Table 1.

Examples of large-scale mass spectrometry analysis of protein methylation

Enrichment	Type of Mass spectrometer	Separation method	Number of identified methylated peptides/proteins	Labeling-method	Reference
Methyl-arginine (R)-specific antibody	Q-exactive	HILIC1	Methyl-R sites: 215 Novel methyl-R sites:171	Methyl-SILAC	[28]
		SCX2	Methyl-R sites: 39 Novel Meth-R sites: 25
		IEF3	Methyl-R sites: 66 Novel methyl-R sites: 34
			Total number of methyl-R: 249 sites (190 novel sites) Methylated proteins: 131 (93 not previously described as methylated proteins)
Methyl-arginine (R)- specific antibody	Q-TOF	Gel-based	Methylated sites: 59 Methylated proteins: 33	Methyl-SILAC	[25]
	LTQ-FT
Methyl-lysine (K)- specific antibody
Methyl-arginine (R)-specific antibody	Q-Star	Gel-based	Methylated proteins: 200	Label-free	[27]

¹HILIC Hydrophilic Interaction Chromatography,

²SCX Strong Cation Exchange,

³IEF Isoelectric Focusing