Table 1. Detection of Cys-containing EC-SOD peptides in fractions from tryptic digest.

Fraction no.	Cys45*	Cys107	Cys189/190/195	Unreduced mass (m/z)†
aEC-SOD
F12	Arg-35—Arg-59	Ala-94—Arg-134	Leu-187—Arg-202 (+IAA)‡	8,789.94 (8,789.73)
			Arg-186—Arg-202 (+IAA)	8,945.89 (8,945.92)
iEC-SOD
F4	Asp-36—Arg-59 (+IAA)	N.D.	N.D.	2,537.04 (2,537.17)
	Arg-35—Arg-59 (+IAA)			2,693.12 (2,693.27)
F5	Asp-36—Arg-59 (+IAA)	N.D.	N.D.	2,507.02 (2,507.16)
	Arg-35—Arg-59 (+IAA)			2,663.09 (2,663.26)
F17	N.D.	Ala-94—Arg-134	Arg-186—Arg-202	6,251.57 (6,252.08)
			Leu-187—Arg-202	6,095.70 (6,095.89)
F18	N.D.	Ala-94—Arg-134	Arg-186—Arg-202	6,251.55 (6,252.08)
F19	N.D.	Ala-94—Arg-134	Leu-187—Arg-202	6,095.19 (6,095.89)

Fractions indicated in Fig. 5 were reduced and analyzed by MALDI-MS. The detected peptides containing the indicated Cys residues are listed. Incomplete digestion by trypsin is indicated in italics. N.D., Not detected.

^*The tryptic peptide containing Cys-45 encompasses a Thr/Ala polymorphism at position 40.

^†The mass of unreduced material was determined by ESI-MS. Calculated mass is given in parentheses.

^‡Mass increase due to alkylation (+57 Da) is indicated by +IAA in parentheses.