methylamine Michael addition derivatized residue modified L-serine residue methylamine Michael addition derivatized serine 100.06365966796875 100.12000274658203125 13.031634330749511719 13.039999961853027344 A protein modification that effectively converts an L-serine residue to 2-amino-3-(methylamino)propanoic acid. C 1 H 3 N 1 O -1 C 4 H 8 N 2 O 1 In PubMed:11743741 phosphoserine is converted to dehydroalanine in base, then by Michael addition of methylamine to 2-amino-3-(methylamino)propanoic acid. MOD:01302 Methylamine Michael addition with methylamine PSI-MOD S Unimod:337 artifact