A mass spectrometry based method for distinguishing between symmetrically and asymmetrically dimethylated arginine residues.

摘要: The arginine methylation of proteins is involved in several important cellular activities, most notably transcriptional control. Arginine dimethylation can take two distinct forms, symmetric and asymmetric, catalyzed by different classes enzymes. To establish a method for the mass spectrometric identification characterization this post-translational modification, we analyzed synthetic peptides with symmetrically or asymmetrically methylated residues electrospray ionization tandem spectrometry. We observed abundant characteristic ions at [M+nH-31](n+) [M+nH-70](n+) spectra [M+nH-45](n+) peptides. speculate these arise from neutral loss monomethylamine, dimethylcarbodiimide, dimethylamine, respectively. These allowed rapid arginine-dimethylated peptide myelin basic protein SmD3 co-immunoprecipitated methyltransferase-associated pICln, suggesting that may provide means to screen characterize dimethylarginine sites.