Surface-induced dissociation of multiply-protonated proteins.
A novel surface design compatible with the open cell geometry allows nonglancing angle collisions of selected ions stored in a Fourier transform mass spectrometer. Dissociation efficiencies of 36%, 22%, and 14% are achieved for gramicidin S, melittin, and carbonic anhydrase (29 kDa), respectively. Ion neutralization by the surface, which is highly competitive for many singly-charged ions, is minimal, and dissociation products of hypervalent neutral species are not detected. Instead, the spectra are similar to those from collisionally activated and infrared multiphoton dissociation; the fragmentation pathways are relatively independent of the method of energy deposition. For carbonic anhydrase, however, the single event excitation inherent to surface-induced dissociation appears to minimize secondary fragmentation, a critical advantage for tandem mass spectrometry of such large ions. Electrically floating the open cell below ground greatly enhances the collection efficiency.
Chorush
R A
RA
Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301.
Little
D P
DP
Beu
S C
SC
Wood
T D
TD
McLafferty
F W
FW
D002256:Carbonic Anhydrases / Q000737:chemistry; D006096:Gramicidin / Q000737:chemistry; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods; D008555:Melitten / Q000737:chemistry; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D011522:Protons; D013057:Spectrum Analysis / Q000379:methods*
D007477:Ions; D011506:Proteins; D011522:Protons; D006096:Gramicidin; D008555:Melitten; D002256:Carbonic Anhydrases