PROPIONYL AND BUTYRYL LYSINE MODIFICATIONS IN PROTEINS

摘要

While the identification of acetylated lysine residues on proteins is well-known, the modification of lysine residues through propionylation and butyrylation is not very well understood. A method for the identification and mapping of propionylated and butyrylated lysine residues has been developed. Anti-acetyllysine antibody, normally used to affinity purify a protein mixture based on the presence of acetylated lysine, can also be used to affinity purity proteins having propionylated and butyrylated lysine residues due to the structural similarity. The method involves searching protein databases to locate mass spectrometry datasets for those proteins purified by anti-acetyllysine antibody. The located spectra are manually reviewed to identify those peptides having propionyllysine and butyryllysine residues. These identified peptides are synthesized, with the lysine modifications added at the appropriate positions. The synthesized proteins are then analyzed with mass spectrometry and the resultant spectra are compared to those located in the protein databases to confirm the location of the lysine modifications.