IMPROVED PROTEOMIC ANALYSIS

摘要

The instant invention relates to improved methods and systems for proteomic analysis using MS (mass spectrometry) data, particularly tandem mass spectrometry (MS/MS) data. The method comprises searching a first level database using sequence information generated by MS/MS obtained from a peptide selected from a digested protein sample. A second level database (which is smaller and contains only the candidate proteins) is then searched to identify the identify of the protein containing the selected peptide. More levels of even smaller databases can be generated for successive rounds of searches if the previous round of search does not unequivocally identify the protein containing the selected peptide(s). The method may be carried out on a range of mass spectrometers including a tandem mass spectrometer (MS/MS), an ion trap mass spectrometer or others capable of generating MS and MS/MS data.