1. Electrospray-assisted laser desorption ionization mass spectrometry (ELDI-MS) with an infrared laser for characterizing peptides and proteins
- Author
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Eli Margalith, Mark W. Little, Rachel R. Ogorzalek Loo, Joseph A. Loo, and Ivory X. Peng
- Subjects
Electrospray ,Chromatography ,Protein mass spectrometry ,Ubiquitin ,Chemistry ,Lasers ,Far-infrared laser ,Analytical chemistry ,Proteins ,Bradykinin ,Mass spectrometry ,Biochemistry ,Article ,Sample preparation in mass spectrometry ,Analytical Chemistry ,Surface-enhanced laser desorption/ionization ,Matrix-assisted laser desorption/ionization ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Electrochemistry ,Environmental Chemistry ,Sample preparation ,Peptides ,Spectroscopy ,Carbonic Anhydrases - Abstract
An electrospray-assisted laser desorption/ionization source with an infrared OPO laser (IR-ELDI) was constructed and optimized for peptide and protein mass spectrometry analysis. Similar to ELDI with an ultraviolet laser, IR-ELDI generates multiply charged molecules for peptides and proteins measured under ambient sampling conditions. Both samples in the dried state and analyte solutions can be directly measured by IR-ELDI without the presence of a conventional MALDI matrix. However, the analysis of sample solutions is shown to greatly enhance the sensitivity of the mass spectrometry measurement, as a 100-fold sensitivity gain for peptide measurements was measured. The limit of detection of IR-ELDI was determined to be 250 fmol for bradykinin (1.1 kDa), 100 fmol for ubiquitin (8.6 kDa), and 500 fmol for carbonic anhydrase (29 kDa). IR-ELDI is amenable for MS and MSn analysis for proteins up to 80 kDa transferrin. IR-ELDI-MS may be a useful tool for protein sequencing analysis from complex biological matrices, with minimal sample preparation required.
- Published
- 2010