2-(L-cystein-S-yl)-methionine -2.0156500339508056641 -2.0199999809265136719 232.034027099609375 232.3300018310546875 2-(L-cystein-S-yl)-methionine CROSSLNK 2-(S-cysteinyl)-methionine (Cys-Met) Cross-link 2. The chirality around the methionine alpha-carbon has not been determined. C, M A protein modification that effectively cross-links an L-cysteine residue and an L-methionine residue by a thioether bond to form 2-(L-cystein-S-yl)-methionine. none natural MOD:01857 PSI-MOD (2R)-2-amino-2-([2-amino-2-carboxyethyl]sulfanyl)-4-(methylsulfanyl)butanoic acid H -2 C 8 H 12 N 2 O 2 S 2 alpha-carbon thioether crosslinked residues crosslinked L-cysteine residue crosslinked L-methionine residue