an aziPm or azi-fropofol mass modification. To confirm the specificity of aziPm or azi-fropofol, competition assay was done by photolabeling TLR7 protein with aziPm or azi-fropofol in the presence of propofol (200 μM) or fropofol (100 μM), respectively.