Measurement of Individual Ions Sharply Increases the Resolution of Orbitrap Mass Spectra of Proteins.
Anal Chem
; 91(4): 2776-2783, 2019 02 19.
Article
in En
| MEDLINE
| ID: mdl-30609364
ABSTRACT
It is well-known that with Orbitrap-based Fourier-transform-mass-spectrometry (FT-MS) analysis, longer-time-domain signals are needed to better resolve species of interest. Unfortunately, increasing the signal-acquisition period comes at the expense of increasing ion decay, which lowers signal-to-noise ratios and ultimately limits resolution. This is especially problematic for intact proteins, including antibodies, which demonstrate rapid decay because of their larger collisional cross-sections, and result in more frequent collisions with background gas molecules. Provided here is a method that utilizes numerous low-ion-count spectra and single-ion processing to reconstruct a conventional m/ z spectrum. This technique has been applied to proteins varying in molecular weight from 8 to 150 kDa, with a resolving power of 677â¯000 achieved for transients of carbonic anhydrase (29 kDa) with a duration of only â¼250 ms. A resolution improvement ranging from 10- to 20-fold was observed for all proteins, providing isotopic resolution where none was previously present.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Mass Spectrometry
/
Proteins
Limits:
Animals
/
Humans
Language:
En
Journal:
Anal Chem
Year:
2019
Type:
Article
Affiliation country:
United States