. 2010 Feb 13;397(8):3441–3455. doi: 10.1007/s00216-010-3471-8

Table 2.

Effect of oxidative modifications of Tyr on the mass defect and isotope pattern of angiotensin I (DRVYIHPFHL). The average and lowest monoisotopic masses of tryptic peptides (without missed cleavages) were calculated in 1-Da mass bins from a yeast protein database (http://www.yeastgenome.org; orf_trans.fasta database of 8 May 2009)

Modification	Chemical composition	Monoisotopic mass (M+H⁺, Da) and mass defect	Average tryptic peptide monoisotopic mass (M+H⁺, Da)	Lowest tryptic peptide monoisotopic mass (M+H⁺, Da)	Isotope masses and relative intensities
None	C₆₂H₉₀N₁₇O₁₄	1,296.6848 (0.52 mmu)	1,296.6475 (−0.0373 Da)	1,296.5526 (−0.1322 Da)	1,296.68 (100.0)
					1,297.69 (74.9)
					1,298.69 (30.6)
					1,299.69 (8.9)
					1,300.70 (2.0)
Hydroxy	C₆₂H₉₀N₁₇O₁₅	1,312.6797 (0.52 mmu)	1,312.6706 (−0.0091 Da)	1,312.5286 (−0.1511 Da)	1,312.68 (100.0)
					1,313.68 (74.9)
					1,314.69 (30.8)
					1,315.69 (9.1)
					1,316.69 (2.1)
Chloro	C₆₂H₈₉N₁₇O₁₄Cl	1,330.6458 (0.49 mmu)	1,330.6723 (+ 0.0265 Da)	1,330.5344 (−0.1114 Da)	1,330.65 (100.0)
					1,331.65 (74.9)
					1,332.65 (62.5)
					1,333.65 (32.8)
					1,334.65 (11.8)
					1,335.65 (3.2)
Bromo	C₆₂H₈₉N₁₇O₁₄Br	1,374.5953 (0.43 mmu)	1,374.6884 (+0.0931 Da)	1,374.5483 (−0.0470 Da)	1,374.60 (78.2)
					1,375.60 (58.6)
					1,376.60 (100.0)
					1,377.60 (63.9)
					1,378.60 (24.9)
					1,379.60 (7.1)
					1,380.60 (1.6)
Iodo	C₆₂H₈₉N₁₇O₁₄I	1,422.5814 (0.41 mmu)	1,422.7089 (+0.1275 Da)	1,422.5259 (−0.0555 Da)	1,422.58 (100.0)
					1,423.58 (74.9)
					1,424.59 (30.6)
					1,425.59 (8.9)
					1,426.59 (2.0)
Dibromo	C₆₂H₈₈N₁₇O₁₄Br₂	1,452.5058 (0.35 mmu)	1,452.7232 (+0.2174 Da)	1,452.5795 (+0.0701 Da)	1,452.51 (44.4)
					1,453.51 (33.3)
					1,454.50 (100.0)
					1,455.51 (68.7)
					1,456.50 (69.3)
					1,457.51 (39.3)
					1,458.51 (14.6)
					1,459.51 (4.1)