Table 1. Gluten peptides containing cysteine, S-carbamidomethyl cysteine, or S-β-(4-pyridylethyl) cysteine, detected by LC-MS/MS after chymotryptic digestion of a reduced/unalkylated or reduced/alkylated protein extract of wheat flour (cv. Akteur).

	Reduction				Alkylation with iodoacetamide				Alkylation with 4-vinylpyridine
Amino acid sequence	Mr	M/z	Score	RT (min)	Mr	M/z	Score	RT (min)	Mr	M/z	Score	RT (min)
ALETLPAMCNVY					1380.6	691.3	24	55.1	1428.7	715.4	19	50.1
CCQQL					707.3	708.2	44	18.4
CCQQLL					820.4	821.3	68	33.9
CCQQLW					893.4	894.3	63	41.3
CNVY									602.3	603.3	17	16.9
CSTTIAPF					895.4	896.4	19	45.1
CSVNVPL									835.4	836.3	30	36.0
CTIAPF					707.3	708.3	34	44.6	755.4	756.3	35	37.9
CTIAPVGF					863.4	864.4	59	48.6	911.5	456.8	78	42.5
CTIAPVGIF					976.5	977.5	47	58.9	1024.5	513.3	34	51.6
ELEACQQVVDQQL									1606.8	804.3	15	23.1
GQCSF					597.2	598.2	25	20.9
GQCVSQPQQQL					1271.6	636.8	40	28.4	1319.6	660.9	20	25.6
GQCVSQPQQQSQQQL					1742.8	872.4	53	27.4
IPCMDVVL									993.5	497.9	20	51.3
IPEQSRCQAIH	1280.6	641.4	17	22.2
LGECCSRL					993.4	497.7	68	25.9
LLQQCNPVSL									1218.6	610.4	22	41.7
LQQCNPVSL					1057.5	529.7	44	39.1	1105.6	553.9	42	35.2
LQQQCIPVAM									1234.6	618.3	16	40.6
NPCKNFL					891.4	446.8	24	17.6
QCEREL					833.4	417.7	39	15.9
QCERELQEL					1203.6	602.7	136	32.4
QQCNPVSL					944.4	945.4	46	34.7
QQLNPCKL	942.5	943.4	15	38.4
QQQLIPCMDVVL					1442.7	722.4	30	66.7	1490.8	746.4	16	60.4
QQQLNPCKNIL					1354.7	678.4	28	29.2
SQQQPCSQQQQQPL					1683.8	842.9	534	25.4	1731.8	578.4	71	23.4
SQVCF					639.3	640.2	23	32.1
VPPDCSTINVPY					1360.6	681.3	22	46.5
VPPECSIM									979.5	490.8	25	34.5
WQSSCH					803.3	804.3	17	43.2
YPSVTCPQQVSY	1370.6	686.3	20	45.3	1427.6	714.9	47	41.9	1475.7	738.8	42	38.8