L-cysteine oxazoline-4-carboxylic acid (4S)-2-[(1R)-1-amino-2-sulfanylethyl]-4,5-dihydro-1,3-oxazole-4-carboxylic acid -18.010564804077148438 -18.020000457763671875 172.0306549072265625 172.1999969482421875 2-[1-azanyl-2-sulfanylethyl]-4,5-dihydro-1,3-oxazole-4-carboxylic acid A protein modification that effectively crosslinks an L-cysteine residue and an L-serine residue to form L-cysteine oxazoline-4-carboxylic acid. C 0 H -2 N 0 O -1 S 0 C 6 H 8 N 2 O 2 S 1 C, S CROSSLNK Oxazoline-4-carboxylic acid (Cys-Ser) Cross-link 2. L-cysteine oxazoline-4-carboxylic acid MOD:00244 PSI-MOD natural uniprot.ptm:PTM-0381 crosslinked residues with loss of water oxazole/oxazoline ring crosslinked residues (Ser) crosslinked L-cysteine residue