Identification method of protein by secondary mass spectrometry based on the matching of positive and negative library feature information

Abstract

The invention discloses a tandem mass spectrometric identification method for protein based on matching between characteristic information of a target database and a decoy database. The method mainly carries out statistics of matching between experimental peaks of different types and theoretical peaks of the target database and the decoy database in different error ranges and intensity intervals, then extracts novel characteristic information of tandem spectra and carries out mathematical quantification, and finally, fusing the quantified novel characteristic information into a protein tandem mass spectrometric identification algorithm scoring model. To verify reliability of PepFind algorithm, the PepFind algorithm is tested by using data sets generated by different mass spectrometric platforms; and identification results of the PepFind algorithm are compared with identification results obtained by using widely-applied commercial and related open-source tandem mass spectrometric identification software under the condition that FDR is 1%, and comparison results show that the PepFind algorithm has better identification number and sensitivity to experimental spectra. The tandem mass spectrometric identification method for protein based on matching between characteristic information of the target database and the decoy database can obviously improve the effective mass spectrometric number and the peptide fragment number of protein.

Description

technical field [0001] The invention relates to the field of protein secondary mass spectrometry identification, in particular to a protein secondary mass spectrometric identification method based on the matching of positive and negative library feature information. Background technique [0002] Tandem mass spectrometry (LC-MS / MS) is widely used in the identification and quantification of complex protein mixtures. In a traditional LC-MS / MS experiment, the peptide mixture obtained after enzymatic hydrolysis is separated by strong cation exchange chromatography and reversed-phase chromatography, and the obtained peptides flow into the biological mass spectrometer in sequence according to their own hydrophobicity. Using electrospray technology or Laser desorption technology ionizes and fragments the peptides entering the mass spectrometer, and simultaneously measures the mass information of the corresponding fragment ions, then selects the first few fragment ions with the highe...

AI Technical Summary

Problems solved by technology

③ The error of the biological mass spectrometer itself: different error precision can greatly affect the efficiency and accuracy of database search

However, based on the premise of positive and negative libraries, exploring the matching characteristics of different types of fragment ions in different mass error ranges and intensity intervals is ignored in the existing protein secondary mass spectrometry identification algorithms.

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