TABLE 1.

Theoretical and observed monoisotopic mass values for peptide fragments that included Cys-82

Peptide fragments that included Cys-82 and a disulfide-linked peptide were obtained from wild-type nucleotide-free EF-Tu that had been incubated with 1 mm DTT or 0.5 mm H₂O₂ as reducing or oxidizing conditions, respectively.

Condition	Peptide including Cys-82		Peptide including Cys-82–Cys-82
	Mass	Differencea	Mass	Difference
Expected	1768.24		3421.52
Reducing	1768.88	+0.64	NDb
Oxidizing	ND		3420.91	−0.61

^a Difference between given and expected values.

^b ND, not detected.