derives from O-phospho-L-threonine O-phospho-L-threonine with neutral loss of phosphate -97.976898193359375 -98.0 83.03711700439453125 83.089996337890625 PSI-MOD MOD:00439 Covalent modification of a peptide or protein amino acid phosphorylated threonine with a secondary loss of a neutral trihydrogen phosphate molecular fragment. C 4 H 5 N 1 O 1 MOD:00047 artifact none dPhosOPhosThr H -3 O -4 P -1 modified L-threonine residue phosphorylated residue with neutral loss of phosphate