High-energy collision-induced dissociation of multiply charged polypeptides produced by electrospray

Abstract

The recent commercial implementation of an electrospray source on a four-sector mass spectrometer has allowed the study of high-energy collisional activation of multiply charged cations. With this configuration, higher mass-to-charge ratios can be accommodated in both precursor ion selection and fragment ion detection. Good mass accuracy facilitates analysis of fragment ions and allows more reliable mechanistic correlation of these fragments. A convenient scheme was devised to permit the use of kilovolt potentials in both MS-I and MS-II, with precursors of varying charge states. Algorithms were devised to assign masses of different types of multiply charged fragment ions. Nine polypeptides were studied in the mass range 2000-5000 Da. Through this entire mass range, fragment ions were observed to be amply formed by cleavages in both the backbone and side chains, analogous to high-energy collisional activation of singly charged ions. This stands in sharp contrast to the patterns reported with low-energy, multiple collisions. Abundances of sequence ion series are influenced by the positions of basic residues. Analysis of charge distributions in fragment ions also indicates that the charges tend to be spread out across the peptides.

Special feature: Perspective. Mass spectrometric peptide and protein charting

“…The (E Lab ) appearance of most of the fragment ions at m /z values close to that of the precursor ion is typical for tandem mass spectra of multiply charged polypeptides. 116 protein charts of mature rats. Indeed, two trypsindegradable compounds with RMM 5787 and 5707 were found ( Table 1) that exhibit di †erent relative abundances in males (D2 : 1) and females (D1 : 2).…”

Massive cluster impact ionization on a four sector tandem mass spectrometer

“…Accelerating voltages and collision cell potentials for the multiply charged precursors were calculated as described earlier. 13 Product ion spectra from singly and doubly charged precursors were obtained by B/E linked scanning of MS-2 from 0 to ([M -H I -+ 10%) in order to collect all the products with charge states -1 and -2. Scan rate and resolution were set as previously described.'…”

Characterization of a microdialysis approach to prepare polymerase chain reaction products for electrospray ionization mass spectrometry using on-line ultraviolet absorbance measurements and inductively coupled plasma-atomic emission spectroscopy

“…[1][2][3][4][5] The ability of ESI-MS to provide essential sequence and structural information of biopolymers by collisionally induced dissociation has been shown for deoxyribonucleic acids (DNA), 6,7 ribonucleic acids, 6,[8][9][10] peptides [11][12][13][14][15] and peptide nucleic acids. 16 A major hindrance in using ESI-MS for the analysis of biopolymers is interference due to matrix effects (e.g.…”