S-(L-isoglutamyl)-L-cysteine (2S)-2-amino-5-[(2R)-2-amino-2-carboxyethyl]sulfanyl-5-oxopentanoic acid (S,R)-2-amino-4-[S-(2-amino-2-carboxyethyl)thiocarboxy]butanoic acid -17.026548385620117188 -17.030000686645507812 2-amino-5-(2-amino-2-carboxyethyl)thio-5-oxopentanoic acid 214.0412139892578125 214.2400054931640625 A protein modification that effectively crosslinks an L-cysteine residue and an L-glutamine residue by a thioester bond with the formation of S-(L-isoglutamyl)-L-cysteine and the release of ammonia. C 0 H -3 N -1 O 0 S 0 C 8 H 10 N 2 O 3 S 1 C, Q CROSSLNK Isoglutamyl cysteine thioester (Cys-Gln) Cross-link 2; DeltaMass calculates the mass difference from glutamic acid rather than glutamine. MOD:00117 PSI-MOD S-(L-isoglutamyl)-L-cysteine S-gamma-glutamyl (crosslinked to cysteine) XLNK-SCys-5Glu(Gln) gamma-(S-cysteinyl)glutamic acid natural uniprot.ptm:PTM-0156 thioester crosslinked residues crosslinked residues with loss of ammonia crosslinked L-glutamine residue