ester crosslinked residues crosslinked residues with loss of water O-glycyl-L-serine (2S)-2-amino-3-[(aminoacetyl)oxy]propanoic acid -18.010564804077148438 -18.020000457763671875 143.0456695556640625 143.1199951171875 A protein modification that effectively crosslinks an L-serine residue and a glycine residue by an ester bond to form O-glycyl-L-serine. C 0 H -2 N 0 O -1 C 5 H 7 N 2 O 3 C-term CROSSLNK Glycyl serine ester (Gly-Ser) (interchain with S-...) CROSSLNK Glycyl serine ester (Ser-Gly) (interchain with G-...) Cross-link 2. G, S MOD:01585 O-(glycyl)-L-serine O3-(aminoacetyl)serine PSI-MOD natural serine glycinate ester uniprot.ptm:PTM-0422 crosslinked glycine residue crosslinked L-serine residue