L-methionine sulfone 163.0303192138671875 163.1999969482421875 31.989828109741210938 32.0 dihydroxy (2S)-2-amino-4-(methylsulfonyl)butanoic acid O 2 suphonem DeltaMass gives the formula C 5 H 9 N 3 O 1 S 1 with mass 163 MOD:00256 natural MethionylSulphone Oxidation of Methionine (to Sulphone) Dioxidation L-methionine S,S-dioxide M A protein modification that dioxygenates an L-methionine residue to L-methionine sulfone. MetO2 C 5 H 9 N 1 O 3 S 1 L-methionine sulfone PSI-MOD none S,S-dioxymethionine MOD_RES Methionine sulfone sulfur oxygenated L-methionine sulfur dioxygenated residue