Abstract

The long-term objective of this work is to develop improved methods for identifying and characterizing large molecules, and to apply these methods to various biological problems. Time-of-flight (TOF) techniques will be used to determine the mass spectra of ions ejected from organic compounds by electrospray. (SIMS), and by laser desorption (LDMS), as well as ions produced by electrospray. Structural information about the sample molecules will be obtained from the normal mass spectra and from the measurement of correlations between neutral and charged daughters in a reflecting TOF spectrometer. These measurements will be made in three time-of-flight mass spectrometers constructed in our laboratory: 1) linear spectrometer (TOFI); 2) a reflecting instrument (TOFII), which gives improved resolution and enables measurement of correlations between neutral and charged fragments; 3) a second reflecting instrument (TOFIII), not yet in full operation, which will be modified for use with an electrospray ion source. The laboratory possesses a versatile laser system, built by Lumonics; it consists of a high repetition rate excimer laser with gas purifier, a tuneable dye laser, and a frequency doubler. A small nitrogen laser is also available. The lasers will be used for laser desorption and for experiments on ion dissociation after acceleration. Specifically it is proposed: 1. To make improvements in instrumentation and technique. The use of an I- ion source (already constructed) for desorption will be investigated. Laser desorption will be carried out on the reflecting instrument (TOFII) with the hope of obtaining improved resolution. An electrospray ion source will be installed in TOF III. 2. To carry out studies on the basic physics of laser desorption, secondary ion emission, particle detection and ion dissociation, so as to obtain a better understanding of these processes and to facilitate their application to biological problems. The emission of electrons and secondary ions from various struck by large molecules will be investigated. 3. To apply time-of-flight mass spectrometry to various samples of biological interest, in particular to peptides, proteins and nucleotides.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM030605-10A1
Application #
3278400
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1982-06-01
Project End
1995-03-31
Budget Start
1992-04-01
Budget End
1993-03-31
Support Year
10
Fiscal Year
1992
Total Cost
Indirect Cost

  Institution

Name
University of Manitoba
Department
Type
DUNS #
207584707
City
Winnipeg
State
MB
Country
Canada
Zip Code
R3 2-N2

  Publications

Lei, Q P; Cui, X; Kurtz Jr, D M et al. (1998) Electrospray mass spectrometry studies of non-heme iron-containing proteins. Anal Chem 70:1838-46
Rose, K; Zeng, W; Regamey, P O et al. (1996) Natural peptides as building blocks for the synthesis of large protein-like molecules with hydrazone and oxime linkages. Bioconjug Chem 7:552-6
Donald, L J; Chernushevich, I V; Zhou, J et al. (1996) Preparation and properties of pure, full-length IclR protein of Escherichia coli. Use of time-of-flight mass spectrometry to investigate the problems encountered. Protein Sci 5:1613-24
Sevinc, M S; Ens, W; Loewen, P C (1995) The cysteines of catalase HPII of Escherichia coli, including Cys438 which is blocked, do not have a catalytic role. Eur J Biochem 230:127-32
Verentchikov, A N; Ens, W; Standing, K G (1994) Reflecting time-of-flight mass spectrometer with an electrospray ion source and orthogonal extraction. Anal Chem 66:126-33
Tang, X J; Brewer, C F; Saha, S et al. (1994) Investigation of protein-protein noncovalent interactions in soybean agglutinin by electrospray ionization time-of-flight mass spectrometry. Rapid Commun Mass Spectrom 8:750-4
Tocchio, R M; Williams, P T; Mayer, F J et al. (1993) Laser debonding of ceramic orthodontic brackets. Am J Orthod Dentofacial Orthop 103:155-62
Ens, W; Main, D E; Standing, K G et al. (1988) Comparison of relative quasi-molecular ion yields for 8-keV ion and 252Cf fission fragment bombardment. Anal Chem 60:1494-8
Main, D E; Ens, W; Beavis, R et al. (1987) Redox reactions occurring during secondary ion mass spectrometry of some heteroanthracycline antitumor antibiotic precursors. Biomed Environ Mass Spectrom 14:91-6
Lafortune, F; Beavis, R; Tang, X et al. (1987) Narrowing the gap between keV and fission fragment secondary ion yields with nitrocellulose. Rapid Commun Mass Spectrom 1:114-6

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