Application of iTRAQ Reagents to Relatively Quantify the Reversible Redox State of Cysteine Residues

Table 3

A selection of peptides identified from the Gram-negative bacteria, B. subtilis with relative quantification of the redox state of identified cysteine peptides. Total detectable thiols refer to both reversibly oxidized and reduced thiols and quantification is relative to control values. As overoxidized thiols are not amenable to selection they are not detected in controls (N.D.).

Protein (accession number)	Cys tryptic peptide	Total detectable thiols (%)	Sample	Reversibly oxidized thiols (%)	Free thiols (%)	Overoxidized thiols (%)
Triose phosphate isomerase (Q65ENO)	^85DLGVEYCVIGHSER^98	100	Control	41	59	N.D.
			Test	35	32	33
	^179SSTSEDANEMCAHVR^193	100	Control	51	49	N.D.
			Test	52	32	17
Elongation factor Ts (Q65JJ8)	^15TGAGMMDCK^23	100	Control	53	47	N.D.
			Test	52	8	40
	^234YFEEICLLDQAFVK^247	100	Control	66	34	N.D.
			Test	44	4	52
Elongation factor G (Q65PB0)	^595CNPVILEPISK^605	100	Control	85	15	N.D.
			Test	75	−10	25
	^381DTTTGDTLCDEK^392	100	Control	95	5	N.D.
			Test	30	−6	75
Elongation factor Tu (Q5P334)	^138CDMVDDEELLELVEMEVR^155	100	Control	117	(−17)	N.D.
			Test	91	−1	8
	^76HYAHVDCPGHADYVK^90	100	Control	173	(−73)	N.D.
			Test	150	(−41)	−50
Adenylate kinase (P35140)	^75NDCDGGFLLDGFPR^88	100	Control	94	4	N.D.
			Test	68	1	31
Purine nucleoside phosphorylase (Q65IE9)	^27YIADTYLENVECYNEVR^43	100	Control	91	9	N.D.
			Test	50	9	41
Transition state regulatory protein AbrB (P08874)	^50YKPNMTCQVTGEVSDDNLK^68	100	Control	39	61	N.D.
			Test	46	23	31