Table 3.

Chemical and enzymatic labelling of proteins or peptides ^a.

Reactive groups	Methods	Targets	Amino Acids	nb of samples	References
Thiol	ICAT	proteins	cysteine	2	[83]
	ALICE	proteins	cysteine	2	[97]
	Photocleavable-ICAT	proteins	cysteine	2	[98]
	N-ethymaleimide/iodoacetamide	proteins	cysteine	2	[99]
	acrylamide or vinylpyridine	proteins	cysteine	2	[100,101]
Amino	ICPL	proteins	N-term/Lys	2,3,4	[102,103]
	Post-digest ICPL	peptides	N-term/Lys	2	[104]
	iTRAQ	peptides	N-term/Lys	2,4,8	[105]
		/proteins			[106]
	TMT	peptides	N-term/Lys	2,6	[107]
	Dimethyl	peptides	N-term/Lys	2,4	[108,109]
Carboxyl	EMOS	proteins	C-term	2	[110,111,112]
		peptides	C-term	2	[113]
	AMOS	peptides	C-term	2	[114]
	Methanol	peptides	C-term/	2	[115]
			Asp/Glu

^a ICPL, isotope-coded protein label; TMT, tandem mass tags; ICAT, isotope-coded affinity tags; iTRAQ, isobaric tags for relative and absolute quantification; ALICE, acid-labile isotope-coded extractants; EMOS, enzyme mediated oxygen substitution; AMOS, acid mediated oxygen substitution.