title: Construction of a hybrid quadrupole/Fourier transform ion cyclotron resonance mass spectrometer for versatile MS/MS above 10 kDa.
abstract: Technological advancements including an open-cylindrical Penning trap with capacitively coupled ICR cell, selective ion accumulation with a resolving quadrupole, and a voltage gradient used during ion extraction from an octopole ion trap, have individually improved dynamic range and sensitivity in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Documented here is a new instrument utilizing these technologies toward the robust detection and fragmentation of biomolecules >10 kDa. Up to 55-fold enhancement in ion population by selective ion accumulation combined with 10- to 20- fold signal-to-noise improvement by application of a DC voltage gradient to an accumulation octopole during the ion transfer event offers improved signal-to-noise (or speed) of MS/MS experiments, for proteins from Methanococcus jannaschii and Saccharomyces cerevisiae whole cell lysates. After external quadrupole filtering with a 40 m/z window, three proteins were fragmented (and identified) in parallel from the database of Methanococcus jannaschii. Electron capture dissociation (ECD) of an intact yeast protein provides extensive sequence information resulting in a high degree of localization for an N-terminal acetylation. Hybrid fragmentation, infrared multiphoton dissociation (IRMPD) followed by low energy electrons (ECD), with the electron source located laterally off the z-axis and external to the magnet bore, presents a strategy for identification of proteins by means of the sequence tag approach. Automated implementation of diverse MS(n) approaches in a Q-FTMS instrument promises to help realize "top-down" proteomics in the future.
authors.affiliation: Department of Chemistry, University of Illinois, Urbana, 61801, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Patrie
authors.forename: Jay P
authors.initials: JP
authors.lastname: Charlebois
authors.forename: David
authors.initials: D
authors.lastname: Whipple
authors.forename: Neil L
authors.initials: NL
authors.lastname: Kelleher
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Hendrickson
authors.forename: John P
authors.initials: JP
authors.lastname: Quinn
authors.forename: Alan G
authors.initials: AG
authors.lastname: Marshall
authors.forename: Biswarup
authors.initials: B
authors.lastname: Mukhopadhyay
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D011506:Proteins / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000737:chemistry; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein / Q000295:instrumentation* / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation* / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins