Matrix-Assisted Ionization and Tandem Mass Spectrometry Capabilities in Protein Biomarker Characterization-An Initial Study Using the Small Cell Lung Cancer Biomarker Progastrin Releasing Peptide as a Model Compound.
Trine Grønhaug HalvorsenMaren Christin Stillesby LevernæsCecilie RostingPublished in: Journal of the American Society for Mass Spectrometry (2020)
This initial study evaluates vacuum matrix-assisted ionization (vMAI) mass spectrometry (MS) for identification and determination of tryptic peptides from the biomarker protein progastrin releasing peptide (ProGRP). Similar peptides and charge states were observed as in liquid chromatography (LC) electrospray ionization (ESI) MS. The prolonged ion duration in vMAI with similar charge states as in ESI was advantageous for determining the MS/MS fragmentation conditions compared to MAI. It is assumed that the vacuum ionization conditions lower the detection limits of the experiment. This may be the reason vMAI combined with high resolution MS enabled detection of tryptic peptides from more digested proteins than MAI selected reaction monitoring MS. Additionally, MAI ion mobility spectrometry MS (MAI-IMS-MS) was evaluated for differentiation of intact protein isoforms, successfully enabling differentiation of the isoforms by drift time selection. Examples are both shown for model proteins bovine serum albumin, cytochrome C, and lysozyme and the clinically relevant small cell lung cancer protein biomarker ProGRP, which exists in three isoforms. Coupling with the vacuum ionization conditions using a dedicated vacuum-probe source MAI enables information to be extracted readily as with conventional approaches, just faster.
Keyphrases
- mass spectrometry
- gas chromatography
- liquid chromatography
- tandem mass spectrometry
- ms ms
- high resolution
- ultra high performance liquid chromatography
- high resolution mass spectrometry
- high performance liquid chromatography
- small cell lung cancer
- solid phase extraction
- simultaneous determination
- amino acid
- capillary electrophoresis
- liquid chromatography tandem mass spectrometry
- protein protein
- multiple sclerosis
- healthcare
- loop mediated isothermal amplification
- small molecule
- solar cells
- heavy metals