FIGURE 4.
ESI-MS spectra of Ctr11-14 treated with 1 and 2 eq of CuSO4 (A,C)and magnification of the doubly charged peaks (cyan and blue dashed boxes) displayed in (B,D), respectively; the insets show the calculated isotopic distributions. (E) Intensity of doubly charged ESI-MS peaks of different Ctr11-14 species as a function of Cu(II):peptide ratio.
