282574.fig.0011a
(a)
282574.fig.0011b
(b)
282574.fig.0011c
(c)
282574.fig.0011d
(d)
Figure 11: ESI-mass spectra of cyt c in water containing 3% methanol and 0.5 mM ammonium acetate at (a) pH 6.4, (b) pH 4.2, (c) pH 2.6, and (d) pH 2.3. The pH was adjusted by the addition of hydrochloric acid. (Reprinted with permission from Biochemistry [80], Copyright 1997, American Chemical Society).