Final ProgramCPSA 2011
Science and Technology Coming Together to Make a Difference
October 3 - 6, 2011
Bucks County Sheraton Hotel
Langhorne, PA
Poster Abstract #37
Automated Deisotoping and Charge Deconvolution of High-Resolution LCMS Data
1) Novatia, LLC, Monmouth Junction, NJ 08852; 2) Positive Probability, Ltd., UK
Since mass spectrometers do not measure mass, but mass-to-charge (m/z) ratios, software algorithms must be employed to convert the raw m/z data to useful mass information. This is particularly important for processing and interpretation of biomolecule LCMS data where multiply-charged ions are observed. For example, ProMass deconvolution software allows entire biomolecule LCMS data sets to be processed directly from the MS sample run list and reported in a simplified web-based format. Unit resolution mass spectrometers such as ion traps and quadrupole instruments result in unresolved isotopic clusters above mass ~2000-3000 Da. Therefore, the charge deconvolution process for “normal resolution” data cannot reliably utilize the isotopic pattern to determine uncharged mass. In these cases, the deconvolution process returns a result that is closest to the isotopic average mass of the species being analyzed. With the widespread proliferation of high-resolution mass spectrometers, new deconvolution algorithms need to be utilized to take advantage of the mass resolution and the information contained in the experimentally observed isotopic patterns. A deisotoping approach allows determination of exact (monoisotopic) mass and offers a marked increase in mass accuracy relative to average mass determination methods. In this presentation, we demonstrate the use of a new data processing package that utilizes the Positive Probability, Ltd. (PPL) deisotoping algorithm integrated into the ProMass software workflow. Once an isotopic unit cell formula and instrumental peak shape have been modeled within the PPL software, the deisotoping method is saved and referenced by a ProMass parameter file. The ProMass software is operated in the normal way, with the only change that a PPL-enabled parameter set is utilized during processing. Data will be shown that demonstrates the utility of the software for automated exact mass of determination of peptides, small-medium sized proteins, and oligonucleotides.
Return to program