Fig. 3. Concomitant N-terminal c-ions and C-terminal bridged z-ions produced in the ECD spectra of the anti-DNP IgG1 F(ab′)2 precursor, revealing that the disulfide bonds remain intact. (A) The c-ions (purple box) are well separated in the m/z window from their concomitant bridged z-ions (red dotted box) in the native ECD-MS spectrum of the IgG1 anti-DNP F(ab′)2 molecule. Because they are minimally affected by signal overlapping, bridged z-ions in the solid red box were selected for further analysis. (B) Alignment of the c-ions (purple) with the bridged z-ions (red) after charge deconvolution reveals that their mass adds up to that of the intact 99.2 kDa F(ab′)2 precursor.
