MASS SPECTROMETORIC DATA ANALYZING APPARATUS AND ANALYZING METHOD

摘要

A tag database establishment section converts, based on information such as an amino acid sequence of an identified peptide and m/z of a peak, a sequence tag indicating a partial sequence and information related to the tag into a database and creates a tag database. When MS2 spectrum information is obtained by measuring a target peptide, a sequence tag acquisition section executes, on the tag database, a search based on coincidence of the m/z of the peak and the like and extracts a sequence tag with high reliability. A peptide identification section performs, based on an amino acid sequence of the sequence tag, m/z of a precursor ion, and the like, a search by a sequence tag search method taking into account a post-translational modification or a variation and identifies a peptide.

主权项

1. A mass spectrometric data analyzing apparatus that identifies, based on MSn spectrum data collected by executing an MSn analysis (n is an integer equal to or larger than 2) on a test sample, a target peptide in the test sample, the mass spectrometric data analyzing apparatus comprising:
a) a tag database establishment section for establishing a sequence tag database in advance obtaining, from an amino acid sequence of a known peptide and MSn spectrum information, a sequence tag, which is a partial amino acid sequence, and spectrum peak information corresponding to the sequence tag; b) a sequence tag acquisition section for acquiring a sequence tag of the target peptide by collating peak information extracted from a measured MSn spectrum obtained for the test sample with information in the sequence tag database; and c) a peptide identification section for identifying a peptide by performing a database search in the sequence tag database or in a protein database using, as search conditions, the sequence tag for the target peptide obtained by the sequence tag acquisition section and mass of a precursor ion deriving from the target peptide.