Tarrago, LionelPéterfi, ZalánLee, Byung CheonMichel, ThomasGladyshev, Vadim2015-12-042015Tarrago, Lionel, Zalán Péterfi, Byung Cheon Lee, Thomas Michel, and Vadim N. Gladyshev. 2015. “Monitoring methionine sulfoxide with stereospecific mechanism-based fluorescent sensors.” Nature chemical biology 11 (5): 332-338. doi:10.1038/nchembio.1787. http://dx.doi.org/10.1038/nchembio.1787.1552-4450http://nrs.harvard.edu/urn-3:HUL.InstRepos:23845301Methionine can be reversibly oxidized to methionine sulfoxide (MetO) under physiological and pathophysiological conditions, but its use as a redox marker suffers from the lack of tools to detect and quantify MetO within cells. In this work, we created a pair of complementary stereospecific genetically-encoded mechanism-based ratiometric fluorescent sensors of MetO by inserting a circularly yellow fluorescent protein between yeast methionine sulfoxide reductases and thioredoxins. The two sensors, named MetSOx and MetROx for their ability to detect S and R-forms of MetO, respectively, were utilized for targeted analysis of protein oxidation, regulation and repair, as well as for monitoring MetO in bacterial and mammalian cells, analyzing compartment-specific changes in MetO, and examining responses to physiological stimuli.en-USJournal Article2015-12-0410.1038/nchembio.1787