Table 2.

Peptide masses obtained by MALDI-TOF/MS of in-gel tryptic digests of 22-kDa hGH, 45-kDa hGH, or their reduced and alkylated derivatives

Expected mass of hGH tryptic peptide	Numeric order of tryptic peptide (T)in hGH sequence	Tryptic peptide’s range of residues in hGH	Amino acid sequence of hGH tryptic peptide	Observed mass of 22-kDa hGH tryptic peptide	Observed massa of 22-kDa hGH tryptic peptide	Observed mass of MER-45-kDa hGH tryptic peptide	Observed massa of MER-45-kDa hGH tryptic peptide
693.39	T13	135–140	TGQIFK	693.48	—	693.40	—
764.43	T19	173–178	VETFLR	764.52	—	—	—
773.38	T12	128–134	LEDGSPR	773.46	—	—	—
844.49	T8	71–77	SNLELLR	842.61	844.58	844.50	844.51
930.54	T1	1–8	FPTIPLSR	930.65	930.62	930.54	930.54
979.50	T2	9–16	LFDNAMLR	979.62	979.59	979.50	979.51
995.50	T2b	9–16	LFDNAMLR	995.61	995.59	995.50	995.50
1148.56	T16	159–167	NYGLLYCFR	1148.55	—	1148.55	—
1205.58	T16c	159–167	NYGLLYCFR	—	1205.69	—	1205.61
1253.62	T18–T19d	169–178	DMDKVETFLR	1253.78	1253.73	1253.60	1253.62
1269.61	T18–T19b,d	169–178	DMDKVETFLR	—	1269.73	1269.57	1269.64
1361.67	T11	116–127	DLEEGIQTLMGR	1361.87	1361.81	1361.66	1361.70
1377.67	T11b	116–127	DLEEGIQTLMGR	1377.85	1377.80	1377.63	1377.68
1489.69	T15	146–158	FDTNSHNDDALLK	1489.89	1489.83	1489.69	1489.73
2262.13	T10	95–115	SVFANSLVYGASDSNVYDLLK	2262.33	2262.36	2262.96	2262.18
2342.13	T4	20–38	LHQLAFDTYQEFEEAYIPK	2342.37	—	2341.98	2342.09
2673.26	T6c	42–64	YSFLQNPTSLCFSESIPTPSNR	—	—	—	2673.23
2676.25	T15–T16–T17d	146–168	FDTNSHNDDALLKNYGLLYCFRK	—	2676.40	—	—

^a Reduced and alkylated protein.

^b Oxidized methionine.

^c Alkylated peptide.

^d Incomplete cleavage.