We propose to develop a tandem mass spectrometer in which both MS1 and MS2 are time-of-flight (TOF) mass analyzers. Each mass analyzer will combine pulsed and delayed ion extraction with reflection focusing. Pulsed extraction will provide space focusing as well as permitting relaxation of metastable ions, which constitute the major limitation in resolution for high mass ions. Energy focusing will be provided by the reflectron, with a spatially focused beam of stable molecular and fragment ions as its input. The design will be a versatile one in that the ion source, both reflectron flight regions, and the collision chamber can be electrically floated from 0 to =/-6kV. this will enable us to compare and evaluate high energy collision induced dissociation (CID), low energy CID, and endothermic ion molecule reactions schemes for producing product ion (sequence) spectra as to both efficiency and focusing (mass resolution). Einsel lens focusing and quadrupole steering will provide a compact beam to enable the use of a relatively short flight tube and large reflectron angle, while maintaining excellent reflectron focusing. For high energy collisions, both deep reflectrons and product ion reacceleration will be examined for their focusing capabilities. Decelleration lenses, with high focusing, will be used to inject ions into the collision chamber at the very low energies needed for endothermic reactions. In the case of beam energy is consumed in the formation of the product ions, so that these ions at rest will be reaccelerated by pulsed ion extraction.
The aim of the project is to produce an optimal configuration for the rapid analysis of tryptic (and other enzymatic) digests of proteins, when combined with high performance liquid chromatography (HPLC). The high repetition rate of the TOF analyzer, combined with high speed integrated transient recording developed in our laboratory, will enable us to obtain sequence information (in real time) from both separated and co-eluting peptides.
|Smit, John; Kaltashov, Igor A; Kaltoshov, Igor A et al. (2008) Structure of a novel lipid A obtained from the lipopolysaccharide of Caulobacter crescentus. Innate Immun 14:25-37|
|Cotter, R J; Fancher, C; Cornish, T J (1999) Miniaturized time-of-flight mass spectrometer for peptide and oligonucleotide analysis. J Mass Spectrom 34:1368-72|
|Dotson, G D; Kaltashov, I A; Cotter, R J et al. (1998) Expression cloning of a Pseudomonas gene encoding a hydroxydecanoyl-acyl carrier protein-dependent UDP-GlcNAc acyltransferase. J Bacteriol 180:330-7|
|Odegaard, T J; Kaltashov, I A; Cotter, R J et al. (1997) Shortened hydroxyacyl chains on lipid A of Escherichia coli cells expressing a foreign UDP-N-acetylglucosamine O-acyltransferase. J Biol Chem 272:19688-96|
|Cornish, T J; Cotter, R J (1997) High-order kinetic energy focusing in an end cap reflectron time-of-flight mass spectrometer. Anal Chem 69:4615-8|
|White, K A; Kaltashov, I A; Cotter, R J et al. (1997) A mono-functional 3-deoxy-D-manno-octulosonic acid (Kdo) transferase and a Kdo kinase in extracts of Haemophilus influenzae. J Biol Chem 272:16555-63|
|Kaltashov, I A; Doroshenko, V; Cotter, R J et al. (1997) Confirmation of the structure of lipid A derived from the lipopolysaccharide of Rhodobacter sphaeroides by a combination of MALDI, LSIMS, and tandem mass spectrometry. Anal Chem 69:2317-22|
|Kaltashov, I A; Doroshenko, V M; Cotter, R J (1997) Gas phase hydrogen/deuterium exchange reactions of peptide ions in a quadrupole ion trap mass spectrometer. Proteins 28:53-8|
|Cordero, M M; Cornish, T J; Cotter, R J et al. (1995) Sequencing peptides without scanning the reflectron: post-source decay with a curved-field reflectron time-of-flight mass spectrometer. Rapid Commun Mass Spectrom 9:1356-61|
|Fabris, D; Vestling, M M; Cordero, M M et al. (1995) Sequencing electroblotted proteins by tandem mass spectrometry. Rapid Commun Mass Spectrom 9:1051-5|
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