. Author manuscript; available in PMC: 2012 Feb 18.

Published in final edited form as: Chem Res Toxicol. 2011 Jan 7;24(2):204–216. doi: 10.1021/tx100275t

Table 6.

Modifications Observed in “DNA-Histones” Data set.

mass	residues	modification name^a	peptides	spectra
−17	Q	Pyro-glutamic acid	6	189
22	E, D, S, T, G	Sodium adduct	47	128
12	N-terminal residues: W, H, S	N6-formyl	8	78
28	K, R, and N-terminus	Dimethylation or formylation	19	68
42	K and N-terminus	Acetylation	24	66
43	K and N-terminus	Carbamylation	7	30
48	C	Cysteic acid	9	21
86	K	Diepoxybutane adduct (Epoxide)	7	15
16	F	Oxidation	5	10
70	K	Unexpected	8	9
178	K	1,2-dibromoethane+DNA	2	9
76	C	Unexpected	4	6
14	D	Methylation	3	6
104	K	Diepoxybutane adduct (Triol)	3	5
223	C	Unexpected*	1	5
32	W	Dioxidation	2	2

^(a)

UniMod annotation corresponding to the most frequently observed modification mass. Alternative modification names were included for ambiguous mass shifts. Asterisk denotes single peptide modifications with strong spectral evidence (see Supplemental File 10).