Table 2.

Identification of phosphorylation sites on human cardiac troponin-I using LC-MS/MS analysis.

Peptide Sequence	Phosphorylated Residue	# Phosphorylated Peptides	Calculated Mol. Mass	Observed m/z	Observed Mol. Mass	Error ppm	Identity Score	Expect	Charge
21RRSSNYR27	S23/24	2	1097.4168	549.7153	1097.4160	−0.76	44	3.5E-03	+2
				549.7153	1097.4160	−0.71	41	6.9E-03	+2
46KLQLKTLLLQIAK58	T51	3	1588.9681	795.4868	1588.9591	−5.65	54	7.7E-05	+2
				530.6605	1588.9596	−5.32	46	4.2E-04	+3
				795.4870	1588.9595	−5.37	32	1.2E-02	+2
51TLLLQIAKQELER63*		1	1633.8804	817.9432	1633.8719	−5.17	50	2.3E-03	+2
118VTKNITEIADLTQK131	T119	3	1652.8386	827.4221	1652.8296	−5.41	79	7.6E-06	+2
				827.4241	1652.8336	−3.03	78	1.1E-05	+2
				827.4225	1652.8305	−4.87	86	6.7E-07	+2
121NITEIADLTQKIFDLR136*	T123	1	1968.9921	985.5000	1968.9854	−3.39	74	2.2E-05	+2
146RVRISADAMMQALLGAR162	S150	2	1937.9692	647.0000	1937.9782	4.62	54	3.6E-03	+3
				646.9972	1937.9697	0.24	59	8.3E-04	+3
147VRISADAMMQALLGAR162		6	1797.8630	891.9428	1781.8711	−0.17	76	2.4E-05	+2
				594.9632	1781.8678	1.65	48	9.6E-02	+3
				594.9639	1781.8698	1.22	79	1.3E-05	+3
				891.9424	1781.8703	0.95	44	3.9E-02	+2
				891.9436	1781.8727	2.54	65	3.2E-04	+3
				594.9645	1781.8715	1.92	53	5.3E-03	+2
149ISADAMMQALLGAR162		3	1526.6986	764.3565	1526.6985	−0.08	95	1.3E-07	+2
				764.3567	1526.6988	0.15	92	1.2E-07	+2
				764.3565	1526.6985	−0.09	62	1.3E-04	+2
163AKESLDLR170	S166	2	1010.4797	506.2469	1010.4792	−0.48	54	2.8E-03	+2
				506.2469	1010.4793	−0.45	41	5.0E-02	+2
194NIDALSGMEGR204*	S199	1	1257.5060	629.7601	1257.5056	−0.31	33	6.4E-02	+2

S, serine; T, threonine; ^*Indicates single detection event data.