Let the peptides shine: SOX (Sulfonamido-OXine)-labelled peptides for direct kinase and phosphatase monitoring

and undergo Chelation-Enhanced Fluorescence (CHEF), have emerged as a convenient class of modular kinase sensors. The development of an array of SOX-peptides has allowed researchers to gain insights into biological processes including binding events, conformational constraints, enzyme activities, protein trafficking and localization. This focused review provides an overview of the use of SOX-labelled peptides for probing kinase and phosphatase activity in real-time assays, including their development, synthesis, applications and strengths and weaknesses compared to other kinase assays.