Offline MS/MS analysis for localizing the PTM sites, tri-methylation at Ala1, deamidation at Asn13, phosphorylation at Ser14 for rhesus macaque MLC-2S. Representative ECD and CAD fragment ions and sequence maps of (a) un-phosphorylated MLC-2S and (b) mono-phosphorylated MLC-2S. P, phosphorylation; (Me)3, tri-methylation; Dea, deamidation; N.D., not detected; Red circles, theoretical isotopic abundance distribution of the isotopomer peaks of c and z˙ ions; Blue circle, loss of 1 Da from the c ions presumably resulting from H rearrangement [41].