Data analysis method for quantitative methods for b, y fragment ion pairs on second-level mass spectra from peptide fragments of same mass on first-level mass spectra

Abstract

The invention relates to the technical field of proteomics, in particular to a data analysis method for quantitative methods for b, y fragment ion pairs on second-level mass spectra from peptide fragments of same mass on first-level mass spectra. The method is written by using a Matlab language and runs in a Matlab interface, and qualitative information of peptide fragments and protein is obtained by making ratio through extracting peak intensity information of b, y fragment ion pairs on tandem mass spectra and on the basis of a qualitative result of protein obtained by a SEQUEST search engine. According to the method, an optimization module for 'spectrogram resolution' is also added, so that the influence of a b, y fragment ion pair fragmentation spectrogram on the qualitative correctness of the peptide fragments is reduced. According to the method, a z statistical magnitude is also constructed to calculate the significance of quantitative protein, so that a reference evidence is provided for determining up-regulated and down-regulated changed protein in a practical sample. The invention provides a universal, open and accurate quantitative analysis means for development and application of novel quantitative proteomics methods for the b, y fragment ion pairs on second-level mass spectra from peptide fragments of same mass on first-level mass spectra.

Description

Technical field [0001] The present invention is a protein group science technology, which specifically involves a data analysis method for quantitative methods for the same quality of the same quality B and Y fragments. Background technique [0002] The quantitative protein group method is constantly being improved and innovative. Recently, the same quality of the same quality B. Y fragments ions have attracted more and more attention and attention to the quantitative protein group.The scale data analysis method, the only related analysis software isobaric Q, is mainly based on the data result generated by the Mascot search engine, and it cannot be used for all the same quality, the second level B, the y fragments ion to the quantitative protein group to learnmethod.In addition, the same quality second -level B, Y fragments ions to quantitative protein groups while providing accurate quantitative results, in terms of qualitative in terms of qualitative, due to the phenomenon of c...

AI Technical Summary

Problems solved by technology

[0002] Quantitative proteomics methods are constantly being improved and innovated. Recently, proteomics methods for quantitative proteomics of the same mass and secondary b, y fragment ion pairs are becoming more and more popular. It has received more and more attention and attention, but currently lacks effective and automated large-scale data analysis methods. The only relevant analysis software, Isobaric Q, is mainly based on the data results generated by the MASCOT search engine, and cannot be used for all levels of the same A proteomic approach to the quantification of mass, secondary b, y fragment ion pairs

In addition, the proteomics method for quantifying the secondary b, y fragment ion pairs of the same mass at the same level provides accurate quantitative results, but in terms of qualitative aspects, due to the coexistence of the secondary b, y fragment ion pairs, the target peptide may be reduced. The search score of the peptide segment will lead to the loss of qualitative information of the peptide segment, or even a wrong match, which will affect the accuracy of subsequent quantification.

In the current database search engines, such as SEQUEST and MASCOT, there is no effective module for searching, processing and optimizing such tandem mass spectra.

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