GPM-MRM is functionality that has been added to The GPM to assist researchers in finding signature combinations of peaks in MS/MS spectra. Spectra can be searched by mass, accession number of peptide sequence, and the results can be pared down by fragment mass presence or uniqueness.
The default values for some of the search parameters are as follows:
A search can be performed with one of the following sets of data:
For any of the above searches, providing the fragment ion mass will mask out results that did not include a fragment ion within the given range of the supplied fragment ion mass.
The fragment ion mass range is used to classify fragment masses as unique or not. In a result set, and two masses between different results within the fragment ion mass range are considered to be the same, and therefore non-unique. A larger fragment ion mass range will lead to fewer fragment ions being considered unique.
The data returned by the search returns in the following order:
Unique fragment ion masses are colour-coded for fast identification, and the rows of results are ordered from fewest to most corresponding accession numbers. The peak/intensity tables can be displayed either by ascending weight or descending intensity. Non-unique peaks can be masked out for a simplified display.
The links below demonstrate the different search and display parameters.