A rapid identification method for cross-linked dipeptides

Abstract

The invention provides a crosslinking dipeptide rapid identification method, comprising: 1) extracting effective spectrum peaks in a to-be-identified series-connected spectrogram, according to mass corresponding to each effective spectrum peak, searching a fragment index, to obtain a corresponding peptide fragment sequence as a candidate [alpha] peptide sequence, wherein the fragment index records mass of each fragment and the peptide fragment sequence corresponding to the mass of each fragment; 2) for each candidate [alpha] peptide sequence, according to parent ion mass of the to-be-identified series-connected spectrogram, calculating corresponding [beta] peptide mass, to obtain a corresponding candidate [beta] peptide sequence, combining the candidate [alpha] peptide sequence with the corresponding candidate [beta] peptide sequence, to obtain candidate crosslinking dipeptide; 3) matching the candidate crosslinking dipeptide obtained in the step 2) with the series-connected spectrogram in a fine manner, to obtain an identification result. The method does not need to use a special cross-linking agent, searching speed is fast, identification efficiency is high, and search sensitivity is high.

Description

technical field [0001] The invention relates to the technical field of bioinformatics, in particular, the invention relates to a rapid identification method for cross-linked dipeptides. Background technique [0002] Chemical cross-linking combined with mass spectrometry (referred to as cross-linking mass spectrometry) is an effective method for large-scale research on protein-protein interactions and protein folding. The core research and identification object is cross-linked dipeptide, which originates from the Synlocation points provide information that sequences are far apart but spatially close together. In cross-linked mass spectrometry, the identification of cross-linked dipeptides is mainly achieved by database search technology of tandem spectra. However, unlike the traditional single-peptide sequence search, the candidate space of cross-linked dipeptide database search grows to the square of the original single-peptide sequence, which brings challenges to large-sca...

AI Technical Summary

Problems solved by technology

However, in this method, nearly half of the peptides in the sequence library have to be roughly scored with each spectrum, which has the problem of a large amount of calculation, which leads to low identification efficiency

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