A7-nitroTyr-MbPylRS

3-nitroTyr is a natural post-translational modification of proteins typically resulting from protein oxidation by peroxynitrite. It increases in many diseases and with age. Still unknown is if it can be reversed (by a denitrase) and if it has has a purposeful signaling role, or if it is only a modification associated with pathologies. It is known in some cases to contribute to disease pathology, but in most cases it is unknown how much it causes pathology vs. being a consequence of pathology. The ability to site specifically and quantitatively place 3-nitroTyr in positions in proteins that have been seen to occur in association with disease is a key tool to answer questions about its possible roles in normal physiology and disease.