title: Ultra high resolution linear ion trap Orbitrap mass spectrometer (Orbitrap Elite) facilitates top down LC MS/MS and versatile peptide fragmentation modes.
abstract: Although only a few years old, the combination of a linear ion trap with an Orbitrap analyzer has become one of the standard mass spectrometers to characterize proteins and proteomes. Here we describe a novel version of this instrument family, the Orbitrap Elite, which is improved in three main areas. The ion transfer optics has an ion path that blocks the line of sight to achieve more robust operation. The tandem MS acquisition speed of the dual cell linear ion trap now exceeds 12 Hz. Most importantly, the resolving power of the Orbitrap analyzer has been increased twofold for the same transient length by employing a compact, high-field Orbitrap analyzer that almost doubles the observed frequencies. An enhanced Fourier Transform algorithm-incorporating phase information-further doubles the resolving power to 240,000 at m/z 400 for a 768 ms transient. For top-down experiments, we combine a survey scan with a selected ion monitoring scan of the charge state of the protein to be fragmented and with several HCD microscans. Despite the 120,000 resolving power for SIM and HCD scans, the total cycle time is within several seconds and therefore suitable for liquid chromatography tandem MS. For bottom-up proteomics, we combined survey scans at 240,000 resolving power with data-dependent collision-induced dissociation of the 20 most abundant precursors in a total cycle time of 2.5 s-increasing protein identifications in complex mixtures by about 30%. The speed of the Orbitrap Elite furthermore allows scan modes in which complementary dissociation mechanisms are routinely obtained of all fragmented peptides.
authors.affiliation: Department of Proteomics and Signal Transduction, Max-Planck Institute for Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Michalski
authors.forename: Eugen
authors.initials: E
authors.lastname: Damoc
authors.forename: Oliver
authors.initials: O
authors.lastname: Lange
authors.forename: Eduard
authors.initials: E
authors.lastname: Denisov
authors.forename: Dirk
authors.initials: D
authors.lastname: Nolting
authors.forename: Mathias
authors.initials: M
authors.lastname: Müller
authors.forename: Rosa
authors.initials: R
authors.lastname: Viner
authors.forename: Jae
authors.initials: J
authors.lastname: Schwartz
authors.forename: Philip
authors.initials: P
authors.lastname: Remes
authors.forename: Michael
authors.initials: M
authors.lastname: Belford
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Dunyach
authors.forename: Juergen
authors.initials: J
authors.lastname: Cox
authors.forename: Stevan
authors.initials: S
authors.lastname: Horning
authors.forename: Matthias
authors.initials: M
authors.lastname: Mann
authors.forename: Alexander
authors.initials: A
authors.lastname: Makarov
mesh_terms: D002853:Chromatography, Liquid; D006367:HeLa Cells; D006801:Humans; D010446:Peptide Fragments / Q000032:analysis* / Q000378:metabolism*; D020543:Proteome / Q000032:analysis* / Q000378:metabolism*; D040901:Proteomics / Q000295:instrumentation* / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000295:instrumentation* / Q000379:methods
chemical_list: D010446:Peptide Fragments; D020543:Proteome